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Xhima K, Ottoy J, Gibson E, Zukotynski K, Scott C, Feliciano GJ, Adamo S, Kuo PH, Borrie MJ, Chertkow H, Frayne R, Laforce R, Noseworthy MD, Prato FS, Sahlas DJ, Smith EE, Sossi V, Thiel A, Soucy JP, Tardif JC, Goubran M, Black SE, Ramirez J. Distinct spatial contributions of amyloid pathology and cerebral small vessel disease to hippocampal morphology. Alzheimers Dement 2024. [PMID: 38574400 DOI: 10.1002/alz.13791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 01/22/2024] [Accepted: 02/09/2024] [Indexed: 04/06/2024]
Abstract
INTRODUCTION Cerebral small vessel disease (SVD) and amyloid beta (Aβ) pathology frequently co-exist. The impact of concurrent pathology on the pattern of hippocampal atrophy, a key substrate of memory impacted early and extensively in dementia, remains poorly understood. METHODS In a unique cohort of mixed Alzheimer's disease and moderate-severe SVD, we examined whether total and regional neuroimaging measures of SVD, white matter hyperintensities (WMH), and Aβ, as assessed by 18F-AV45 positron emission tomography, exert additive or synergistic effects on hippocampal volume and shape. RESULTS Frontal WMH, occipital WMH, and Aβ were independently associated with smaller hippocampal volume. Frontal WMH had a spatially distinct impact on hippocampal shape relative to Aβ. In contrast, hippocampal shape alterations associated with occipital WMH spatially overlapped with Aβ-vulnerable subregions. DISCUSSION Hippocampal degeneration is differentially sensitive to SVD and Aβ pathology. The pattern of hippocampal atrophy could serve as a disease-specific biomarker, and thus guide clinical diagnosis and individualized treatment strategies for mixed dementia.
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Affiliation(s)
- Kristiana Xhima
- Dr. Sandra E. Black Centre for Brain Resilience and Recovery, LC Campbell Cognitive Neurology, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Julie Ottoy
- Dr. Sandra E. Black Centre for Brain Resilience and Recovery, LC Campbell Cognitive Neurology, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Erin Gibson
- Dr. Sandra E. Black Centre for Brain Resilience and Recovery, LC Campbell Cognitive Neurology, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Katherine Zukotynski
- Dr. Sandra E. Black Centre for Brain Resilience and Recovery, LC Campbell Cognitive Neurology, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
- Departments of Medicine and Radiology, McMaster University, Hamilton, Ontario, Canada
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Christopher Scott
- Dr. Sandra E. Black Centre for Brain Resilience and Recovery, LC Campbell Cognitive Neurology, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Ginelle J Feliciano
- Dr. Sandra E. Black Centre for Brain Resilience and Recovery, LC Campbell Cognitive Neurology, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Sabrina Adamo
- Dr. Sandra E. Black Centre for Brain Resilience and Recovery, LC Campbell Cognitive Neurology, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Phillip H Kuo
- Departments of Medical Imaging, Medicine, Biomedical Engineering, University of Arizona, Tucson, Arizona, USA
| | - Michael J Borrie
- Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Howard Chertkow
- Rotman Research Institute, Baycrest Health Sciences, Toronto, Ontario, Canada
| | - Richard Frayne
- Departments of Radiology and Clinical Neuroscience, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Robert Laforce
- Clinique Interdisciplinaire de Mémoire, Département des Sciences Neurologiques, Université Laval, Quebec City, Quebec, Canada
| | - Michael D Noseworthy
- Departments of Medicine and Radiology, McMaster University, Hamilton, Ontario, Canada
- Department of Electrical and Computer Engineering, McMaster University, Hamilton, Ontario, Canada
| | - Frank S Prato
- Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | | | - Eric E Smith
- Department of Clinical Neurosciences and Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Vesna Sossi
- Physics and Astronomy Department and DM Center for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Alexander Thiel
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Jean-Paul Soucy
- Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Jean-Claude Tardif
- Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada
| | - Maged Goubran
- Dr. Sandra E. Black Centre for Brain Resilience and Recovery, LC Campbell Cognitive Neurology, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
- Physical Sciences Platform, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Sandra E Black
- Dr. Sandra E. Black Centre for Brain Resilience and Recovery, LC Campbell Cognitive Neurology, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
- Division of Neurology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Joel Ramirez
- Dr. Sandra E. Black Centre for Brain Resilience and Recovery, LC Campbell Cognitive Neurology, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
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Vora KP, Kumar A, Krishnam MS, Prato FS, Raman SV, Dharmakumar R. Microvascular Obstruction and Intramyocardial Hemorrhage in Reperfused Myocardial Infarctions: Pathophysiology and Clinical Insights From Imaging. JACC Cardiovasc Imaging 2024:S1936-878X(24)00060-3. [PMID: 38613553 DOI: 10.1016/j.jcmg.2024.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 01/10/2024] [Accepted: 02/01/2024] [Indexed: 04/15/2024]
Abstract
Microvascular injury immediately following reperfusion therapy in acute myocardial infarction (MI) has emerged as a driving force behind major adverse cardiovascular events in the postinfarction period. Although postmortem investigations and animal models have aided in developing early understanding of microvascular injury following reperfusion, imaging, particularly serial noninvasive imaging, has played a central role in cultivating critical knowledge of progressive damage to the myocardium from the onset of microvascular injury to months and years after in acute MI patients. This review summarizes the pathophysiological features of microvascular injury and downstream consequences, and the contributions noninvasive imaging has imparted in the development of this understanding. It also highlights the interventional trials that aim to mitigate the adverse consequences of microvascular injury based on imaging, identifies potential future directions of investigations to enable improved detection of disease, and demonstrates how imaging stands to play a major role in the development of novel therapies for improved management of acute MI patients.
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Affiliation(s)
- Keyur P Vora
- Krannert Cardiovascular Research Center, Indiana University School of Medicine/IUHealth, Indianapolis, Indiana, USA. https://twitter.com/KeyurVoraMD
| | - Andreas Kumar
- Northern Ontario School of Medicine, Sudbury, Ontario, Canada. https://twitter.com/AndreasKumarMD
| | | | | | | | - Rohan Dharmakumar
- Krannert Cardiovascular Research Center, Indiana University School of Medicine/IUHealth, Indianapolis, Indiana, USA.
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Kumar A, Connelly K, Vora K, Bainey KR, Howarth A, Leipsic J, Betteridge-LeBlanc S, Prato FS, Leong-Poi H, Main A, Atoui R, Saw J, Larose E, Graham MM, Ruel M, Dharmakumar R. The Canadian Cardiovascular Society Classification of Acute Atherothrombotic Myocardial Infarction Based on Stages of Tissue Injury Severity: An Expert Consensus Statement. Can J Cardiol 2024; 40:1-14. [PMID: 37906238 DOI: 10.1016/j.cjca.2023.09.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 09/09/2023] [Accepted: 09/10/2023] [Indexed: 11/02/2023] Open
Abstract
Myocardial infarction (MI) remains a leading cause of morbidity and mortality. In atherothrombotic MI (ST-elevation MI and type 1 non-ST-elevation MI), coronary artery occlusion leads to ischemia. Subsequent cardiomyocyte necrosis evolves over time as a wavefront within the territory at risk. The spectrum of ischemia and reperfusion injury is wide: it can be minimal in aborted MI or myocardial necrosis can be large and complicated by microvascular obstruction and reperfusion hemorrhage. Established risk scores and infarct classifications help with patient management but do not consider tissue injury characteristics. This document outlines the Canadian Cardiovascular Society classification of acute MI. It is an expert consensus formed on the basis of decades of data on atherothrombotic MI with reperfusion therapy. Four stages of progressively worsening myocardial tissue injury are identified: (1) aborted MI (no/minimal myocardial necrosis); (2) MI with significant cardiomyocyte necrosis, but without microvascular injury; (3) cardiomyocyte necrosis and microvascular dysfunction leading to microvascular obstruction (ie, "no-reflow"); and (4) cardiomyocyte and microvascular necrosis leading to reperfusion hemorrhage. Each stage reflects progression of tissue pathology of myocardial ischemia and reperfusion injury from the previous stage. Clinical studies have shown worse remodeling and increase in adverse clinical outcomes with progressive injury. Notably, microvascular injury is of particular importance, with the most severe form (hemorrhagic MI) leading to infarct expansion and risk of mechanical complications. This classification has the potential to stratify risk in MI patients and lay the groundwork for development of new, injury stage-specific and tissue pathology-based therapies for MI.
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Affiliation(s)
- Andreas Kumar
- Northern Ontario School of Medicine University, and Department of Cardiovascular Sciences, Health Sciences North, Sudbury, Ontario, Canada; Health Sciences North, Sudbury, Ontario, Canada.
| | - Kim Connelly
- Keenan Research Centre for Biomedical Science, Unity Health Toronto, St Michael's Hospital, University of Toronto, and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Keyur Vora
- Krannert Cardiovascular Research Center, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Kevin R Bainey
- University of Alberta, Faculty of Medicine and Dentistry, Mazankowski Alberta Heart Institute, Canadian VIGOUR Centre, Edmonton, Alberta, Canada
| | - Andrew Howarth
- Cardiac Sciences, Faculty of Medicine, University of Calgary, and Libin Cardiovascular Institute, Calgary, Alberta, Canada
| | - Jonathon Leipsic
- Departments of Radiology and Cardiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Suzanne Betteridge-LeBlanc
- Health Sciences North, Sudbury, Ontario, Canada; Northern Ontario School of Medicine University, and Health Sciences North, Sudbury, Ontario, Canada
| | - Frank S Prato
- Lawson Research Institute, University of Western Ontario, London, Ontario, Canada
| | - Howard Leong-Poi
- The Division of Cardiology, St Michael's Hospital, Unity Health Toronto, University of Toronto, Toronto, Ontario, Canada
| | - Anthony Main
- Northern Ontario School of Medicine University, and Department of Cardiovascular Sciences, Health Sciences North, Sudbury, Ontario, Canada; Health Sciences North, Sudbury, Ontario, Canada
| | - Rony Atoui
- Northern Ontario School of Medicine University, and Department of Surgery, Health Sciences North, Sudbury, Ontario, Canada
| | - Jacqueline Saw
- Division of Cardiology, Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Eric Larose
- Department of Medicine, University of Laval, Quebec City, Quebec, Canada
| | - Michelle M Graham
- Division of Cardiology, University of Alberta, Faculty of Medicine and Dentistry, Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada
| | - Marc Ruel
- University of Ottawa Heart Institute, Ottawa, Ontario, Canada
| | - Rohan Dharmakumar
- Krannert Cardiovascular Research Center, Indiana University School of Medicine/IU Health Cardiovascular Institute, Indianapolis, Indiana, USA
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Wilk B, Smailovic H, Sullivan R, Sistermans ER, Butler J, Jago H, Kovacs M, Wisenberg G, Thiessen JD, Prato FS. Myocardial glucose suppression may interfere with the detection of inflammatory cells with FDG-PET as suggested in a canine model of myocardial infarction. EJNMMI Res 2023; 13:90. [PMID: 37823919 PMCID: PMC10570261 DOI: 10.1186/s13550-023-01040-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 10/04/2023] [Indexed: 10/13/2023] Open
Abstract
BACKGROUND After myocardial infarction, fibrosis and an ongoing dysregulated inflammatory response have been shown to lead to adverse cardiac remodeling. FDG PET is an imaging modality sensitive to inflammation as long as suppression protocols are observed while gadolinium enhanced MRI can be used to determine extracellular volume (ECV), a measure of fibrosis. In patients, glucose suppression is achieved variously through a high fat diet, fasting and injection of heparin. To emulate this process in canines, a heparin injection and lipid infusion are used, leading to similar fatty acids in the blood. The aim of this study was to examine the effect of glucose suppression on the uptake of FDG in the infarcted myocardial tissue and also on the determination of ECV in both the infarcted tissue and in the myocardium remote to the zone of infarction during a long constant infusion of FDG and Gd-DTPA. RESULTS Extracellular volume was affected neither by suppression nor the length of the constant infusion in remote and infarcted tissue. Metabolic rate of glucose in infarcted tissue decreased during and after suppression of glucose uptake by lipid infusion and heparin injection. An increase in fibrosis and inflammatory cells was found in the center of the infarct as compared to remote tissue. CONCLUSION The decrease in the metabolic rate of glucose in the infarcted tissue suggests that inflammatory cells may be affected by glucose suppression through heparin injection and lipid infusion.
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Affiliation(s)
- Benjamin Wilk
- Department of Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada.
- Medical Biophysics, Western University, London, ON, Canada.
| | - Haris Smailovic
- Department of Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Medical Biophysics, Western University, London, ON, Canada
| | - Rebecca Sullivan
- Department of Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Medical Biophysics, Western University, London, ON, Canada
| | - Erik R Sistermans
- Department of Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
| | - John Butler
- Department of Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
| | - Hannah Jago
- Department of Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
| | - Michael Kovacs
- Department of Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Medical Biophysics, Western University, London, ON, Canada
| | - Gerald Wisenberg
- Department of Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Medical Biophysics, Western University, London, ON, Canada
- MyHealth Centre, Arva, ON, Canada
| | - Jonathan D Thiessen
- Department of Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Medical Biophysics, Western University, London, ON, Canada
| | - Frank S Prato
- Department of Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Medical Biophysics, Western University, London, ON, Canada
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Chau OW, El-Sherif O, Mouawad M, Sykes JM, Butler J, Biernaski H, deKemp R, Renaud J, Wisenberg G, Prato FS, Gaede S. Changes in myocardial blood flow in a canine model of left sided breast cancer radiotherapy. PLoS One 2023; 18:e0291854. [PMID: 37768966 PMCID: PMC10538714 DOI: 10.1371/journal.pone.0291854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 08/25/2023] [Indexed: 09/30/2023] Open
Abstract
BACKGROUND Left-sided breast cancer patients receiving adjuvant radiotherapy are at risk for coronary artery disease, and/or radiation mediated effects on the microvasculature. Previously our laboratory demonstrated in canines with hybrid 18FDG/PET a progressive global inflammatory response during the initial one year following treatment. In this study, the objective is to evaluate corresponding changes in perfusion, in the same cohort, where resting myocardial blood flow (MBF) was quantitatively measured. METHOD In five canines, Ammonia PET (13NH3) derived MBF was measured at baseline, 1-week, 1, 3, 6 and 12-months after cardiac external beam irradiation. MBF measurements were correlated with concurrent 18FDG uptake. Simultaneously MBF was measured using the dual bolus MRI method. RESULTS MBF was significantly increased at all time points, in comparison to baseline, except at 3-months. This was seen globally throughout the entire myocardium independent of the coronary artery territories. MBF showed a modest significant correlation with 18FDG activity for the entire myocardium (r = 0.51, p = 0.005) including the LAD (r = 0.49, p = 0.008) and LCX (r = 0.47, p = 0.013) coronary artery territories. CONCLUSION In this canine model of radiotherapy for left-sided breast cancer, resting MBF increases as early as 1-week and persists for up to one year except at 3-months. This pattern is similar to that of 18FDG uptake. A possible interpretation is that the increase in resting MBF is a response to myocardial inflammation.
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Affiliation(s)
- Oi-Wai Chau
- Department of Medical Biophysics, Western University, London, Ontario, Canada
- Department of Physics and Radiation Oncology, London Regional Cancer Program, London, Ontario, Canada
| | - Omar El-Sherif
- Mayo Clinic, Rochester, Minnesota, United States of America
| | - Matthew Mouawad
- Department of Physics and Radiation Oncology, London Regional Cancer Program, London, Ontario, Canada
| | - Jane M. Sykes
- Thames Valley Veterinary Services, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada
| | - John Butler
- Lawson Health Research Institute, London, Ontario, Canada
| | | | - Robert deKemp
- National Cardiac PET Centre, University of Ottawa Heart Institute, Ottawa, Ontario, Canada
| | - Jennifer Renaud
- Division of Cardiology, London Health Sciences Centre, London, Ontario, Canada
| | - Gerald Wisenberg
- Lawson Health Research Institute, London, Ontario, Canada
- Division of Cardiology, London Health Sciences Centre, London, Ontario, Canada
| | - Frank S. Prato
- Department of Medical Biophysics, Western University, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada
| | - Stewart Gaede
- Department of Medical Biophysics, Western University, London, Ontario, Canada
- Department of Physics and Radiation Oncology, London Regional Cancer Program, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada
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Chau OW, Islam A, Lock M, Yu E, Dinniwell R, Yaremko B, Brackstone M, Pavlosky W, Butler J, Biernaski H, Graf C, Wisenberg G, Prato FS, Gaede S. PET/MRI Assessment of Acute Cardiac Inflammation 1 Month After Left-Sided Breast Cancer Radiation Therapy. J Nucl Med Technol 2023; 51:133-139. [PMID: 37192822 DOI: 10.2967/jnmt.122.264960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 03/30/2023] [Indexed: 05/18/2023] Open
Abstract
Our purpose was to investigate the utility of 18F-FDG PET/MRI and serial blood work to detect early inflammatory responses and cardiac functionality changes at 1 mo after radiation therapy (RT) in patients with left-sided breast cancer. Methods: Fifteen left-sided breast cancer patients who enrolled in the RICT-BREAST study underwent cardiac PET/MRI at baseline and 1 mo after standard RT. Eleven patients received deep-inspiration breath-hold RT, whereas the others received free-breathing RT. A list-mode 18F-FDG PET scan with glucose suppression was acquired. Myocardial inflammation was quantified by the change in 18F-FDG SUVmean (based on body weight) and analyzed on the basis of the myocardial tissue associated with the left anterior descending, left circumflex, or right coronary artery territories. MRI assessments, including left ventricular functional and extracellular volumes (ECVs), were extracted from T1 (before and during a constant infusion of gadolinium) and cine images, respectively, acquired simultaneously during the PET acquisition. Cardiac injury and inflammation biomarker measurements of high-sensitivity troponin T, high-sensitivity C-reactive protein, and erythrocyte sedimentation rate were measured at the 1-mo follow-up and compared with preirradiation values. Results: At the 1-mo follow-up, a significant increase (10%) in myocardial SUVmean in left anterior descending segments (P = 0.04) and ECVs in slices at the apex (6%) and base (5%) was detected (P ≤ 0.02). Further, a significant reduction in left ventricular stroke volume (-7%) was seen (P < 0.02). No significant changes in any circulating biomarkers were seen at follow-up. Conclusion: Myocardial 18F-FDG uptake and functional MRI, including stroke volume and ECVs, were sensitive to changes at 1 mo after breast cancer RT, with findings suggesting an acute cardiac inflammatory response to RT.
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Affiliation(s)
- Oi Wai Chau
- London Regional Cancer Program, London, Ontario, Canada;
- Western University, London, Ontario, Canada
| | - Ali Islam
- Western University, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada; and
| | - Michael Lock
- London Regional Cancer Program, London, Ontario, Canada
- Western University, London, Ontario, Canada
- London Health Sciences Centre, London, Ontario, Canada
| | - Edward Yu
- London Regional Cancer Program, London, Ontario, Canada
- Western University, London, Ontario, Canada
- London Health Sciences Centre, London, Ontario, Canada
| | - Robert Dinniwell
- London Regional Cancer Program, London, Ontario, Canada
- Western University, London, Ontario, Canada
- London Health Sciences Centre, London, Ontario, Canada
| | - Brian Yaremko
- London Regional Cancer Program, London, Ontario, Canada
- Western University, London, Ontario, Canada
- London Health Sciences Centre, London, Ontario, Canada
| | - Muriel Brackstone
- Western University, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada; and
- London Health Sciences Centre, London, Ontario, Canada
| | - William Pavlosky
- Lawson Health Research Institute, London, Ontario, Canada; and
- London Health Sciences Centre, London, Ontario, Canada
| | - John Butler
- Lawson Health Research Institute, London, Ontario, Canada; and
| | | | - Chantelle Graf
- Lawson Health Research Institute, London, Ontario, Canada; and
| | - Gerald Wisenberg
- Western University, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada; and
- London Health Sciences Centre, London, Ontario, Canada
| | - Frank S Prato
- Western University, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada; and
| | - Stewart Gaede
- London Regional Cancer Program, London, Ontario, Canada
- Western University, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada; and
- London Health Sciences Centre, London, Ontario, Canada
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Dassanayake PSB, Prajapati R, Gelman N, Thompson RT, Prato FS, Goldhawk DE. Monocyte MRI Relaxation Rates Are Regulated by Extracellular Iron and Hepcidin. Int J Mol Sci 2023; 24:ijms24044036. [PMID: 36835448 PMCID: PMC9962677 DOI: 10.3390/ijms24044036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/08/2023] [Accepted: 02/09/2023] [Indexed: 02/19/2023] Open
Abstract
Many chronic inflammatory conditions are mediated by an increase in the number of monocytes in peripheral circulation, differentiation of monocytes to macrophages, and different macrophage subpopulations during pro- and anti-inflammatory stages of tissue injury. When hepcidin secretion is stimulated during inflammation, the iron export protein ferroportin is targeted for degradation on a limited number of cell types, including monocytes and macrophages. Such changes in monocyte iron metabolism raise the possibility of non-invasively tracking the activity of these immune cells using magnetic resonance imaging (MRI). We hypothesized that hepcidin-mediated changes in monocyte iron regulation influence both cellular iron content and MRI relaxation rates. In response to varying conditions of extracellular iron supplementation, ferroportin protein levels in human THP-1 monocytes decreased two- to eightfold, consistent with paracrine/autocrine regulation of iron export. Following hepcidin treatment, ferroportin protein levels further decreased two- to fourfold. This was accompanied by an approximately twofold increase in total transverse relaxation rate, R2*, compared to non-supplemented cells. A positive correlation between total cellular iron content and R2* improved from moderate to strong in the presence of hepcidin. These findings suggest that hepcidin-mediated changes detected in monocytes using MRI could be valuable for in vivo cell tracking of inflammatory responses.
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Affiliation(s)
- Praveen S. B. Dassanayake
- Imaging Program, Lawson Health Research Institute, London, ON N6A 4V2, Canada
- Medical Biophysics, Western University, London, ON N6A 5C1, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, ON N6A 5C1, Canada
| | - Rahil Prajapati
- Imaging Program, Lawson Health Research Institute, London, ON N6A 4V2, Canada
| | - Neil Gelman
- Imaging Program, Lawson Health Research Institute, London, ON N6A 4V2, Canada
- Medical Biophysics, Western University, London, ON N6A 5C1, Canada
| | - R. Terry Thompson
- Imaging Program, Lawson Health Research Institute, London, ON N6A 4V2, Canada
- Medical Biophysics, Western University, London, ON N6A 5C1, Canada
| | - Frank S. Prato
- Imaging Program, Lawson Health Research Institute, London, ON N6A 4V2, Canada
- Medical Biophysics, Western University, London, ON N6A 5C1, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, ON N6A 5C1, Canada
| | - Donna E. Goldhawk
- Imaging Program, Lawson Health Research Institute, London, ON N6A 4V2, Canada
- Medical Biophysics, Western University, London, ON N6A 5C1, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, ON N6A 5C1, Canada
- Correspondence:
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Ottoy J, Ozzoude M, Zukotynski K, Kang MS, Adamo S, Scott C, Ramirez J, Swardfager W, Lam B, Bhan A, Mojiri P, Kiss A, Strother S, Bocti C, Borrie M, Chertkow H, Frayne R, Hsiung R, Laforce RJ, Noseworthy MD, Prato FS, Sahlas DJ, Smith EE, Kuo PH, Chad JA, Pasternak O, Sossi V, Thiel A, Soucy JP, Tardif JC, Black SE, Goubran M. Amyloid-PET of the white matter: Relationship to free water, fiber integrity, and cognition in patients with dementia and small vessel disease. J Cereb Blood Flow Metab 2023; 43:921-936. [PMID: 36695071 DOI: 10.1177/0271678x231152001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
White matter (WM) injury is frequently observed along with dementia. Positron emission tomography with amyloid-ligands (Aβ-PET) recently gained interest for detecting WM injury. Yet, little is understood about the origin of the altered Aβ-PET signal in WM regions. Here, we investigated the relative contributions of diffusion MRI-based microstructural alterations, including free water and tissue-specific properties, to Aβ-PET in WM and to cognition. We included a unique cohort of 115 participants covering the spectrum of low-to-severe white matter hyperintensity (WMH) burden and cognitively normal to dementia. We applied a bi-tensor diffusion-MRI model that differentiates between (i) the extracellular WM compartment (represented via free water), and (ii) the fiber-specific compartment (via free water-adjusted fractional anisotropy [FA]). We observed that, in regions of WMH, a decrease in Aβ-PET related most closely to higher free water and higher WMH volume. In contrast, in normal-appearing WM, an increase in Aβ-PET related more closely to higher cortical Aβ (together with lower free water-adjusted FA). In relation to cognitive impairment, we observed a closer relationship with higher free water than with either free water-adjusted FA or WM PET. Our findings support free water and Aβ-PET as markers of WM abnormalities in patients with mixed dementia, and contribute to a better understanding of processes giving rise to the WM PET signal.
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Affiliation(s)
- Julie Ottoy
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada
| | - Miracle Ozzoude
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada
| | - Katherine Zukotynski
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada.,Departments of Medicine and Radiology, McMaster University, Hamilton, ON, Canada.,Department of Medical Imaging, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada.,Department of Radiology, University of British Columbia, Vancouver, BC, Canada
| | - Min Su Kang
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada.,Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Sabrina Adamo
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada
| | - Christopher Scott
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada
| | - Joel Ramirez
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada
| | - Walter Swardfager
- Department of Pharmacology & Toxicology, University of Toronto, Toronto, ON, Canada
| | - Benjamin Lam
- Department of Medicine (Division of Neurology), Dr. Sandra Black Centre for Brain Resilience and Recovery, Hurvitz Brain Sciences Research Program, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada
| | - Aparna Bhan
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada
| | - Parisa Mojiri
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada
| | - Alex Kiss
- Department of Research Design and Biostatistics, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada
| | - Stephen Strother
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada.,The Rotman Research Institute Baycrest, University of Toronto, Toronto, ON, Canada
| | - Christian Bocti
- Service de Neurologie, Département de Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Michael Borrie
- Lawson Health Research Institute, Western University, London, ON, Canada
| | - Howard Chertkow
- Jewish General Hospital and Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Richard Frayne
- Departments of Radiology and Clinical Neuroscience, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Robin Hsiung
- Physics and Astronomy Department and DM Center for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Robert Jr Laforce
- Clinique Interdisciplinaire de Mémoire, Département des Sciences Neurologiques, Université Laval, Québec, QC, Canada
| | - Michael D Noseworthy
- Departments of Medicine and Radiology, McMaster University, Hamilton, ON, Canada.,Department of Electrical and Computer Engineering, McMaster University, Hamilton, ON, Canada
| | - Frank S Prato
- Lawson Health Research Institute, Western University, London, ON, Canada
| | | | - Eric E Smith
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Phillip H Kuo
- Department of Medical Imaging, Medicine, and Biomedical Engineering, University of Arizona, Tucson, AZ, USA
| | - Jordan A Chad
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada.,The Rotman Research Institute Baycrest, University of Toronto, Toronto, ON, Canada
| | - Ofer Pasternak
- Departments of Psychiatry and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, USA
| | - Vesna Sossi
- Physics and Astronomy Department and DM Center for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Alexander Thiel
- Jewish General Hospital and Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Jean-Paul Soucy
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | | | - Sandra E Black
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada.,Department of Medicine (Division of Neurology), Dr. Sandra Black Centre for Brain Resilience and Recovery, Hurvitz Brain Sciences Research Program, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada
| | - Maged Goubran
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada.,Physical Sciences Platform, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
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9
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Cokic I, Chan SF, Guan X, Nair AR, Yang HJ, Liu T, Chen Y, Hernando D, Sykes J, Tang R, Butler J, Dohnalkova A, Kovarik L, Finney R, Kali A, Sharif B, Bouchard LS, Gupta R, Krishnam MS, Vora K, Tamarappoo B, Howarth AG, Kumar A, Francis J, Reeder SB, Wood JC, Prato FS, Dharmakumar R. Intramyocardial hemorrhage drives fatty degeneration of infarcted myocardium. Nat Commun 2022; 13:6394. [PMID: 36302906 PMCID: PMC9613644 DOI: 10.1038/s41467-022-33776-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 10/03/2022] [Indexed: 01/24/2023] Open
Abstract
Sudden blockage of arteries supplying the heart muscle contributes to millions of heart attacks (myocardial infarction, MI) around the world. Although re-opening these arteries (reperfusion) saves MI patients from immediate death, approximately 50% of these patients go on to develop chronic heart failure (CHF) and die within a 5-year period; however, why some patients accelerate towards CHF while others do not remains unclear. Here we show, using large animal models of reperfused MI, that intramyocardial hemorrhage - the most damaging form of reperfusion injury (evident in nearly 40% of reperfused ST-elevation MI patients) - drives delayed infarct healing and is centrally responsible for continuous fatty degeneration of the infarcted myocardium contributing to adverse remodeling of the heart. Specifically, we show that the fatty degeneration of the hemorrhagic MI zone stems from iron-induced macrophage activation, lipid peroxidation, foam cell formation, ceroid production, foam cell apoptosis and iron recycling. We also demonstrate that timely reduction of iron within the hemorrhagic MI zone reduces fatty infiltration and directs the heart towards favorable remodeling. Collectively, our findings elucidate why some, but not all, MIs are destined to CHF and help define a potential therapeutic strategy to mitigate post-MI CHF independent of MI size.
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Affiliation(s)
- Ivan Cokic
- Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Shing Fai Chan
- Krannert Cardiovascular Research Center, Indiana University School of Medicine/IU Health Cardiovascular Institute, Indianapolis, IN, USA
| | - Xingmin Guan
- Krannert Cardiovascular Research Center, Indiana University School of Medicine/IU Health Cardiovascular Institute, Indianapolis, IN, USA
| | - Anand R Nair
- Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | | | - Ting Liu
- Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Yinyin Chen
- Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | | | - Jane Sykes
- Lawson Health Research Institute, University of Western Ontario, London, ON, Canada
| | - Richard Tang
- Krannert Cardiovascular Research Center, Indiana University School of Medicine/IU Health Cardiovascular Institute, Indianapolis, IN, USA
| | - John Butler
- Lawson Health Research Institute, University of Western Ontario, London, ON, Canada
| | | | - Libor Kovarik
- Pacific Northwest National Laboratory, Richland, WA, USA
| | | | - Avinash Kali
- Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Behzad Sharif
- Krannert Cardiovascular Research Center, Indiana University School of Medicine/IU Health Cardiovascular Institute, Indianapolis, IN, USA
| | | | | | | | - Keyur Vora
- Krannert Cardiovascular Research Center, Indiana University School of Medicine/IU Health Cardiovascular Institute, Indianapolis, IN, USA
| | - Balaji Tamarappoo
- Krannert Cardiovascular Research Center, Indiana University School of Medicine/IU Health Cardiovascular Institute, Indianapolis, IN, USA
| | | | - Andreas Kumar
- Northern Ontario School of Medicine, Sudbury, ON, Canada
| | | | | | - John C Wood
- University of Southern California, Los Angeles, CA, USA
| | - Frank S Prato
- Lawson Health Research Institute, University of Western Ontario, London, ON, Canada
| | - Rohan Dharmakumar
- Krannert Cardiovascular Research Center, Indiana University School of Medicine/IU Health Cardiovascular Institute, Indianapolis, IN, USA.
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10
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Ottoy J, Ozzoude M, Zukotynski K, Adamo S, Scott C, Gaudet V, Ramirez J, Swardfager W, Cogo-Moreira H, Lam B, Bhan A, Mojiri P, Kang MS, Rabin JS, Kiss A, Strother S, Bocti C, Borrie M, Chertkow H, Frayne R, Hsiung R, Laforce RJ, Noseworthy MD, Prato FS, Sahlas DJ, Smith EE, Kuo PH, Sossi V, Thiel A, Soucy JP, Tardif JC, Black SE, Goubran M. Vascular burden and cognition: Mediating roles of neurodegeneration and amyloid PET. Alzheimers Dement 2022; 19:1503-1517. [PMID: 36047604 DOI: 10.1002/alz.12750] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 06/06/2022] [Accepted: 06/10/2022] [Indexed: 11/06/2022]
Abstract
It remains unclear to what extent cerebrovascular burden relates to amyloid beta (Aβ) deposition, neurodegeneration, and cognitive dysfunction in mixed disease populations with small vessel disease and Alzheimer's disease (AD) pathology. In 120 subjects, we investigated the association of vascular burden (white matter hyperintensity [WMH] volumes) with cognition. Using mediation analyses, we tested the indirect effects of WMH on cognition via Aβ deposition (18 F-AV45 positron emission tomography [PET]) and neurodegeneration (cortical thickness or 18 F fluorodeoxyglucose PET) in AD signature regions. We observed that increased total WMH volume was associated with poorer performance in all tested cognitive domains, with the strongest effects observed for semantic fluency. These relationships were mediated mainly via cortical thinning, particularly of the temporal lobe, and to a lesser extent serially mediated via Aβ and cortical thinning of AD signature regions. WMH volumes differentially impacted cognition depending on lobar location and Aβ status. In summary, our study suggests mainly an amyloid-independent pathway in which vascular burden affects cognitive function via localized neurodegeneration. HIGHLIGHTS: Alzheimer's disease often co-exists with vascular pathology. We studied a unique cohort enriched for high white matter hyperintensities (WMH). High WMH related to cognitive impairment of semantic fluency and executive function. This relationship was mediated via temporo-parietal atrophy rather than metabolism. This relationship was, to lesser extent, serially mediated via amyloid beta and atrophy.
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Affiliation(s)
- Julie Ottoy
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Miracle Ozzoude
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Katherine Zukotynski
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada.,Departments of Medicine and Radiology, McMaster University, Hamilton, Ontario, Canada.,Department of Medical Imaging, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada.,Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Sabrina Adamo
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Christopher Scott
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Vincent Gaudet
- Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, Ontario, Canada
| | - Joel Ramirez
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Walter Swardfager
- Department of Pharmacology & Toxicology, University of Toronto, Toronto, Ontario, Canada
| | - Hugo Cogo-Moreira
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada.,Department of Education, ICT and Learning, Østfold University College, Halden, Norway
| | - Benjamin Lam
- Department of Medicine (Division of Neurology), University of Toronto, Toronto, Ontario, Canada
| | - Aparna Bhan
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Parisa Mojiri
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Min Su Kang
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada.,Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada.,Physical Sciences Platform, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Jennifer S Rabin
- Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, Ontario, Canada.,Harquail Centre for Neuromodulation, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.,Division of Neurology, Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.,Rehabilitation Sciences Institute, University of Toronto, Toronto, Ontario, Canada
| | - Alex Kiss
- Department of Research Design and Biostatistics, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Stephen Strother
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.,The Rotman Research Institute Baycrest, University of Toronto, Toronto, Ontario, Canada
| | - Christian Bocti
- Département de Médecine, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Michael Borrie
- Lawson Health Research Institute, Western University, London, Ontario, Canada
| | - Howard Chertkow
- Jewish General Hospital and Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Richard Frayne
- Departments of Radiology and Clinical Neuroscience, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Robin Hsiung
- Physics and Astronomy Department and DM Center for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Robert Jr Laforce
- Clinique Interdisciplinaire de Mémoire, Département des Sciences Neurologiques, Université Laval, Quebec City, Quebec, Canada
| | - Michael D Noseworthy
- Department of Electrical and Computer Engineering, McMaster University, Hamilton, Ontario, Canada
| | - Frank S Prato
- Lawson Health Research Institute, Western University, London, Ontario, Canada
| | | | - Eric E Smith
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Phillip H Kuo
- Department of Medical Imaging, Medicine, and Biomedical Engineering, University of Arizona, Tucson, Arizona, USA
| | - Vesna Sossi
- Physics and Astronomy Department and DM Center for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Alexander Thiel
- Jewish General Hospital and Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Jean-Paul Soucy
- Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Jean-Claude Tardif
- Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada
| | - Sandra E Black
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada.,Department of Medicine (Division of Neurology), University of Toronto, Toronto, Ontario, Canada.,Dr. Sandra Black Centre for Brain Resilience and Recovery, Hurvitz Brain Sciences Research Program, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - Maged Goubran
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada.,Physical Sciences Platform, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
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11
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Farrag NA, Thornhill RE, Prato FS, Skanes AC, Sullivan R, Sebben D, Butler J, Sykes J, Wilk B, Ukwatta E. Assessment of left atrial fibrosis progression in canines following rapid ventricular pacing using 3D late gadolinium enhanced CMR images. PLoS One 2022; 17:e0269592. [PMID: 35802680 PMCID: PMC9269919 DOI: 10.1371/journal.pone.0269592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 05/24/2022] [Indexed: 11/30/2022] Open
Abstract
Background Atrial fibrillation (AF) is associated with extracellular matrix (ECM) remodelling and often coexists with myocardial fibrosis (MF); however, the causality of these conditions is not well established. Objective We aim to corroborate AF to MF causality by quantifying left atrial (LA) fibrosis in cardiac magnetic resonance (CMR) images after persistent rapid ventricular pacing and subsequent AF using a canine model and histopathological validation. Methods Twelve canines (9 experimental, 3 control) underwent baseline 3D LGE-CMR imaging at 3T followed by insertion of a pacing device and 5 weeks of rapid ventricular pacing to induce AF (experimental) or no pacing (control). Following the 5 weeks, pacing devices were removed to permit CMR imaging followed by excision of the hearts and histopathological imaging. LA myocardial segmentation was performed manually at baseline and post-pacing to permit volumetric %MF quantification using the image intensity ratio (IIR) technique, wherein fibrosis was defined as pixels > mean LA myocardium intensity + 2SD. Results Volumetric %MF increased by an average of 2.11 ± 0.88% post-pacing in 7 of 9 experimental dogs. While there was a significant difference between paired %MF measurements from baseline to post-pacing in experimental dogs (P = 0.019), there was no significant change in control dogs (P = 0.019 and P = 0.5, Wilcoxon signed rank tests). The median %MF for paced animals was significantly greater than that of non-paced dogs at the 5-week post-insertion time point (P = 0.009, Mann Whitney U test). Histopathological imaging yielded an average %MF of 19.42 ± 4.80% (mean ± SD) for paced dogs compared to 1.85% in one control dog. Conclusion Persistent rapid ventricular pacing and subsequent AF leads to an increase in LA fibrosis volumes measured by the IIR technique; however, quantification is limited by inherent image acquisition parameters and observer variability.
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Affiliation(s)
- Nadia A. Farrag
- Department of Systems & Computer Engineering, Carleton University, Ottawa, ON, Canada
- * E-mail:
| | - Rebecca E. Thornhill
- Department of Systems & Computer Engineering, Carleton University, Ottawa, ON, Canada
- Department of Radiology, University of Ottawa, Ottawa, ON, Canada
| | - Frank S. Prato
- Department of Medical Imaging and Medical Biophysics, University of Western Ontario, London, ON, Canada
- Lawson Health Research Institute, London, ON, Canada
| | - Allan C. Skanes
- Department of Medicine, University of Western Ontario, London, ON, Canada
| | - Rebecca Sullivan
- Department of Medical Imaging and Medical Biophysics, University of Western Ontario, London, ON, Canada
| | - David Sebben
- School of Engineering, University of Guelph, Guelph, ON, Canada
| | - John Butler
- Lawson Health Research Institute, London, ON, Canada
| | - Jane Sykes
- Lawson Health Research Institute, London, ON, Canada
| | - Benjamin Wilk
- Department of Medical Imaging and Medical Biophysics, University of Western Ontario, London, ON, Canada
- Lawson Health Research Institute, London, ON, Canada
| | - Eranga Ukwatta
- Department of Systems & Computer Engineering, Carleton University, Ottawa, ON, Canada
- School of Engineering, University of Guelph, Guelph, ON, Canada
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12
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Smailovic H, Wilk B, Wisenberg G, Sykes J, Butler J, Hicks J, Thiessen JD, Prato FS. Simultaneous measurements of myocardial glucose metabolism and extracellular volumes with hybrid PET/MRI using concurrent injections of Gd-DTPA and [ 18F]FDG. J Nucl Cardiol 2022; 29:1304-1314. [PMID: 33502694 DOI: 10.1007/s12350-020-02486-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 11/28/2020] [Indexed: 12/22/2022]
Abstract
BACKGROUND The aims of this study were to investigate the application of a constant infusion (CI) to mitigate the issue of constantly changing Gd-DTPA contrast levels in a bolus injection for extracellular volume (ECV) measurements by (a) comparing a CI alone to a bolus alone and a bolus followed by CI in healthy myocardium, (b) evaluating the impact of glucose suppression using heparin on ECV. METHODS Five healthy canine subjects were imaged to compare three different protocols for injecting Gd-DTPA and FDG: bolus alone, CI alone, bolus followed by CI. Suppression of myocardial glucose uptake was induced using a continuous infusion of 20% lipid at a rate of 0.25 mL·min-1·kg-1 as well as 2000 units of intravenous heparin injected 20 minutes prior to FDG/Gd-DTPA injection. RESULTS There was no significant effect on ECV measurement when heparin was used for glucose suppression at equilibrium irrespective of infusion protocol). Measurements of ECV in myocardium, regardless of infusion protocol showed no significant difference at all time points (P = 0.21) prior to washout. CONCLUSIONS The suppression of myocardial uptake of [18F]FDG with heparin did not alter the determination of myocardial ECV though a larger sample size may show differences. Further, the infusion protocol (bolus or constant infusion) had no effect on the calculated ECV.
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Affiliation(s)
- H Smailovic
- Department of Medical Imaging, Western University, London, Canada
- Lawson Health Research Institute, London, Canada
| | - B Wilk
- Department of Medical Imaging, Western University, London, Canada.
- Lawson Health Research Institute, London, Canada.
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Canada.
- Department of Medical Biophysics, Western University, London, Canada.
| | | | - J Sykes
- Lawson Health Research Institute, London, Canada
| | - J Butler
- Lawson Health Research Institute, London, Canada
| | - J Hicks
- Lawson Health Research Institute, London, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Canada
| | - J D Thiessen
- Department of Medical Imaging, Western University, London, Canada
- Lawson Health Research Institute, London, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Canada
- Department of Medical Biophysics, Western University, London, Canada
| | - F S Prato
- Department of Medical Imaging, Western University, London, Canada
- Lawson Health Research Institute, London, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Canada
- Department of Medical Biophysics, Western University, London, Canada
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13
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Wilk B, Smailovic H, Wisenberg G, Sykes J, Butler J, Kovacs M, Thiessen JD, Prato FS. Tracking the progress of inflammation with PET/MRI in a canine model of myocardial infarction. J Nucl Cardiol 2022; 29:1315-1325. [PMID: 33462785 DOI: 10.1007/s12350-020-02487-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 11/28/2020] [Indexed: 11/25/2022]
Abstract
BACKGROUND Following myocardial infarction, tissue undergoes pathophysiological changes involving inflammation and scar tissue formation. However, little is known about the pathophysiology and prognostic significance of any corresponding changes in remote myocardium. The aim of this study was to investigate the potential application of a combined constant infusion of 18F-FDG and Gd-DTPA to quantitate inflammation and extracellular volume (ECV) from 3 to 40 days after myocardial infarction. METHODS Eight canine subjects were imaged at multiple time points following induction of an MI with a 60-minute concurrent constant infusion of Gd-DTPA and 18F-FDG using a hybrid PET/MRI scanner. RESULTS There was a significant increase in ECV in remote myocardium on day 14 post-MI (P = .034) and day 21 (P = .021) compared to the baseline. ECV was significantly elevated in the infarcted myocardium compared to remote myocardium at all time points post-MI (days 3, 7, 14, 21, and 40) (P < .001) while glucose uptake was also increased within the infarct on days 3, 7, 14, and 21 but not 40. CONCLUSIONS The significant increase in ECV in remote tissue may be due to an ongoing inflammatory process in the early weeks post-infarct.
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Affiliation(s)
- B Wilk
- Lawson Health Research Institute, London, Canada.
- Department of Medical Biophysics, Western University, London, Canada.
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Canada.
| | - H Smailovic
- Lawson Health Research Institute, London, Canada
- Department of Medical Imaging, Western University, London, Canada
| | - G Wisenberg
- Lawson Health Research Institute, London, Canada
- MyHealth Centre, Arva, Canada
| | - J Sykes
- Lawson Health Research Institute, London, Canada
| | - J Butler
- Lawson Health Research Institute, London, Canada
| | - M Kovacs
- Lawson Health Research Institute, London, Canada
- Department of Medical Biophysics, Western University, London, Canada
- Department of Medical Imaging, Western University, London, Canada
| | - J D Thiessen
- Lawson Health Research Institute, London, Canada
- Department of Medical Biophysics, Western University, London, Canada
- Department of Medical Imaging, Western University, London, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Canada
| | - F S Prato
- Lawson Health Research Institute, London, Canada
- Department of Medical Biophysics, Western University, London, Canada
- Department of Medical Imaging, Western University, London, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Canada
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14
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Chau O, Islam A, Yu E, Qu M, Butler J, Biernaski H, Sun A, Bissonnette JP, MacDonald A, Graf C, So A, Wisenberg G, Lee T, Prato FS, Gaede S. Multi-Modality Imaging Assessment of the Heart Before and After Stage III Non-Small Cell Lung Cancer Radiotherapy. Adv Radiat Oncol 2022; 7:100927. [PMID: 35434423 PMCID: PMC9006649 DOI: 10.1016/j.adro.2022.100927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 02/07/2022] [Indexed: 11/26/2022] Open
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15
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Liu T, Howarth AG, Chen Y, Nair AR, Yang HJ, Ren D, Tang R, Sykes J, Kovacs MS, Dey D, Slomka P, Wood JC, Finney R, Zeng M, Prato FS, Francis J, Berman DS, Shah PK, Kumar A, Dharmakumar R. Intramyocardial Hemorrhage and the "Wave Front" of Reperfusion Injury Compromising Myocardial Salvage. J Am Coll Cardiol 2022; 79:35-48. [PMID: 34991787 DOI: 10.1016/j.jacc.2021.10.034] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 10/04/2021] [Accepted: 10/12/2021] [Indexed: 01/29/2023]
Abstract
BACKGROUND Reperfusion therapy for acute myocardial infarction (MI) is lifesaving. However, the benefit of reperfusion therapy can be paradoxically diminished by reperfusion injury, which can increase MI size. OBJECTIVES Hemorrhage is known to occur in reperfused MIs, but whether hemorrhage plays a role in reperfusion-mediated MI expansion is not known. METHODS We studied cardiac troponin kinetics (cTn) of ST-segment elevation MI patients (n = 70) classified by cardiovascular magnetic resonance to be hemorrhagic (70%) or nonhemorrhagic following primary percutaneous coronary intervention. To isolate the effects of hemorrhage from ischemic burden, we performed controlled canine studies (n = 25), and serially followed both cTn and MI size with time-lapse imaging. RESULTS CTn was not different before reperfusion; however, an increase in cTn following primary percutaneous coronary intervention peaked earlier (12 hours vs 24 hours; P < 0.05) and was significantly higher in patients with hemorrhage (P < 0.01). In hemorrhagic animals, reperfusion led to rapid expansion of myocardial necrosis culminating in epicardial involvement, which was not present in nonhemorrhagic cases (P < 0.001). MI size and salvage were not different at 1 hour postreperfusion in animals with and without hemorrhage (P = 0.65). However, within 72 hours of reperfusion, a 4-fold greater loss in salvageable myocardium was evident in hemorrhagic MIs (P < 0.001). This paralleled observations in patients with larger MIs occurring in hemorrhagic cases (P < 0.01). CONCLUSIONS Myocardial hemorrhage is a determinant of MI size. It drives MI expansion after reperfusion and compromises myocardial salvage. This introduces a clinical role of hemorrhage in acute care management, risk assessment, and future therapeutics.
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Affiliation(s)
- Ting Liu
- Cedars-Sinai Medical Center, Los Angeles, California, USA; Department of Radiology, the First Affiliated Hospital of China Medical University, Shenyang, China
| | - Andrew G Howarth
- Cedars-Sinai Medical Center, Los Angeles, California, USA; University of Calgary, Calgary, Alberta, Canada
| | - Yinyin Chen
- Cedars-Sinai Medical Center, Los Angeles, California, USA; Zhongshan Hospital, Fudan University and Shanghai Institute of Medical Imaging, Shanghai, China
| | - Anand R Nair
- Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Hsin-Jung Yang
- Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Daoyuan Ren
- Zhongshan Hospital, Fudan University and Shanghai Institute of Medical Imaging, Shanghai, China
| | - Richard Tang
- Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Jane Sykes
- Lawson Research Institute, University of Western Ontario, London, Ontario, Canada
| | - Michael S Kovacs
- Lawson Research Institute, University of Western Ontario, London, Ontario, Canada
| | - Damini Dey
- Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Piotr Slomka
- Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - John C Wood
- University of Southern California, Los Angeles, California, USA
| | | | - Mengsu Zeng
- Zhongshan Hospital, Fudan University and Shanghai Institute of Medical Imaging, Shanghai, China
| | - Frank S Prato
- Lawson Research Institute, University of Western Ontario, London, Ontario, Canada
| | | | | | | | - Andreas Kumar
- Northern Ontario School of Medicine, Sudbury, Ontario, Canada
| | - Rohan Dharmakumar
- Cedars-Sinai Medical Center, Los Angeles, California, USA; Krannert Cardiovascular Research Center, Indiana University School of Medicine/IU Health Cardiovascular Institute, Indianapolis, Indiana, USA.
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16
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Ottoy J, Ozzoude M, Zukotynski K, Adamo SM, Scott CJM, Gaudet V, Ramirez J, Swardfager W, Lam B, Bhan A, Kiss A, Strother SC, Bocti C, Borrie M, Chertkow H, Frayne R, Hsiung GR, Laforce R, Noseworthy MD, Prato FS, Sahlas DJ, Smith EE, Sossi V, Thiel A, Soucy J, Tardif J, Goubran M, Black SE. Amyloid‐independent vascular contributions to cortical atrophy and cognition in a multi‐center mixed cohort with low to severe small vessel disease. Alzheimers Dement 2021. [DOI: 10.1002/alz.056326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Julie Ottoy
- LC Campbell Cognitive Neurology Research Unit, Sunnybrook Research Institute, University of Toronto Toronto ON Canada
| | - Miracle Ozzoude
- LC Campbell Cognitive Neurology Research Unit, Sunnybrook Research Institute, University of Toronto Toronto ON Canada
| | - Katherine Zukotynski
- Departments of Medicine and Radiology, McMaster University Hamilton ON Canada
- LC Campbell Cognitive Neurology Research Unit, Sunnybrook Research Institute Toronto ON Canada
| | - Sabrina M. Adamo
- LC Campbell Cognitive Neurology Research Unit, Sunnybrook Research Institute, University of Toronto Toronto ON Canada
| | - Christopher J. M. Scott
- LC Campbell Cognitive Neurology Research Unit, Sunnybrook Research Institute Toronto ON Canada
| | - Vincent Gaudet
- Department of Electrical and Computer Engineering, University of Waterloo Waterloo ON Canada
| | - Joel Ramirez
- LC Campbell Cognitive Neurology Research Unit, Sunnybrook Research Institute, University of Toronto Toronto ON Canada
| | - Walter Swardfager
- Department of Pharmacology & Toxicology, University of Toronto Toronto ON Canada
| | - Benjamin Lam
- LC Campbell Cognitive Neurology Research Unit, Sunnybrook Research Institute Toronto ON Canada
| | - Aparna Bhan
- LC Campbell Cognitive Neurology Research Unit, Sunnybrook Research Institute Toronto ON Canada
| | - Alex Kiss
- Department of Research Design and Biostatistics, Sunnybrook Research Institute, University of Toronto Toronto ON Canada
| | | | - Christian Bocti
- Département de Médecine, Université de Sherbrooke Sherbrooke QC Canada
| | - Michael Borrie
- Lawson Health Research Institute, Western University London ON Canada
| | | | - Richard Frayne
- Departments of Radiology and Clinical Neuroscience, University of Calgary Calgary AB Canada
| | - Ging‐Yuek Robin Hsiung
- Djavad Mowafaghian Centre for Brain Health, University of British Colombia Vancouver BC Canada
| | - Robert Laforce
- Clinique Interdisciplinaire de Mémoire, CHU de Québec/Université Laval/Hôpital de l’Enfant‐Jésus Quebec City QC Canada
| | - Michael D. Noseworthy
- Department of Electrical and Computer Engineering, McMaster University Hamilton ON Canada
| | - Frank S. Prato
- Lawson Health Research Institute, Western University London ON Canada
| | | | - Eric E. Smith
- Hotchkiss Brain Institute, University of Calgary Calgary AB Canada
| | - Vesna Sossi
- Physics and Astronomy Department and DM Center for Brain Health, University of British Columbia Vancouver BC Canada
| | - Alexander Thiel
- Jewish General Hospital, McGill University Montreal QC Canada
| | - Jean‐Paul Soucy
- Montreal Neurological Institute, McGill University Montreal QC Canada
| | | | - Maged Goubran
- LC Campbell Cognitive Neurology Research Unit, Sunnybrook Research Institute, University of Toronto Toronto ON Canada
| | - Sandra E. Black
- LC Campbell Cognitive Neurology Research Unit, Sunnybrook Research Institute, University of Toronto Toronto ON Canada
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17
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Prato FS, Wisenberg G. Reproducibility and repeatability of assessment of myocardial light chain amyloidosis burden using 18F-florbetapir PET/CT. J Nucl Cardiol 2021; 28:2011-2013. [PMID: 31797317 DOI: 10.1007/s12350-019-01971-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 11/18/2019] [Indexed: 11/26/2022]
Affiliation(s)
- Frank S Prato
- Departments of Medical Biophysics, Medical Imaging and Physics and Astronomy, Western University, London, ON, Canada.
- Lawson Imaging, Lawson Health Research Institute, London, ON, Canada.
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18
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Guan X, Chen Y, Yang HJ, Zhang X, Ren D, Sykes J, Butler J, Han H, Zeng M, Prato FS, Dharmakumar R. Assessment of intramyocardial hemorrhage with dark-blood T2*-weighted cardiovascular magnetic resonance. J Cardiovasc Magn Reson 2021; 23:88. [PMID: 34261494 PMCID: PMC8281666 DOI: 10.1186/s12968-021-00787-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 06/08/2021] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Intramyocardial hemorrhage (IMH) within myocardial infarction (MI) is associated with major adverse cardiovascular events. Bright-blood T2*-based cardiovascular magnetic resonance (CMR) has emerged as the reference standard for non-invasive IMH detection. Despite this, the dark-blood T2*-based CMR is becoming interchangeably used with bright-blood T2*-weighted CMR in both clinical and preclinical settings for IMH detection. To date however, the relative merits of dark-blood T2*-weighted with respect to bright-blood T2*-weighted CMR for IMH characterization has not been studied. We investigated the diagnostic capacity of dark-blood T2*-weighted CMR against bright-blood T2*-weighted CMR for IMH characterization in clinical and preclinical settings. MATERIALS AND METHODS Hemorrhagic MI patients (n = 20) and canines (n = 11) were imaged in the acute and chronic phases at 1.5 and 3 T with dark- and bright-blood T2*-weighted CMR. Imaging characteristics (Relative signal-to-noise (SNR), Relative contrast-to-noise (CNR), IMH Extent) and diagnostic performance (sensitivity, specificity, accuracy, area-under-the-curve, and inter-observer variability) of dark-blood T2*-weighted CMR for IMH characterization were assessed relative to bright-blood T2*-weighted CMR. RESULTS At both clinical and preclinical settings, compared to bright-blood T2*-weighted CMR, dark-blood T2*-weighted images had significantly lower SNR, CNR and reduced IMH extent (all p < 0.05). Dark-blood T2*-weighted CMR also demonstrated weaker sensitivity, specificity, accuracy, and inter-observer variability compared to bright-blood T2*-weighted CMR (all p < 0.05). These observations were consistent across infarct age and imaging field strengths. CONCLUSION While IMH can be visible on dark-blood T2*-weighted CMR, the overall conspicuity of IMH is significantly reduced compared to that observed in bright-blood T2*-weighted images, across infarct age in clinical and preclinical settings at 1.5 and 3 T. Hence, bright-blood T2*-weighted CMR would be preferable for clinical use since dark-blood T2*-weighted CMR carries the potential to misclassify hemorrhagic MIs as non-hemorrhagic MIs.
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Affiliation(s)
- Xingmin Guan
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Biomedical Imaging Research Institute, PACT Bldg - Suite 400, 8700 Beverly Blvd, Los Angeles, CA, USA
- University of California, Los Angeles, CA, USA
| | - Yinyin Chen
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Biomedical Imaging Research Institute, PACT Bldg - Suite 400, 8700 Beverly Blvd, Los Angeles, CA, USA
- Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, China
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Hsin-Jung Yang
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Biomedical Imaging Research Institute, PACT Bldg - Suite 400, 8700 Beverly Blvd, Los Angeles, CA, USA
| | - Xinheng Zhang
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Biomedical Imaging Research Institute, PACT Bldg - Suite 400, 8700 Beverly Blvd, Los Angeles, CA, USA
- University of California, Los Angeles, CA, USA
| | - Daoyuan Ren
- Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, China
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Jane Sykes
- Lawson Health Research Institute, University of Western Ontario, London, ON, Canada
| | - John Butler
- Lawson Health Research Institute, University of Western Ontario, London, ON, Canada
| | - Hui Han
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Biomedical Imaging Research Institute, PACT Bldg - Suite 400, 8700 Beverly Blvd, Los Angeles, CA, USA
| | - Mengsu Zeng
- Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, China
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Frank S Prato
- Lawson Health Research Institute, University of Western Ontario, London, ON, Canada
| | - Rohan Dharmakumar
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Biomedical Imaging Research Institute, PACT Bldg - Suite 400, 8700 Beverly Blvd, Los Angeles, CA, USA.
- University of California, Los Angeles, CA, USA.
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19
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Mouawad M, Lailey O, Poulsen P, O'Neil M, Brackstone M, Lock M, Yaremko B, Shmuilovich O, Kornecki A, Ben Nachum I, Muscedere G, Lynn K, Karnas S, Prato FS, Thompson RT, Gaede S. Intrafraction motion monitoring to determine PTV margins in early stage breast cancer patients receiving neoadjuvant partial breast SABR. Radiother Oncol 2021; 158:276-284. [PMID: 33636230 DOI: 10.1016/j.radonc.2021.02.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Revised: 02/10/2021] [Accepted: 02/13/2021] [Indexed: 10/22/2022]
Abstract
BACKGROUND AND PURPOSE To quantify intra-fraction tumor motion using imageguidance and implanted fiducial markers to determine if a 5 mm planning-target-volume (PTV) margin is sufficient for early stage breast cancer patients receiving neoadjuvant stereotactic ablative radiotherapy (SABR). MATERIALS AND METHODS A HydroMark© (Mammotome) fiducial was implanted at the time of biopsy adjacent to the tumor. Sixty-one patients with 62 tumours were treated prone using a 5 mm PTV margin. Motion was quantified using two methods (separate patient groups): 1) difference in 3D fiducial position pre- and post-treatment cone-beam CTs (CBCTs) in 18 patients receiving 21 Gy/1fraction (fx); 2) acquiring 2D triggered-kVimages to quantify 3D intra-fraction motion using a 2D-to-3D estimation method for 44 tumours receiving 21 Gy/1fx (n = 22) or 30 Gy/3fx (n = 22). For 2), motion was quantified by calculating the magnitude of intra-fraction positional deviation from the pretreatment CBCT. PTV margins were derived using van Herkian analysis. RESULTS The average ± standard deviation magnitude of motion across patients was 1.3 ± 1.15 mm Left/Right (L/R), 1.0 ± 0.9 mm Inferiorly/Superiorly (I/S), and 1.8 ± 1.5 mm Anteriorly/Posteriorly (A/P). 85/105 (81%) treatment fractions had dominant anterior motion. 6/62patients (9.7%) had mean intra-fraction motion during any fraction > 5 mm in any direction, with 4 in the anterior direction. Estimated PTV margins for single and three-fx patients in the L/R, I/S, and A/P directions were 6.0x4.1x5.9 mm and 4.5x2.9x4.3 mm, respectively. CONCLUSION Our results suggest that a 5 mm PTV margin is sufficient for the I/S and A/P directions if a lateral kV image is acquired immediately before treatment. For the L/R direction, either further immobilization or a larger margin is required.
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Affiliation(s)
- Matthew Mouawad
- Medical Biophysics, Western University, London, Canada; London Health Sciences Centre, London, Canada.
| | - Owen Lailey
- London Health Sciences Centre, London, Canada
| | - Per Poulsen
- Danish Center for Particle Therapy and Department of Oncology, Aarhus University Hospital, Denmark.
| | | | - Muriel Brackstone
- Medical Biophysics, Western University, London, Canada; London Health Sciences Centre, London, Canada; Lawson Health Research Institute, London, Canada; St. Joseph's Health Care, London, Canada.
| | - Michael Lock
- London Health Sciences Centre, London, Canada; Department of Oncology, Western University, London, Canada.
| | - Brian Yaremko
- London Health Sciences Centre, London, Canada; Department of Oncology, Western University, London, Canada.
| | - Olga Shmuilovich
- Lawson Health Research Institute, London, Canada; St. Joseph's Health Care, London, Canada; Department of Medical Imaging, Western University, London, Canada.
| | - Anat Kornecki
- Lawson Health Research Institute, London, Canada; St. Joseph's Health Care, London, Canada; Department of Medical Imaging, Western University, London, Canada.
| | - Ilanit Ben Nachum
- Lawson Health Research Institute, London, Canada; St. Joseph's Health Care, London, Canada; Department of Medical Imaging, Western University, London, Canada.
| | - Giulio Muscedere
- Lawson Health Research Institute, London, Canada; St. Joseph's Health Care, London, Canada; Department of Medical Imaging, Western University, London, Canada.
| | - Kalan Lynn
- London Health Sciences Centre, London, Canada; Lawson Health Research Institute, London, Canada; St. Joseph's Health Care, London, Canada.
| | | | - Frank S Prato
- Medical Biophysics, Western University, London, Canada; Lawson Health Research Institute, London, Canada; St. Joseph's Health Care, London, Canada; Department of Medical Imaging, Western University, London, Canada.
| | - R Terry Thompson
- Medical Biophysics, Western University, London, Canada; Lawson Health Research Institute, London, Canada.
| | - Stewart Gaede
- Medical Biophysics, Western University, London, Canada; London Health Sciences Centre, London, Canada; Lawson Health Research Institute, London, Canada; Department of Oncology, Western University, London, Canada.
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20
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Poirier SE, Kwan BYM, Jurkiewicz MT, Samargandy L, Iacobelli M, Steven DA, Lam Shin Cheung V, Moran G, Prato FS, Thompson RT, Burneo JG, Anazodo UC, Thiessen JD. An evaluation of the diagnostic equivalence of 18F-FDG-PET between hybrid PET/MRI and PET/CT in drug-resistant epilepsy: A pilot study. Epilepsy Res 2021; 172:106583. [PMID: 33636504 DOI: 10.1016/j.eplepsyres.2021.106583] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 01/27/2021] [Accepted: 02/09/2021] [Indexed: 01/19/2023]
Abstract
OBJECTIVE Hybrid PET/MRI may improve detection of seizure-onset zone (SOZ) in drug-resistant epilepsy (DRE), however, concerns over PET bias from MRI-based attenuation correction (MRAC) have limited clinical adoption of PET/MRI. This study evaluated the diagnostic equivalency and potential clinical value of PET/MRI against PET/CT in DRE. MATERIALS AND METHODS MRI, FDG-PET and CT images (n = 18) were acquired using a hybrid PET/MRI and a CT scanner. To assess diagnostic equivalency, PET was reconstructed using MRAC (RESOLUTE) and CT-based attenuation correction (CTAC) to generate PET/MRI and PET/CT images, respectively. PET/MRI and PET/CT images were compared qualitatively through visual assessment and quantitatively through regional standardized uptake value (SUV) and z-score assessment. Diagnostic accuracy and sensitivity of PET/MRI and PET/CT for SOZ detection were calculated through comparison to reference standards (clinical hypothesis and histopathology, respectively). RESULTS Inter-reader agreement in visual assessment of PET/MRI and PET/CT images was 78 % and 81 %, respectively. PET/MRI and PET/CT were strongly correlated in mean SUV (r = 0.99, p < 0.001) and z-scores (r = 0.92, p < 0.001) across all brain regions. MRAC SUV bias was <5% in most brain regions except the inferior temporal gyrus, temporal pole, and cerebellum. Diagnostic accuracy and sensitivity were similar between PET/MRI and PET/CT (87 % vs. 85 % and 83 % vs. 83 %, respectively). CONCLUSION We demonstrate here that PET/MRI with optimal MRAC can yield similar diagnostic performance as PET/CT. Nevertheless, further exploration of the potential added value of PET/MRI is necessary before clinical adoption of PET/MRI for epilepsy imaging.
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Affiliation(s)
- Stefan E Poirier
- Lawson Imaging, Lawson Health Research Institute, London, ON, Canada; Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.
| | - Benjamin Y M Kwan
- Department of Diagnostic Radiology, Queen's University, Kingston, ON, Canada
| | - Michael T Jurkiewicz
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Lina Samargandy
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Maryssa Iacobelli
- Lawson Imaging, Lawson Health Research Institute, London, ON, Canada
| | - David A Steven
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada; Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Victor Lam Shin Cheung
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | | | - Frank S Prato
- Lawson Imaging, Lawson Health Research Institute, London, ON, Canada; Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada; Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - R Terry Thompson
- Lawson Imaging, Lawson Health Research Institute, London, ON, Canada; Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada; Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Jorge G Burneo
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada; Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Udunna C Anazodo
- Lawson Imaging, Lawson Health Research Institute, London, ON, Canada; Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada; Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada; Research Centre for Studies in Aging, McGill University, Montréal, QC, Canada.
| | - Jonathan D Thiessen
- Lawson Imaging, Lawson Health Research Institute, London, ON, Canada; Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada; Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
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21
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Wisenberg G, Thiessen JD, Pavlovsky W, Butler J, Wilk B, Prato FS. Same day comparison of PET/CT and PET/MR in patients with cardiac sarcoidosis. J Nucl Cardiol 2020; 27:2118-2129. [PMID: 30603887 PMCID: PMC7749056 DOI: 10.1007/s12350-018-01578-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Revised: 12/11/2018] [Indexed: 11/25/2022]
Abstract
BACKGROUND Inflammatory cardiac disorders, in particular, sarcoidosis, play an important role in left ventricular dysfunction, conduction abnormalities, and arrhythmias. In this study, we compared the imaging characteristics and diagnostic information obtained when patients were imaged sequentially with PET/CT and then with hybrid PET/MRI on the same day following a single 18F-FDG injection. METHODS Ten patients with known or suspected sarcoidosis underwent imaging in sequence of (a) 99mTc-MIBI, (b) 18F-FDG with PET/CT, and (c) 18F-FDG with 3T PET/MRI. Images were compared quantitatively by determination of SUVmax and SUV on a voxel by voxel basis, and qualitatively by two experienced observers. RESULTS When both platforms were compared quantitatively, similar data for the evaluation of enhanced 18F-FDG uptake were obtained. Qualitatively, there were (1) several instances of normal perfusion with delayed enhancement and/or focal 18F-FDG uptake, (2) comparable enhanced 18F-FDG uptake on PET/CT vs. PET/MRI, and (3) diversity in disease patterns with delayed enhancement only, increased 18F-FDG uptake only, or both. CONCLUSION In this limited patient study, PET/CT and PET/MR provided similar diagnostic data for 18F-FDG uptake, and the concurrent acquisition of MR images provided further insight into the disease process.
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Affiliation(s)
- G Wisenberg
- Departments of Medicine, Medical Imaging, and Medical Biophysics, Western University, London, ON, Canada.
- MyHealth Centre, 21589 Richmond Street, Arva, ON, N0M 1C0, Canada.
| | - J D Thiessen
- Departments of Medical Biophysics, Medical Imaging and Physics and Astronomy, Western University, London, ON, Canada
- Lawson Health Research Institute, London, ON, Canada
| | - W Pavlovsky
- Department of Medical Imaging, Western University, London, ON, Canada
| | - J Butler
- Division of Nuclear Medicine, St. Joseph's Hospital, London, ON, Canada
- Lawson Health Research Institute, London, ON, Canada
| | - B Wilk
- Lawson Health Research Institute, London, ON, Canada
| | - F S Prato
- Departments of Medical Biophysics, Medical Imaging and Physics and Astronomy, Western University, London, ON, Canada
- Lawson Health Research Institute, London, ON, Canada
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22
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Wilk B, Wisenberg G, Dharmakumar R, Thiessen JD, Goldhawk DE, Prato FS. Hybrid PET/MR imaging in myocardial inflammation post-myocardial infarction. J Nucl Cardiol 2020; 27:2083-2099. [PMID: 31797321 PMCID: PMC7391987 DOI: 10.1007/s12350-019-01973-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 11/13/2019] [Accepted: 11/14/2019] [Indexed: 01/24/2023]
Abstract
Hybrid PET/MR imaging is an emerging imaging modality combining positron emission tomography (PET) and magnetic resonance imaging (MRI) in the same system. Since the introduction of clinical PET/MRI in 2011, it has had some impact (e.g., imaging the components of inflammation in myocardial infarction), but its role could be much greater. Many opportunities remain unexplored and will be highlighted in this review. The inflammatory process post-myocardial infarction has many facets at a cellular level which may affect the outcome of the patient, specifically the effects on adverse left ventricular remodeling, and ultimately prognosis. The goal of inflammation imaging is to track the process non-invasively and quantitatively to determine the best therapeutic options for intervention and to monitor those therapies. While PET and MRI, acquired separately, can image aspects of inflammation, hybrid PET/MRI has the potential to advance imaging of myocardial inflammation. This review contains a description of hybrid PET/MRI, its application to inflammation imaging in myocardial infarction and the challenges, constraints, and opportunities in designing data collection protocols. Finally, this review explores opportunities in PET/MRI: improved registration, partial volume correction, machine learning, new approaches in the development of PET and MRI pulse sequences, and the use of novel injection strategies.
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Affiliation(s)
- B Wilk
- Department of Medical Imaging, Western University, London, Canada.
- Lawson Health Research Institute, London, Canada.
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Canada.
| | - G Wisenberg
- Department of Medical Imaging, Western University, London, Canada
- MyHealth Centre, Arva, Canada
| | - R Dharmakumar
- Biomedical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
- David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - J D Thiessen
- Department of Medical Imaging, Western University, London, Canada
- Lawson Health Research Institute, London, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Canada
| | - D E Goldhawk
- Department of Medical Imaging, Western University, London, Canada
- Lawson Health Research Institute, London, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Canada
| | - F S Prato
- Department of Medical Imaging, Western University, London, Canada
- Lawson Health Research Institute, London, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Canada
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23
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Yang HJ, Oksuz I, Dey D, Sykes J, Klein M, Butler J, Kovacs MS, Sobczyk O, Cokic I, Slomka PJ, Bi X, Li D, Tighiouart M, Tsaftaris SA, Prato FS, Fisher JA, Dharmakumar R. Accurate needle-free assessment of myocardial oxygenation for ischemic heart disease in canines using magnetic resonance imaging. Sci Transl Med 2020; 11:11/494/eaat4407. [PMID: 31142677 DOI: 10.1126/scitranslmed.aat4407] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/08/2019] [Indexed: 12/24/2022]
Abstract
Myocardial oxygenation-the ability of blood vessels to supply the heart muscle (myocardium) with oxygen-is a critical determinant of cardiac function. Impairment of myocardial oxygenation is a defining feature of ischemic heart disease (IHD), which is caused by pathological conditions that affect the blood vessels supplying oxygen to the heart muscle. Detecting altered myocardial oxygenation can help guide interventions and prevent acute life-threatening events such as heart attacks (myocardial infarction); however, current diagnosis of IHD relies on surrogate metrics and exogenous contrast agents for which many patients are contraindicated. An oxygenation-sensitive cardiac magnetic resonance imaging (CMR) approach used previously to demonstrate that CMR signals can be sensitized to changes in myocardial oxygenation showed limited ability to detect small changes in signals in the heart because of physiologic and imaging noise during data acquisition. Here, we demonstrate a CMR-based approach termed cfMRI [cardiac functional magnetic resonance imaging (MRI)] that detects myocardial oxygenation. cfMRI uses carbon dioxide for repeat interrogation of the functional capacity of the heart's blood vessels via a fast MRI approach suitable for clinical adoption without limitations of key confounders (cardiac/respiratory motion and heart rate changes). This method integrates multiple whole-heart images within a computational framework to reduce noise, producing confidence maps of alterations in myocardial oxygenation. cfMRI permits noninvasive monitoring of myocardial oxygenation without requiring ionizing radiation, contrast agents, or needles. This has the potential to broaden our ability to noninvasively identify IHD and a diverse spectrum of heart diseases related to myocardial ischemia.
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Affiliation(s)
- Hsin-Jung Yang
- Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.,University of California, Los Angeles CA 90095, USA
| | | | - Damini Dey
- Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.,University of California, Los Angeles CA 90095, USA
| | - Jane Sykes
- Lawson Health Research Institute, University of Western Ontario, London, ON N6C 2R5, Canada
| | - Michael Klein
- University of Toronto and University Health Network, Toronto, ON M5G 2C4, Canada
| | - John Butler
- Lawson Health Research Institute, University of Western Ontario, London, ON N6C 2R5, Canada
| | - Michael S Kovacs
- Lawson Health Research Institute, University of Western Ontario, London, ON N6C 2R5, Canada
| | - Olivia Sobczyk
- University of Toronto and University Health Network, Toronto, ON M5G 2C4, Canada
| | - Ivan Cokic
- Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Piotr J Slomka
- Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.,University of California, Los Angeles CA 90095, USA
| | - Xiaoming Bi
- MR R&D Collaborations, Siemens Healthineers, Los Angeles, CA 90048, USA
| | - Debiao Li
- Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.,University of California, Los Angeles CA 90095, USA
| | | | | | - Frank S Prato
- Lawson Health Research Institute, University of Western Ontario, London, ON N6C 2R5, Canada
| | - Joseph A Fisher
- University of Toronto and University Health Network, Toronto, ON M5G 2C4, Canada
| | - Rohan Dharmakumar
- Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA. .,University of California, Los Angeles CA 90095, USA
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Poirier SE, Kwan BYM, Jurkiewicz MT, Samargandy L, Steven DA, Suller-Marti A, Lam Shin Cheung V, Khan AR, Romsa J, Prato FS, Burneo JG, Thiessen JD, Anazodo UC. 18F-FDG PET-guided diffusion tractography reveals white matter abnormalities around the epileptic focus in medically refractory epilepsy: implications for epilepsy surgical evaluation. Eur J Hybrid Imaging 2020; 4:10. [PMID: 34191151 PMCID: PMC8218143 DOI: 10.1186/s41824-020-00079-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 06/12/2020] [Indexed: 02/28/2023] Open
Abstract
BACKGROUND Hybrid PET/MRI can non-invasively improve localization and delineation of the epileptic focus (EF) prior to surgical resection in medically refractory epilepsy (MRE), especially when MRI is negative or equivocal. In this study, we developed a PET-guided diffusion tractography (PET/DTI) approach combining 18F-fluorodeoxyglucose PET (FDG-PET) and diffusion MRI to investigate white matter (WM) integrity in MRI-negative MRE patients and its potential impact on epilepsy surgical planning. METHODS FDG-PET and diffusion MRI of 14 MRI-negative or equivocal MRE patients were used to retrospectively pilot the PET/DTI approach. We used asymmetry index (AI) mapping of FDG-PET to detect the EF as brain areas showing the largest decrease in FDG uptake between hemispheres. Seed-based WM fiber tracking was performed on DTI images with a seed location in WM 3 mm from the EF. Fiber tractography was repeated in the contralateral brain region (opposite to EF), which served as a control for this study. WM fibers were quantified by calculating the fiber count, mean fractional anisotropy (FA), mean fiber length, and mean cross-section of each fiber bundle. WM integrity was assessed through fiber visualization and by normalizing ipsilateral fiber measurements to contralateral fiber measurements. The added value of PET/DTI in clinical decision-making was evaluated by a senior neurologist. RESULTS In over 60% of the patient cohort, AI mapping findings were concordant with clinical reports on seizure-onset localization and lateralization. Mean FA, fiber count, and mean fiber length were decreased in 14/14 (100%), 13/14 (93%), and 12/14 (86%) patients, respectively. PET/DTI improved diagnostic confidence in 10/14 (71%) patients and indicated that surgical candidacy be reassessed in 3/6 (50%) patients who had not undergone surgery. CONCLUSIONS We demonstrate here the utility of AI mapping in detecting the EF based on brain regions showing decreased FDG-PET activity and, when coupled with DTI, could be a powerful tool for detecting EF and assessing WM integrity in MRI-negative epilepsy. PET/DTI could be used to further enhance clinical decision-making in epilepsy surgery.
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Affiliation(s)
- Stefan E Poirier
- Lawson Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, Ontario, N6A 4 V2, Canada. .,Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.
| | - Benjamin Y M Kwan
- Department of Diagnostic Radiology, Queen's University, Kingston, Ontario, Canada
| | - Michael T Jurkiewicz
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Lina Samargandy
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - David A Steven
- Epilepsy Program, Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.,Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Ana Suller-Marti
- Epilepsy Program, Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | | | - Ali R Khan
- Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.,Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.,Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada
| | - Jonathan Romsa
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Frank S Prato
- Lawson Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, Ontario, N6A 4 V2, Canada.,Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.,Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Jorge G Burneo
- Epilepsy Program, Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.,Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Jonathan D Thiessen
- Lawson Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, Ontario, N6A 4 V2, Canada.,Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.,Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Udunna C Anazodo
- Lawson Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, Ontario, N6A 4 V2, Canada. .,Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.
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25
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Farag A, Thompson RT, Thiessen JD, Biernaski H, Prato FS, Théberge J. Evaluation of 511 keV photon attenuation by a novel 32-channel phased array prospectively designed for cardiovascular hybrid PET/MRI imaging. Eur J Hybrid Imaging 2020; 4:7. [PMID: 32626841 PMCID: PMC7324084 DOI: 10.1186/s41824-020-00076-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 04/29/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Simultaneous cardiovascular imaging with positron emission tomography (PET) and magnetic resonance imaging (MRI) requires tools such as radio frequency (RF) phased arrays to achieve high temporal and spatial resolution in the MRI, as well as accurate quantification of PET. Today, high-density phased arrays (> 16 channels) used for cardiovascular PET/MRI are not designed to achieve low PET attenuation, and correcting the PET attenuation they cause requires off-line reconstruction, extra time and resources. PURPOSE Motivated by previous work assessing the MRI performance of a novel prospectively designed 32-channel phased array, this study assessed the PET image quality with this array in place. Guided by NEMA standards, PET performance was measured using global PET counts, regional background variation (BV), contrast recovery (CR) and contrast-to-noise ratio (CNR) for both the novel array and standard arrays (mMR 12-channel and MRI 32-channel). Nonattenuation-corrected (NAC) data from all arrays (and each part of the array) were processed and compared to no-array, and relative percentage difference (RPD) of the global means was estimated and reported for each part of the arrays. Attenuation correction (AC) of PET images (water in the phantom) using two approaches, MR-based AC map (MRAC) and dual-energy CT-based map (DCTAC), was performed, and RPD compared for each part of the arrays. Percent mean attenuation within regions of interests of the phantom images from each array were compared using a two-way analysis of variance (ANOVA). RESULTS The NAC data of the anterior part of the novel array recorded the least PET attenuation (≤ 2%); while the full novel array (anterior and posterior together) AC data, produced by MRAC and DCTAC approaches, recorded attenuation of 1.5 ± 2.9% and 0.0 ± 2.5%, respectively. The novel array PET count loss was significantly lower (p = 0.001) than those caused by the standard arrays. CONCLUSIONS Results of this novel 32-channel cardiac array PET performance evaluation, together with its previously reported MRI performance assessment, suggest the novel array to be a strong alternative to the standard arrays currently used for cardiovascular hybrid PET/MRI imaging. It enables accurate PET quantification and high-temporal and spatial resolution for MR imaging.
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Affiliation(s)
- Adam Farag
- Imaging Division, Lawson Health Research Institute, London, Ontario Canada
- Department of Medical Biophysics, Western University, London, Ontario Canada
| | - R. Terry Thompson
- Imaging Division, Lawson Health Research Institute, London, Ontario Canada
- Department of Medical Biophysics, Western University, London, Ontario Canada
| | - Jonathan D. Thiessen
- Imaging Division, Lawson Health Research Institute, London, Ontario Canada
- Department of Medical Biophysics, Western University, London, Ontario Canada
- Department of Medical Imaging, Western University, London, Ontario Canada
| | - Heather Biernaski
- Imaging Division, Lawson Health Research Institute, London, Ontario Canada
| | - Frank S. Prato
- Imaging Division, Lawson Health Research Institute, London, Ontario Canada
- Department of Medical Biophysics, Western University, London, Ontario Canada
- Department of Medical Imaging, Western University, London, Ontario Canada
- Diagnostic Imaging, St. Joseph’s Health Care, London, Ontario Canada
| | - Jean Théberge
- Imaging Division, Lawson Health Research Institute, London, Ontario Canada
- Department of Medical Biophysics, Western University, London, Ontario Canada
- Department of Medical Imaging, Western University, London, Ontario Canada
- Diagnostic Imaging, St. Joseph’s Health Care, London, Ontario Canada
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26
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Yang HJ, Dey D, Sykes J, Butler J, Biernaski H, Kovacs M, Bi X, Sharif B, Cokic I, Tang R, Slomka P, Prato FS, Dharmakumar R. Heart Rate-Independent 3D Myocardial Blood Oxygen Level-Dependent MRI at 3.0 T with Simultaneous 13N-Ammonia PET Validation. Radiology 2020; 295:82-93. [PMID: 32096705 PMCID: PMC7106942 DOI: 10.1148/radiol.2020191456] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 12/20/2019] [Accepted: 01/03/2020] [Indexed: 11/11/2022]
Abstract
Background Despite advances, blood oxygen level-dependent (BOLD) cardiac MRI for myocardial perfusion is limited by inadequate spatial coverage, imaging speed, multiple breath holds, and imaging artifacts, particularly at 3.0 T. Purpose To develop and validate a robust, contrast agent-unenhanced, free-breathing three-dimensional (3D) cardiac MRI approach for reliably examining changes in myocardial perfusion between rest and adenosine stress. Materials and Methods A heart rate-independent, free-breathing 3D T2 mapping technique at 3.0 T that can be completed within the period of adenosine stress (≤4 minutes) was developed by using computer simulations, ex vivo heart preparations, and dogs. Studies in dogs were performed with and without coronary stenosis and validated with simultaneously acquired nitrogen 13 (13N) ammonia PET perfusion in a clinical PET/MRI system. The MRI approach was also prospectively evaluated in healthy human volunteers (from January 2017 to September 2017). Myocardial BOLD responses (MBRs) between normal and ischemic myocardium were compared with mixed model analysis. Results Dogs (n = 10; weight range, 20-25 kg; mongrel dogs) and healthy human volunteers (n = 10; age range, 22-53 years; seven men) were evaluated. In healthy dogs, T2 MRI at adenosine stress was greater than at rest (mean rest vs stress, 38.7 msec ± 2.5 [standard deviation] vs 45.4 msec ± 3.3, respectively; MBR, 1.19 ± 0.08; both, P < .001). At the same conditions, mean rest versus stress PET perfusion was 1.1 mL/mg/min ± 0.11 versus 2.3 mL/mg/min ± 0.82, respectively (P < .001); myocardial perfusion reserve (MPR) was 2.4 ± 0.82 (P < .001). The BOLD response and PET MPR were positively correlated (R = 0.67; P < .001). In dogs with coronary stenosis, perfusion anomalies were detected on the basis of MBR (normal vs ischemic, 1.09 ± 0.05 vs 1.00 ± 0.04, respectively; P < .001) and MPR (normal vs ischemic, 2.7 ± 0.08 vs 1.7 ± 1.1, respectively; P < .001). Human volunteers showed increased myocardial T2 at stress (rest vs stress, 44.5 msec ± 2.6 vs 49.0 msec ± 5.5, respectively; P = .004; MBR, 1.1 msec ± 8.08). Conclusion This three-dimensional cardiac blood oxygen level-dependent (BOLD) MRI approach overcame key limitations associated with conventional cardiac BOLD MRI by enabling whole-heart coverage within the standard duration of adenosine infusion, and increased the magnitude and reliability of BOLD contrast, which may be performed without requiring breath holds. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Almeida in this issue.
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Affiliation(s)
- Hsin-Jung Yang
- From the Department of Biomedical Sciences, Cedars-Sinai Medical
Center, Biomedical Imaging Research Institute, PACT Bldg–Suite 400, 8700
Beverly Blvd, Los Angeles, CA 90048 (H.J.Y., D.D., B.S., I.C., R.T., P.S.,
R.D.); Department of Bioengineering (H.J.Y., R.D.) and David Geffen School of
Medicine (D.D., P.S.), University of California, Los Angeles Calif; Lawson
Health Research Institute, London, Canada (J.S., J.B., H.B., M.K., F.S.P.); and
MR R&D, Siemens Healthcare, Los Angeles, Calif (X.B.)
| | - Damini Dey
- From the Department of Biomedical Sciences, Cedars-Sinai Medical
Center, Biomedical Imaging Research Institute, PACT Bldg–Suite 400, 8700
Beverly Blvd, Los Angeles, CA 90048 (H.J.Y., D.D., B.S., I.C., R.T., P.S.,
R.D.); Department of Bioengineering (H.J.Y., R.D.) and David Geffen School of
Medicine (D.D., P.S.), University of California, Los Angeles Calif; Lawson
Health Research Institute, London, Canada (J.S., J.B., H.B., M.K., F.S.P.); and
MR R&D, Siemens Healthcare, Los Angeles, Calif (X.B.)
| | - Jane Sykes
- From the Department of Biomedical Sciences, Cedars-Sinai Medical
Center, Biomedical Imaging Research Institute, PACT Bldg–Suite 400, 8700
Beverly Blvd, Los Angeles, CA 90048 (H.J.Y., D.D., B.S., I.C., R.T., P.S.,
R.D.); Department of Bioengineering (H.J.Y., R.D.) and David Geffen School of
Medicine (D.D., P.S.), University of California, Los Angeles Calif; Lawson
Health Research Institute, London, Canada (J.S., J.B., H.B., M.K., F.S.P.); and
MR R&D, Siemens Healthcare, Los Angeles, Calif (X.B.)
| | - John Butler
- From the Department of Biomedical Sciences, Cedars-Sinai Medical
Center, Biomedical Imaging Research Institute, PACT Bldg–Suite 400, 8700
Beverly Blvd, Los Angeles, CA 90048 (H.J.Y., D.D., B.S., I.C., R.T., P.S.,
R.D.); Department of Bioengineering (H.J.Y., R.D.) and David Geffen School of
Medicine (D.D., P.S.), University of California, Los Angeles Calif; Lawson
Health Research Institute, London, Canada (J.S., J.B., H.B., M.K., F.S.P.); and
MR R&D, Siemens Healthcare, Los Angeles, Calif (X.B.)
| | - Heather Biernaski
- From the Department of Biomedical Sciences, Cedars-Sinai Medical
Center, Biomedical Imaging Research Institute, PACT Bldg–Suite 400, 8700
Beverly Blvd, Los Angeles, CA 90048 (H.J.Y., D.D., B.S., I.C., R.T., P.S.,
R.D.); Department of Bioengineering (H.J.Y., R.D.) and David Geffen School of
Medicine (D.D., P.S.), University of California, Los Angeles Calif; Lawson
Health Research Institute, London, Canada (J.S., J.B., H.B., M.K., F.S.P.); and
MR R&D, Siemens Healthcare, Los Angeles, Calif (X.B.)
| | - Michael Kovacs
- From the Department of Biomedical Sciences, Cedars-Sinai Medical
Center, Biomedical Imaging Research Institute, PACT Bldg–Suite 400, 8700
Beverly Blvd, Los Angeles, CA 90048 (H.J.Y., D.D., B.S., I.C., R.T., P.S.,
R.D.); Department of Bioengineering (H.J.Y., R.D.) and David Geffen School of
Medicine (D.D., P.S.), University of California, Los Angeles Calif; Lawson
Health Research Institute, London, Canada (J.S., J.B., H.B., M.K., F.S.P.); and
MR R&D, Siemens Healthcare, Los Angeles, Calif (X.B.)
| | - Xiaoming Bi
- From the Department of Biomedical Sciences, Cedars-Sinai Medical
Center, Biomedical Imaging Research Institute, PACT Bldg–Suite 400, 8700
Beverly Blvd, Los Angeles, CA 90048 (H.J.Y., D.D., B.S., I.C., R.T., P.S.,
R.D.); Department of Bioengineering (H.J.Y., R.D.) and David Geffen School of
Medicine (D.D., P.S.), University of California, Los Angeles Calif; Lawson
Health Research Institute, London, Canada (J.S., J.B., H.B., M.K., F.S.P.); and
MR R&D, Siemens Healthcare, Los Angeles, Calif (X.B.)
| | - Behzad Sharif
- From the Department of Biomedical Sciences, Cedars-Sinai Medical
Center, Biomedical Imaging Research Institute, PACT Bldg–Suite 400, 8700
Beverly Blvd, Los Angeles, CA 90048 (H.J.Y., D.D., B.S., I.C., R.T., P.S.,
R.D.); Department of Bioengineering (H.J.Y., R.D.) and David Geffen School of
Medicine (D.D., P.S.), University of California, Los Angeles Calif; Lawson
Health Research Institute, London, Canada (J.S., J.B., H.B., M.K., F.S.P.); and
MR R&D, Siemens Healthcare, Los Angeles, Calif (X.B.)
| | - Ivan Cokic
- From the Department of Biomedical Sciences, Cedars-Sinai Medical
Center, Biomedical Imaging Research Institute, PACT Bldg–Suite 400, 8700
Beverly Blvd, Los Angeles, CA 90048 (H.J.Y., D.D., B.S., I.C., R.T., P.S.,
R.D.); Department of Bioengineering (H.J.Y., R.D.) and David Geffen School of
Medicine (D.D., P.S.), University of California, Los Angeles Calif; Lawson
Health Research Institute, London, Canada (J.S., J.B., H.B., M.K., F.S.P.); and
MR R&D, Siemens Healthcare, Los Angeles, Calif (X.B.)
| | - Richard Tang
- From the Department of Biomedical Sciences, Cedars-Sinai Medical
Center, Biomedical Imaging Research Institute, PACT Bldg–Suite 400, 8700
Beverly Blvd, Los Angeles, CA 90048 (H.J.Y., D.D., B.S., I.C., R.T., P.S.,
R.D.); Department of Bioengineering (H.J.Y., R.D.) and David Geffen School of
Medicine (D.D., P.S.), University of California, Los Angeles Calif; Lawson
Health Research Institute, London, Canada (J.S., J.B., H.B., M.K., F.S.P.); and
MR R&D, Siemens Healthcare, Los Angeles, Calif (X.B.)
| | - Piotr Slomka
- From the Department of Biomedical Sciences, Cedars-Sinai Medical
Center, Biomedical Imaging Research Institute, PACT Bldg–Suite 400, 8700
Beverly Blvd, Los Angeles, CA 90048 (H.J.Y., D.D., B.S., I.C., R.T., P.S.,
R.D.); Department of Bioengineering (H.J.Y., R.D.) and David Geffen School of
Medicine (D.D., P.S.), University of California, Los Angeles Calif; Lawson
Health Research Institute, London, Canada (J.S., J.B., H.B., M.K., F.S.P.); and
MR R&D, Siemens Healthcare, Los Angeles, Calif (X.B.)
| | - Frank S. Prato
- From the Department of Biomedical Sciences, Cedars-Sinai Medical
Center, Biomedical Imaging Research Institute, PACT Bldg–Suite 400, 8700
Beverly Blvd, Los Angeles, CA 90048 (H.J.Y., D.D., B.S., I.C., R.T., P.S.,
R.D.); Department of Bioengineering (H.J.Y., R.D.) and David Geffen School of
Medicine (D.D., P.S.), University of California, Los Angeles Calif; Lawson
Health Research Institute, London, Canada (J.S., J.B., H.B., M.K., F.S.P.); and
MR R&D, Siemens Healthcare, Los Angeles, Calif (X.B.)
| | - Rohan Dharmakumar
- From the Department of Biomedical Sciences, Cedars-Sinai Medical
Center, Biomedical Imaging Research Institute, PACT Bldg–Suite 400, 8700
Beverly Blvd, Los Angeles, CA 90048 (H.J.Y., D.D., B.S., I.C., R.T., P.S.,
R.D.); Department of Bioengineering (H.J.Y., R.D.) and David Geffen School of
Medicine (D.D., P.S.), University of California, Los Angeles Calif; Lawson
Health Research Institute, London, Canada (J.S., J.B., H.B., M.K., F.S.P.); and
MR R&D, Siemens Healthcare, Los Angeles, Calif (X.B.)
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Mouawad M, Biernaski H, Brackstone M, Lock M, Yaremko B, Shmuilovich O, Kornecki A, Ben Nachum I, Muscedere G, Lynn K, Prato FS, Thompson RT, Gaede S, Gelman N. DCE-MRI assessment of response to neoadjuvant SABR in early stage breast cancer: Comparisons of single versus three fraction schemes and two different imaging time delays post-SABR. Clin Transl Radiat Oncol 2020; 21:25-31. [PMID: 32021911 PMCID: PMC6993055 DOI: 10.1016/j.ctro.2019.12.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 12/22/2019] [Indexed: 12/25/2022] Open
Abstract
PURPOSE To determine the effect of dose fractionation and time delay post-neoadjuvant stereotactic ablative radiotherapy (SABR) on dynamic contrast-enhanced (DCE)-MRI parameters in early stage breast cancer patients. MATERIALS AND METHODS DCE-MRI was acquired in 17 patients pre- and post-SABR. Five patients were imaged 6-7 days post-21 Gy/1fraction (group 1), six 16-19 days post-21 Gy/1fraction (group 2), and six 16-18 days post-30 Gy/3 fractions every other day (group 3). DCE-MRI scans were performed using half the clinical dose of contrast agent. Changes in the surrounding tissue were quantified using a signal-enhancement threshold metric that characterizes changes in signal-enhancement volume (SEV). Tumour response was quantified using Ktrans and ve (Tofts model) pre- and post-SABR. Significance was assessed using a Wilcoxin signed-rank test. RESULTS All group 1 and 4/6 group 2 patients' SEV increased post-SABR. All group 3 patients' SEV decreased. The mean Ktrans increased for group 1 by 76% (p = 0.043) while group 2 and 3 decreased 15% (p = 0.028) and 34% (p = 0.028), respectively. For ve, there was no significant change in Group 1 (p = 0.35). Groups 2 showed an increase of 24% (p = 0.043), and Group 3 trended toward an increase (23%, p = 0.08). CONCLUSION Kinetic parameters measured 2.5 weeks post-SABR in both single fraction and three fraction groups were indicative of response but only the single fraction protocol led to enhancement in the surrounding tissue. Our results also suggest that DCE-MRI one-week post-SABR may be too early for response assessment, at least for single fraction SABR, whereas 2.5 weeks appears sufficiently long to minimize confounding acute effects.
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Affiliation(s)
- Matthew Mouawad
- Medical Biophysics, Western University, London, Ontario, Canada
| | | | - Muriel Brackstone
- Medical Biophysics, Western University, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada
- London Health Sciences Centre, London, Ontario, Canada
- St. Joseph’s Health Care, London, Ontario, Canada
| | - Michael Lock
- London Health Sciences Centre, London, Ontario, Canada
- Department of Oncology, Western University, London, Ontario, Canada
| | - Brian Yaremko
- London Health Sciences Centre, London, Ontario, Canada
- Department of Oncology, Western University, London, Ontario, Canada
| | - Olga Shmuilovich
- Lawson Health Research Institute, London, Ontario, Canada
- St. Joseph’s Health Care, London, Ontario, Canada
- Department of Medical Imaging, Western University, London, Ontario, Canada
| | - Anat Kornecki
- Lawson Health Research Institute, London, Ontario, Canada
- St. Joseph’s Health Care, London, Ontario, Canada
- Department of Medical Imaging, Western University, London, Ontario, Canada
| | - Ilanit Ben Nachum
- Lawson Health Research Institute, London, Ontario, Canada
- St. Joseph’s Health Care, London, Ontario, Canada
- Department of Medical Imaging, Western University, London, Ontario, Canada
| | - Giulio Muscedere
- Lawson Health Research Institute, London, Ontario, Canada
- St. Joseph’s Health Care, London, Ontario, Canada
- Department of Medical Imaging, Western University, London, Ontario, Canada
| | - Kalan Lynn
- Lawson Health Research Institute, London, Ontario, Canada
- London Health Sciences Centre, London, Ontario, Canada
- St. Joseph’s Health Care, London, Ontario, Canada
| | - Frank S. Prato
- Medical Biophysics, Western University, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada
- St. Joseph’s Health Care, London, Ontario, Canada
- Department of Medical Imaging, Western University, London, Ontario, Canada
| | - R. Terry Thompson
- Medical Biophysics, Western University, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada
| | - Stewart Gaede
- Medical Biophysics, Western University, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada
- London Health Sciences Centre, London, Ontario, Canada
- Department of Oncology, Western University, London, Ontario, Canada
| | - Neil Gelman
- Medical Biophysics, Western University, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada
- Department of Medical Imaging, Western University, London, Ontario, Canada
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28
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Alizadeh K, Sun Q, McGuire T, Thompson T, Prato FS, Koropatnick J, Gelman N, Goldhawk DE. Hepcidin-mediated Iron Regulation in P19 Cells is Detectable by Magnetic Resonance Imaging. Sci Rep 2020; 10:3163. [PMID: 32081948 PMCID: PMC7035373 DOI: 10.1038/s41598-020-59991-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Accepted: 02/04/2020] [Indexed: 01/25/2023] Open
Abstract
Magnetic resonance imaging can be used to track cellular activities in the body using iron-based contrast agents. However, multiple intrinsic cellular iron handling mechanisms may also influence the detection of magnetic resonance (MR) contrast: a need to differentiate among those mechanisms exists. In hepcidin-mediated inflammation, for example, downregulation of iron export in monocytes and macrophages involves post-translational degradation of ferroportin. We examined the influence of hepcidin endocrine activity on iron regulation and MR transverse relaxation rates in multi-potent P19 cells, which display high iron import and export activities, similar to alternatively-activated macrophages. Iron import and export were examined in cultured P19 cells in the presence and absence of iron-supplemented medium, respectively. Western blots indicated the levels of transferrin receptor, ferroportin and ubiquitin in the presence and absence of extracellular hepcidin. Total cellular iron was measured by inductively-coupled plasma mass spectrometry and correlated to transverse relaxation rates at 3 Tesla using a gelatin phantom. Under varying conditions of iron supplementation, the level of ferroportin in P19 cells responds to hepcidin regulation, consistent with degradation through a ubiquitin-mediated pathway. This response of P19 cells to hepcidin is similar to that of classically-activated macrophages. The correlation between total cellular iron content and MR transverse relaxation rates was different in hepcidin-treated and untreated P19 cells: slope, Pearson correlation coefficient and relaxation rate were all affected. These findings may provide a tool to non-invasively distinguish changes in endogenous iron contrast arising from hepcidin-ferroportin interactions, with potential utility in monitoring of different macrophage phenotypes involved in pro- and anti-inflammatory signaling. In addition, this work demonstrates that transverse relaxivity is not only influenced by the amount of cellular iron but also by its metabolism.
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Affiliation(s)
- Kobra Alizadeh
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
- Medical Biophysics, Western University, London, Ontario, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Ontario, Canada
| | - Qin Sun
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
- Medical Biophysics, Western University, London, Ontario, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Ontario, Canada
| | - Tabitha McGuire
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
| | - Terry Thompson
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
- Medical Biophysics, Western University, London, Ontario, Canada
- Medical Imaging, Western University, London, Ontario, Canada
- Physics and Astronomy, Western University, London, Ontario, Canada
| | - Frank S Prato
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
- Medical Biophysics, Western University, London, Ontario, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Ontario, Canada
- Medical Imaging, Western University, London, Ontario, Canada
- Physics and Astronomy, Western University, London, Ontario, Canada
| | - Jim Koropatnick
- London Regional Cancer Program, London, Ontario, Canada
- Oncology, Western University, London, Ontario, Canada
| | - Neil Gelman
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
- Medical Biophysics, Western University, London, Ontario, Canada
- Medical Imaging, Western University, London, Ontario, Canada
| | - Donna E Goldhawk
- Imaging, Lawson Health Research Institute, London, Ontario, Canada.
- Medical Biophysics, Western University, London, Ontario, Canada.
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Ontario, Canada.
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Farag A, Thompson RT, Thiessen JD, Butler J, Prato FS, Théberge J. Assessment of a novel 32-channel phased array for cardiovascular hybrid PET/MRI imaging: MRI performance. Eur J Hybrid Imaging 2019; 3:13. [PMID: 33283144 PMCID: PMC7717874 DOI: 10.1186/s41824-019-0061-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 07/01/2019] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Cardiovascular imaging using hybrid positron emission tomography (PET) and magnetic resonance imaging (MRI) requires a radio frequency phased array resonator capable of high acceleration factors in order to achieve the shortest breath-holds while maintaining optimal MRI signal-to-noise ratio (SNR) and minimum PET photon attenuation. To our knowledge, the only two arrays used today for hybrid PET/MRI cardiovascular imaging are either incapable of achieving high acceleration or affect the PET photon count greatly. PURPOSE This study is focused on the evaluation of the MRI performance of a novel third-party prototype 32-channel phased array designed for simultaneous PET/MRI cardiovascular imaging. The study compares the quality parameters of MRI parallel imaging, such as g-factor, noise correlation coefficients, and SNR, to the conventional arrays (mMR 12-channel and MRI-only 32-channel) currently used with hybrid PET/MRI systems. The quality parameters of parallel imaging were estimated for multiple acceleration factors on a phantom and three healthy volunteers. Using a Germanium-68 (Ge-68) phantom, preliminary measurements of PET photon attenuation caused by the novel array were briefly compared to the photon counts produced from no-array measurements. RESULTS The global mean of the g-factor and SNRg produced by the novel 32-channel PET/MRI array were better than those produced by the MRI-only 32-channel array by 5% or more. The novel array has resulted in MRI SNR improvements of > 30% at all acceleration factors, in comparison to the mMR12-channel array. Preliminary evaluation of PET transparency showed less than 5% photon attenuation caused by both anterior and posterior parts of the novel array. CONCLUSIONS The MRI performance of the novel PET/MRI 32-channel array qualifies it to be a viable alternative to the conventional arrays for cardiovascular hybrid PET/MRI. A detailed evaluation of the novel array's PET performance remains to be conducted, but cursory assessment promises significantly reduced attenuation.
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Affiliation(s)
- Adam Farag
- Lawson Health Research Institute, Imaging Division, 268 Grosvenor St., Rm E5-118, PO Box 5777, STN B, London, ON N6A 4V2 Canada
- Department of Medical Biophysics, Western University, London, ON Canada
| | - R. Terry Thompson
- Lawson Health Research Institute, Imaging Division, 268 Grosvenor St., Rm E5-118, PO Box 5777, STN B, London, ON N6A 4V2 Canada
- Department of Medical Biophysics, Western University, London, ON Canada
| | - Jonathan D. Thiessen
- Lawson Health Research Institute, Imaging Division, 268 Grosvenor St., Rm E5-118, PO Box 5777, STN B, London, ON N6A 4V2 Canada
- Department of Medical Biophysics, Western University, London, ON Canada
- Department of Medical Imaging, Western University, London, ON Canada
| | - John Butler
- Lawson Health Research Institute, Imaging Division, 268 Grosvenor St., Rm E5-118, PO Box 5777, STN B, London, ON N6A 4V2 Canada
| | - Frank S. Prato
- Lawson Health Research Institute, Imaging Division, 268 Grosvenor St., Rm E5-118, PO Box 5777, STN B, London, ON N6A 4V2 Canada
- Department of Medical Biophysics, Western University, London, ON Canada
- Department of Medical Imaging, Western University, London, ON Canada
- St. Joseph’s Health Care, Diagnostic Imaging, London, ON Canada
| | - Jean Théberge
- Lawson Health Research Institute, Imaging Division, 268 Grosvenor St., Rm E5-118, PO Box 5777, STN B, London, ON N6A 4V2 Canada
- Department of Medical Biophysics, Western University, London, ON Canada
- Department of Medical Imaging, Western University, London, ON Canada
- St. Joseph’s Health Care, Diagnostic Imaging, London, ON Canada
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30
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Garcia J, Sheitt H, Bristow MS, Lydell C, Howarth AG, Heydari B, Prato FS, Drangova M, Thornhill RE, Nery P, Wilton SB, Skanes A, White JA. Left atrial vortex size and velocity distributions by 4D flow MRI in patients with paroxysmal atrial fibrillation: Associations with age and CHA
2
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‐VASc risk score. J Magn Reson Imaging 2019; 51:871-884. [DOI: 10.1002/jmri.26876] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 07/03/2019] [Accepted: 07/05/2019] [Indexed: 12/21/2022] Open
Affiliation(s)
- Julio Garcia
- Department of Cardiac SciencesUniversity of Calgary Calgary AB Canada
- Department of RadiologyUniversity of Calgary Calgary AB Canada
- Stephenson Cardiac Imaging CentreUniversity of Calgary AB Canada
- Libin Cardiovascular Institute of Alberta Calgary AB Canada
- Alberta Children's Hospital Research Institute
| | - Hana Sheitt
- Department of Cardiac SciencesUniversity of Calgary Calgary AB Canada
| | - Michael S. Bristow
- Department of Cardiac SciencesUniversity of Calgary Calgary AB Canada
- Department of MedicineUniversity of Calgary Calgary AB Canada
| | - Carmen Lydell
- Department of Cardiac SciencesUniversity of Calgary Calgary AB Canada
- Diagnostic ImagingUniversity of Calgary Calgary AB Canada
| | - Andrew G. Howarth
- Department of Cardiac SciencesUniversity of Calgary Calgary AB Canada
- Stephenson Cardiac Imaging CentreUniversity of Calgary AB Canada
| | - Bobak Heydari
- Department of Cardiac SciencesUniversity of Calgary Calgary AB Canada
- Stephenson Cardiac Imaging CentreUniversity of Calgary AB Canada
| | - Frank S. Prato
- Department of Medical BiophysicsSchulich School of Medicine & Dentistry, The University of Western Ontario London Ontario Canada
| | - Maria Drangova
- Department of Medical BiophysicsSchulich School of Medicine & Dentistry, The University of Western Ontario London Ontario Canada
- Imaging Research Laboratories, Robarts Research InstituteSchulich School of Medicine & Dentistry, The University of Western Ontario London Ontario Canada
| | | | - Pablo Nery
- Division of Cardiology, Department of MedicineUniversity of Ottawa Heart Institute Ottawa ON Canada
| | - Stephen B. Wilton
- Department of Cardiac SciencesUniversity of Calgary Calgary AB Canada
| | - Allan Skanes
- Department of MedicineUniversity of Western Ontario London ON Canada
| | - James A. White
- Department of Cardiac SciencesUniversity of Calgary Calgary AB Canada
- Stephenson Cardiac Imaging CentreUniversity of Calgary AB Canada
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31
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Liu L, Alizadeh K, Donnelly SC, Dassanayake P, Hou TT, McGirr R, Thompson RT, Prato FS, Gelman N, Hoffman L, Goldhawk DE. MagA expression attenuates iron export activity in undifferentiated multipotent P19 cells. PLoS One 2019; 14:e0217842. [PMID: 31170273 PMCID: PMC6553743 DOI: 10.1371/journal.pone.0217842] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 05/20/2019] [Indexed: 12/21/2022] Open
Abstract
Magnetic resonance imaging (MRI) is a non-invasive imaging modality used in longitudinal cell tracking. Previous studies suggest that MagA, a putative iron transport protein from magnetotactic bacteria, is a useful gene-based magnetic resonance contrast agent. Hemagglutinin-tagged MagA was stably expressed in undifferentiated embryonic mouse teratocarcinoma, multipotent P19 cells to provide a suitable model for tracking these cells during differentiation. Western blot and immunocytochemistry confirmed the expression and membrane localization of MagA in P19 cells. Surprisingly, elemental iron analysis using inductively-coupled plasma mass spectrometry revealed significant iron uptake in both parental and MagA-expressing P19 cells, cultured in the presence of iron-supplemented medium. Withdrawal of this extracellular iron supplement revealed unexpected iron export activity in P19 cells, which MagA expression attenuated. The influence of iron supplementation on parental and MagA-expressing cells was not reflected by longitudinal relaxation rates. Measurement of transverse relaxation rates (R2* and R2) reflected changes in total cellular iron content but did not clearly distinguish MagA-expressing cells from the parental cell type, despite significant differences in the uptake and retention of total cellular iron. Unlike other cell types, the reversible component R2′ (R2* ‒ R2) provided only a moderately strong correlation to amount of cellular iron, normalized to amount of protein. This is the first report to characterize MagA expression in a previously unrecognized iron exporting cell type. The interplay between contrast gene expression and systemic iron metabolism substantiates the potential for diverting cellular iron toward the formation of a novel iron compartment, however rudimentary when using a single magnetotactic bacterial gene expression system like magA. Since relatively few mammalian cells export iron, the P19 cell line provides a tractable model of ferroportin activity, suitable for magnetic resonance analysis of key iron-handling activities and their influence on gene-based MRI contrast.
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Affiliation(s)
- Linshan Liu
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
- Medical Biophysics, Western University, London, Ontario, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Ontario, Canada
| | - Kobra Alizadeh
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
- Medical Biophysics, Western University, London, Ontario, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Ontario, Canada
| | - Sarah C. Donnelly
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Ontario, Canada
- Microbiology and Immunology, Western University, London, Ontario, Canada
| | - Praveen Dassanayake
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
- Medical Biophysics, Western University, London, Ontario, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Ontario, Canada
| | - Tian Tian Hou
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
| | - Rebecca McGirr
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
| | - R. Terry Thompson
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
- Medical Biophysics, Western University, London, Ontario, Canada
- Medical Imaging, Western University, London, Ontario, Canada
- Physics and Astronomy, Western University, London, Ontario, Canada
| | - Frank S. Prato
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
- Medical Biophysics, Western University, London, Ontario, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Ontario, Canada
- Medical Imaging, Western University, London, Ontario, Canada
- Physics and Astronomy, Western University, London, Ontario, Canada
| | - Neil Gelman
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
- Medical Biophysics, Western University, London, Ontario, Canada
- Medical Imaging, Western University, London, Ontario, Canada
| | - Lisa Hoffman
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
- Medical Biophysics, Western University, London, Ontario, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Ontario, Canada
- Anatomy and Cell Biology, Western University, London, Ontario, Canada
| | - Donna E. Goldhawk
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
- Medical Biophysics, Western University, London, Ontario, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Ontario, Canada
- * E-mail:
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32
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Mouawad M, Biernaski H, Brackstone M, Lock M, Yaremko B, Sexton T, Yu E, Dinniwell RE, Lynn K, Hajdok G, Prato FS, Thompson RT, Gelman N, Gaede S. Reducing the dose of gadolinium-based contrast agents for DCE-MRI guided SBRT: The effects on inter and intra observer variability for preoperative target volume delineation in early stage breast cancer patients. Radiother Oncol 2019; 131:60-65. [PMID: 30773188 DOI: 10.1016/j.radonc.2018.11.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 10/26/2018] [Accepted: 11/29/2018] [Indexed: 11/27/2022]
Abstract
BACKGROUND AND PURPOSE This study aimed to determine the effects of reducing the dose of contrast agent (CA) in a DCE-MRI scan on inter- and intra-observer variability in the context of MRI-guided target volume delineation for stereotactic body radiation therapy of early stage breast cancer patients. This is in hopes of reducing risks to patients due to findings of residual CA in brain and bone. MATERIALS AND METHODS Twenty-three patients receiving neoadjuvant radiation therapy were enrolled. Five observers delineated the gross target volume (GTV) using DCE-MRI for guidance. 14/23 patients received the full clinical dose of CA and 9/23 received half. Clinical target volumes (CTV) were created through a 0.5 cm uniform expansion. Several metrics were used to quantify the inter and intra-observer reliability including differences in delineation volume and the reliability coefficient. RESULTS There were no significant differences in the volume, though half contrast patients had a lower median for both the GTV and CTV (difference of 0.26 cm3 and 1.27 cm3, respectively). All indicated a high degree of agreement between and within observers for both dose groups. However, the full dose group had a greater inter-observer variability, most likely due to the full CA causing more pronounced enhancement in the periphery. CONCLUSIONS Reducing the dose of contrast agent did not significantly alter inter- or intra-observer variability. These results have prompted our centre to reduce the dose of gadolinium in all patients enrolled in the SIGNAL trial.
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Affiliation(s)
| | | | - Muriel Brackstone
- Medical Biophysics, Western University, London, Canada; Lawson Health Research Institute, London, Canada; London Health Sciences Centre, London, Canada; Department of Oncology, Western University, London, Canada.
| | - Michael Lock
- London Health Sciences Centre, London, Canada; Department of Oncology, Western University, London, Canada.
| | - Brian Yaremko
- London Health Sciences Centre, London, Canada; Department of Oncology, Western University, London, Canada.
| | - Tracy Sexton
- London Health Sciences Centre, London, Canada; Department of Oncology, Western University, London, Canada.
| | - Edward Yu
- London Health Sciences Centre, London, Canada; Department of Oncology, Western University, London, Canada.
| | - Robert E Dinniwell
- London Health Sciences Centre, London, Canada; Department of Oncology, Western University, London, Canada.
| | - Kalan Lynn
- London Health Sciences Centre, London, Canada.
| | | | - Frank S Prato
- Medical Biophysics, Western University, London, Canada; Lawson Health Research Institute, London, Canada.
| | - Robert Terry Thompson
- Medical Biophysics, Western University, London, Canada; Lawson Health Research Institute, London, Canada.
| | - Neil Gelman
- Medical Biophysics, Western University, London, Canada; Lawson Health Research Institute, London, Canada.
| | - Stewart Gaede
- Medical Biophysics, Western University, London, Canada; Lawson Health Research Institute, London, Canada; London Health Sciences Centre, London, Canada.
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33
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Prato FS, Pavlosky WF, Foster SC, Thiessen JD, Beaujot RP. Screening for Dementia Caused by Modifiable Lifestyle Choices Using Hybrid PET/MRI. J Alzheimers Dis Rep 2019; 3:31-45. [PMID: 30842996 PMCID: PMC6400112 DOI: 10.3233/adr-180098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2018] [Indexed: 12/19/2022] Open
Abstract
Significant advances in positron emission tomography (PET) and magnetic resonance imaging (MRI) brain imaging in the early detection of dementia indicate that hybrid PET/MRI would be an effective tool to screen for dementia in the population living with lifestyle risk factors. Here we investigate the associated costs and benefits along with the needed imaging infrastructure. A demographic analysis determined the prevalence of dementia and its incidence. The expected value of the screening program was calculated assuming a sensitivity and specificity of 0.9, a prevalence of 0.1, a QALY factor of 0.348, a willingness to pay $114,000 CAD and the cost per PET/MRI scan of $2,000 CAD. It was assumed that each head PET/MRI could screen 3,000 individuals per year. The prevalence of dementia is increasing by almost two-fold every 20 years due to the increased population at ages where dementia is more prevalent. It has been shown that a five-year delay in the incidence of dementia would decrease the prevalence by some 45%. In Canada, a five-year delay corresponds to a health care savings of $27,000 CAD per subject per year. The expected value for screening was estimated at $23,745 CAD. The number of subjects to be screened per year in Canada, USA, and China between 60 and 79 was 11,405,000. The corresponding number of head-only hybrid PET/MRI systems needed is 3,800. A brain PET/MRI screening program is financially justifiable with respect to health care costs and justifies the continuing development of MRI compatible brain PET technology.
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Affiliation(s)
- Frank S. Prato
- Department of Medical Biophysics, Western University, London, ON, Canada
- Lawson Health Research Institute, London, ON, Canada
- Department of Medical Imaging, Western University, London, ON, Canada
| | - William F. Pavlosky
- Lawson Health Research Institute, London, ON, Canada
- Department of Medical Imaging, Western University, London, ON, Canada
| | | | - Jonathan D. Thiessen
- Department of Medical Biophysics, Western University, London, ON, Canada
- Lawson Health Research Institute, London, ON, Canada
- Department of Medical Imaging, Western University, London, ON, Canada
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34
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El-Sherif O, Xhaferllari I, Sykes J, Butler J, deKemp RA, Renaud J, Yin H, Wilk B, Sullivan R, Pickering JG, Battista J, Wisenberg G, Prato FS, Gaede S. [ 18F]FDG cardiac PET imaging in a canine model of radiation-induced cardiovascular disease associated with breast cancer radiotherapy. Am J Physiol Heart Circ Physiol 2018; 316:H586-H595. [PMID: 30575441 DOI: 10.1152/ajpheart.00273.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Radiotherapy for the treatment of left-sided breast cancer increases the long-term risk of cardiovascular disease. The purpose of the present study was to noninvasively image the progression of radiation-induced cardiac inflammation in a large animal model using a hybrid PET and MRI system. Five canines were imaged using [18F]fluorodeoxyglucose PET to assess changes in myocardial inflammation. All animals were imaged at baseline, 1 wk, and 1, 3, 6, and 12 mo after focused cardiac external beam irradiation with image guidance. Radiation was delivered in a single fraction. The linear quadratic model was used to convert a typical multifractionated heart dose to a corrected single-fraction biologically equivalent dose. Immunohistochemistry was performed on excised left ventricular tissue samples from all five irradiated canines and one nonirradiated control canine to confirm the presence of inflammation. The mean doses delivered to the entire heart, left ventricle, left anterior descending artery, and left circumflex artery were 1.7 ± 0.2, 2.7 ± 0.2, 5.5 ± 0.9, and 1.1 ± 0.4 Gy, respectively. FDG standard uptake values remained persistently elevated compared with baseline (1.1 ± 0.03 vs. 2.6 ± 0.19, P < 0.05). The presence of myocardial inflammation was confirmed histologically and correlated with myocardial dose. This study suggests a global inflammatory response that is persistent up to 12 mo postirradiation. Inflammation PET imaging should be considered in future clinical studies to monitor the early changes in cardiac function that may play a role in the ultimate development of radiation-induced cardiac toxicity. NEW & NOTEWORTHY Using advanced cardiac PET imaging, we have shown the spatial and quantitative relationship between radiation dose deposition and temporal changes in inflammation. We have shown that the progression of radiation-induced cardiac inflammation is immediate and does not subside for up to 1 yr after radiation. Results are presented in a large animal model that closely resembles the size and vessel architecture of humans. The proposed imaging protocol can be easily replicated for clinical use.
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Affiliation(s)
- Omar El-Sherif
- Department of Medical Biophysics, Western University , London, Ontario , Canada.,Department of Physics and Radiation Oncology, London Regional Cancer Program, London, Ontario , Canada
| | - Ilma Xhaferllari
- Department of Medical Biophysics, Western University , London, Ontario , Canada.,Department of Physics and Radiation Oncology, London Regional Cancer Program, London, Ontario , Canada
| | - Jane Sykes
- Thames Valley Veterinary Services , London, Ontario , Canada.,Lawson Health Research Institute , London, Ontario , Canada
| | - John Butler
- Lawson Health Research Institute , London, Ontario , Canada
| | - Robert A deKemp
- National Cardiac PET Centre, University of Ottawa Heart Institute , Ottawa, Ontario , Canada
| | - Jennifer Renaud
- National Cardiac PET Centre, University of Ottawa Heart Institute , Ottawa, Ontario , Canada
| | - Hao Yin
- Robarts Research Institute, London, Ontario, Canada
| | - Ben Wilk
- Department of Medical Biophysics, Western University , London, Ontario , Canada
| | - Rebecca Sullivan
- Department of Medical Biophysics, Western University , London, Ontario , Canada
| | - J Geoffrey Pickering
- Department of Medical Biophysics, Western University , London, Ontario , Canada.,Lawson Health Research Institute , London, Ontario , Canada.,Robarts Research Institute, London, Ontario, Canada.,Division of Cardiology, London Health Sciences Centre , London, Ontario , Canada
| | - Jerry Battista
- Department of Medical Biophysics, Western University , London, Ontario , Canada.,Department of Physics and Radiation Oncology, London Regional Cancer Program, London, Ontario , Canada
| | - Gerald Wisenberg
- Department of Medical Biophysics, Western University , London, Ontario , Canada.,Lawson Health Research Institute , London, Ontario , Canada.,Division of Cardiology, London Health Sciences Centre , London, Ontario , Canada
| | - Frank S Prato
- Department of Medical Biophysics, Western University , London, Ontario , Canada.,Lawson Health Research Institute , London, Ontario , Canada
| | - Stewart Gaede
- Department of Medical Biophysics, Western University , London, Ontario , Canada.,Department of Physics and Radiation Oncology, London Regional Cancer Program, London, Ontario , Canada.,Lawson Health Research Institute , London, Ontario , Canada
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Abstract
We have previously proposed that there are at least two initial molecular transduction mechanisms needed to explain specific and nonspecific biological effects of weak magnetic fields. For the specific effect associated with animal magnetic navigation, the radical pair mechanism is the leading hypothesis; it associates the specialised magnetic sense with the radical pairs located in the eye retina. In contrast to the magnetic sense, nonspecific effects occur through the interaction of magnetic fields with magnetic moments dispersed over the organism. However, it is unlikely that the radical pair mechanism can explain such nonspecific phenomena. In order to explain these, we further develop our physical model for the case of magnetic moments residing in rotating molecules. It is shown that, in some conditions, the precession of the magnetic moments that reside on rotating molecules can be slowed relative to the immediate biophysical structures. In terms of quantum mechanics this corresponds to the mixing of the quantum levels of magnetic moments. Hence this mechanism is called the Level Mixing Mechanism, or the LMM. The results obtained are magnetic field-dependences that are in good agreement with known experiments where biological effects arise in response to the reversal of the magnetic field vector.
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Affiliation(s)
| | - Frank S Prato
- Lawson Health Research Institute, Ontario, N6A 4V2, Canada.
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36
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Cocker MS, Spence JD, Hammond R, deKemp RA, Lum C, Wells G, Bernick J, Hill A, Nagpal S, Stotts G, Alturkustani M, Adeeko A, Yerofeyeva Y, Rayner K, Peterson J, Khan AR, Naidas AC, Garrard L, Yaffe MJ, Leung E, Prato FS, Tardif JC, Beanlands RSB. [18F]-Fluorodeoxyglucose PET/CT imaging as a marker of carotid plaque inflammation: Comparison to immunohistology and relationship to acuity of events. Int J Cardiol 2018; 271:378-386. [PMID: 30007487 DOI: 10.1016/j.ijcard.2018.05.057] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 05/02/2018] [Accepted: 05/17/2018] [Indexed: 11/19/2022]
Abstract
BACKGROUND [18F]-fluorodeoxyglucose (18FDG) uptake imaged with positron emission tomography (PET) and computed tomography (CT) may serve as a biomarker of plaque inflammation. This study evaluated the relationship between carotid plaque 18FDG uptake and a) intraplaque expression of macrophage and macrophage-like cellular CD68 immunohistology; b) intraplaque inflammatory burden using leukocyte-sensitive CD45 immunohistology; c) symptomatic patient presentation; d) time from last cerebrovascular event. METHODS 54 patients scheduled for carotid endarterectomy underwent 18FDG PET/CT imaging. Maximum 18FDG uptake (SUVmax) and tissue-to-blood ratio (TBRmax) was measured for carotid plaques. Quantitative immunohistological analysis of macrophage-like cell expression (CD68) and leukocyte content (CD45) was performed. RESULTS 18FDG uptake was related to CD68 macrophage expression (TBRmax: r = 0.51, p < 0.001), and total-plaque leukocyte CD45 expression (TBRmax: r = 0.632, p = 0.009, p < 0.001). 18FDG TBRmax uptake in carotid plaque associated with patient symptoms was greater than asymptomatic plaque (3.58 ± 1.01 vs. 3.13 ± 1.10, p = 0.008). 18FDG uptake differed between an acuity threshold of <90 days and >90 days (SUVmax:3.15 ± 0.87 vs. 2.52 ± 0.45, p = 0.015). CONCLUSIONS In this CAIN cohort, 18FDG uptake imaged with PET/CT serves a surrogate marker of intraplaque inflammatory macrophage, macrophage-like cell and leukocyte burden. 18FDG uptake is greater in plaque associated with patient symptoms and those with recent cerebrovascular events. Future studies are needed to relate 18FDG uptake and disease progression.
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Affiliation(s)
- Myra S Cocker
- Molecular Function and Imaging Program and the National Cardiac PET Centre, Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
| | - J David Spence
- Stroke Prevention & Atherosclerosis Research Centre, Robarts Research Institute, Western University, London, Ontario, Canada.
| | - Robert Hammond
- Department of Pathology, Western University, London, Ontario, Canada.
| | - Robert A deKemp
- Molecular Function and Imaging Program and the National Cardiac PET Centre, Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
| | - Cheemun Lum
- Department of Radiology, University of Ottawa and The Ottawa Hospital, Ottawa, Ontario, Canada.
| | - George Wells
- Cardiovascular Research Methods Centre, University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
| | - Jordan Bernick
- Cardiovascular Research Methods Centre, University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
| | - Andrew Hill
- Cardiovascular Research Methods Centre, University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
| | - Sudhir Nagpal
- Division of Vascular Surgery, Department of Surgery, University of Ottawa and The Ottawa Hospital, Ottawa, Ontario, Canada.
| | - Grant Stotts
- Division of Neurology, Department of Medicine, University of Ottawa and The Ottawa Hospital, Ottawa, Ontario, Canada.
| | | | - Adebayo Adeeko
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
| | - Yulia Yerofeyeva
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
| | - Katey Rayner
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada.
| | - Joan Peterson
- Cardiovascular Research Methods Centre, University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
| | - Ali R Khan
- Department of Medical Biophysics, Robarts Research Institute, Western University, London, Ontario, Canada.
| | - Ann C Naidas
- Department of Pathology, Western University, London, Ontario, Canada.
| | - Linda Garrard
- Molecular Function and Imaging Program and the National Cardiac PET Centre, Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
| | - Martin J Yaffe
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
| | - Eugene Leung
- Division of Nuclear Medicine, Department of Medicine, University of Ottawa and The Ottawa Hospital, Ottawa, Ontario, Canada.
| | - Frank S Prato
- Lawson Health Research Institute, London, Ontario, Canada.
| | - Jean-Claude Tardif
- Division of Cardiology, Montreal Heart Institute, University of Montreal, Montreal, Quebec, Canada.
| | - Rob S B Beanlands
- Molecular Function and Imaging Program and the National Cardiac PET Centre, Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa, Ontario, Canada; Department of Radiology, University of Ottawa and The Ottawa Hospital, Ottawa, Ontario, Canada; Division of Nuclear Medicine, Department of Medicine, University of Ottawa and The Ottawa Hospital, Ottawa, Ontario, Canada.
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Ssali T, Anazodo UC, Thiessen JD, Prato FS, St. Lawrence K. A Noninvasive Method for Quantifying Cerebral Blood Flow by Hybrid PET/MRI. J Nucl Med 2018. [DOI: 10.2967/jnumed.117.203414] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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Anazodo UC, Finger E, Kwan BYM, Pavlosky W, Warrington JC, Günther M, Prato FS, Thiessen JD, St Lawrence KS. Using simultaneous PET/MRI to compare the accuracy of diagnosing frontotemporal dementia by arterial spin labelling MRI and FDG-PET. Neuroimage Clin 2017; 17:405-414. [PMID: 29159053 PMCID: PMC5683801 DOI: 10.1016/j.nicl.2017.10.033] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 10/24/2017] [Accepted: 10/28/2017] [Indexed: 11/30/2022]
Abstract
Purpose The clinical utility of FDG-PET in diagnosing frontotemporal dementia (FTD) has been well demonstrated over the past decades. On the contrary, the diagnostic value of arterial spin labelling (ASL) MRI - a relatively new technique - in clinical diagnosis of FTD has yet to be confirmed. Using simultaneous PET/MRI, we evaluated the diagnostic performance of ASL in identifying pathological abnormalities in FTD (FTD) to determine whether ASL can provide similar diagnostic value as FDG-PET. Methods ASL and FDG-PET images were compared in 10 patients with FTD and 10 healthy older adults. Qualitative and quantitative measures of diagnostic equivalency were used to determine the diagnostic utility of ASL compared to FDG-PET. Sensitivity, specificity, and inter-rater reliability were calculated for each modality from scores of subjective visual ratings and from analysis of regional mean values in thirteen a priori regions of interest (ROI). To determine the extent of concordance between modalities in each patient, individual statistical maps generated from comparison of each patient to controls were compared between modalities using the Jaccard similarity index (JI). Results Visual assessments revealed lower sensitivity, specificity and inter-rater reliability for ASL (66.67%/62.12%/0.2) compared to FDG-PET (88.43%/90.91%/0.61). Across all regions, ASL performed lower than FDG-PET in discriminating patients from controls (areas under the receiver operating curve: ASL = 0.75 and FDG-PET = 0.87). In all patients, ASL identified patterns of reduced perfusion consistent with FTD, but areas of hypometabolism exceeded hypoperfused areas (group-mean JI = 0.30 ± 0.22). Conclusion This pilot study demonstrated that ASL can detect similar spatial patterns of abnormalities in individual FTD patients compared to FDG-PET, but its sensitivity and specificity for discriminant diagnosis of a patient from healthy individuals remained unmatched to FDG-PET. Further studies at the individual level are required to confirm the clinical role of ASL in FTD management.
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Affiliation(s)
- Udunna C Anazodo
- Lawson Health Research Institute, St Joseph's Health Care, 268 Grosvenor St., London, Ontario N6A 4V2, Canada; Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, Medical Sciences Building, Rm M407, London, Ontario N6A 5C1, Canada.
| | - Elizabeth Finger
- Department of Clinical Neurological Sciences, Western University, 339 Windermere Road, London, Ontario N6A 5A5, Canada.
| | - Benjamin Yin Ming Kwan
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5W9, Canada
| | - William Pavlosky
- Lawson Health Research Institute, St Joseph's Health Care, 268 Grosvenor St., London, Ontario N6A 4V2, Canada; Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5W9, Canada.
| | - James Claude Warrington
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5W9, Canada.
| | - Matthias Günther
- Fraunhofer Institute for Medical Image Computing MEVIS, Am Fallturm 1, 28359 Bremen, Germany.; University Bremen, Faculty 1, Otto-Hahn-Allee 1, 28359 Bremen, Germany.
| | - Frank S Prato
- Lawson Health Research Institute, St Joseph's Health Care, 268 Grosvenor St., London, Ontario N6A 4V2, Canada; Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, Medical Sciences Building, Rm M407, London, Ontario N6A 5C1, Canada.
| | - Jonathan D Thiessen
- Lawson Health Research Institute, St Joseph's Health Care, 268 Grosvenor St., London, Ontario N6A 4V2, Canada; Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, Medical Sciences Building, Rm M407, London, Ontario N6A 5C1, Canada.
| | - Keith S St Lawrence
- Lawson Health Research Institute, St Joseph's Health Care, 268 Grosvenor St., London, Ontario N6A 4V2, Canada; Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, Medical Sciences Building, Rm M407, London, Ontario N6A 5C1, Canada.
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Patrick JC, Terry Thompson R, So A, Butler J, Faul D, Stodilka RZ, Yartsev S, Prato FS, Gaede S. Technical Note: Comparison of megavoltage, dual-energy, and single-energy CT-based μ-maps for a four-channel breast coil in PET/MRI. Med Phys 2017. [PMID: 28622420 DOI: 10.1002/mp.12407] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
PURPOSE The purpose of this study was to describe and evaluate methods for calculating a megavoltage computed tomography (MVCT)-derived MR hardware attenuation map (μ-map) and dual-energy CT (DECT) for 511 keV photons. METHODS Phantom measurements were acquired on a whole-body hybrid PET/MRI system, using a four-channel receive-only MR radiofrequency (RF) breast coil. Two acquisitions were performed: with the phantoms positioned in the four-channel RF breast coil, and without the breast coil. PET attenuation from the breast coil was corrected using three different CT-derived hardware μ-maps: (a) Single-energy CT (SECT), (b) DECT, and (c) MVCT. Each attenuation-corrected (AC) PET volume was evaluated and compared with the acquisition performed without the breast coil. RESULTS The breast coil attenuated PET photons by 10% overall. Threshold values were applied to the SECT μ-map to reduce the effects of metal artifacts, but overcorrection occurred in more highly attenuated regions. The DECT-derived virtual monochromatic image reduced beam-hardening artifacts, but other metal artifacts remained. Despite the remaining metal artifacts in the DECT image, it led to an improvement in the more attenuated regions. The MVCT images appear to be free from metal artifacts leading to an artifact-free μ-map and a further improvement AC-PET images. CONCLUSIONS Our MVCT-based approach for creating μ-maps for MR RF coils greatly reduces artifacts produced by metal in a SECT approach. This eliminates the need for other artifact reduction methods, including the application of a threshold of narrow beam attenuation coefficients, or disassembling hardware to remove high-Z components before imaging with a kilovoltage source.
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Affiliation(s)
- John C Patrick
- London Regional Cancer Program, Physics and Engineering Dept., London, ON, Canada.,Lawson Health Research Institute, London, ON, Canada.,Department of Medical Biophysics, Western University, London, ON, Canada
| | - R Terry Thompson
- Lawson Health Research Institute, London, ON, Canada.,Department of Medical Biophysics, Western University, London, ON, Canada
| | - Aaron So
- Lawson Health Research Institute, London, ON, Canada.,Imaging Laboratories, Robarts Research Institute, London, ON, Canada
| | - John Butler
- Lawson Health Research Institute, London, ON, Canada
| | | | - Robert Z Stodilka
- Lawson Health Research Institute, London, ON, Canada.,Department of Medical Biophysics, Western University, London, ON, Canada
| | - Slav Yartsev
- London Regional Cancer Program, Physics and Engineering Dept., London, ON, Canada.,Lawson Health Research Institute, London, ON, Canada.,Department of Medical Biophysics, Western University, London, ON, Canada
| | - Frank S Prato
- Lawson Health Research Institute, London, ON, Canada.,Department of Medical Biophysics, Western University, London, ON, Canada
| | - Stewart Gaede
- London Regional Cancer Program, Physics and Engineering Dept., London, ON, Canada.,Lawson Health Research Institute, London, ON, Canada.,Department of Medical Biophysics, Western University, London, ON, Canada
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Abstract
During interplanetary flights in the near future, a human organism will be exposed to prolonged periods of a hypomagnetic field that is 10,000 times weaker than that of Earth's. Attenuation of the geomagnetic field occurs in buildings with steel walls and in buildings with steel reinforcement. It cannot be ruled out also that a zero magnetic field might be interesting in biomedical studies and therapy. Further research in the area of hypomagnetic field effects, as shown in this article, is capable of shedding light on a fundamental problem in biophysics-the problem of primary magnetoreception. This review contains, currently, the most extensive bibliography on the biological effects of hypomagnetic field. This includes both a review of known experimental results and the putative mechanisms of magnetoreception and their explanatory power with respect to the hypomagnetic field effects. We show that the measured correlations of the HMF effect with HMF magnitude and inhomogeneity and type and duration of exposure are statistically absent. This suggests that there is no general biophysical MF target similar for different organisms. This also suggests that magnetoreception is not necessarily associated with evolutionary developed specific magnetoreceptors in migrating animals and magnetotactic bacteria. Independently, there is nonspecific magnetoreception that is common for all organisms, manifests itself in very different biological observables as mostly random reactions, and is a result of MF interaction with magnetic moments at a physical level-moments that are present everywhere in macromolecules and proteins and can sometimes transfer the magnetic signal at the level of downstream biochemical events. The corresponding universal mechanism of magnetoreception that has been given further theoretical analysis allows one to determine the parameters of magnetic moments involved in magnetoreception-their gyromagnetic ratio and thermal relaxation time-and so to better understand the nature of MF targets in organisms.
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Affiliation(s)
- Vladimir N. Binhi
- A.M. Prokhorov General Physics Institute, Moscow, Russia
- M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Frank S. Prato
- Lawson Health Research Institute, Ontario, Canada
- University of Western Ontario, Ontario, Canada
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Kali A, Cokic I, Tang R, Dohnalkova A, Kovarik L, Yang HJ, Kumar A, Prato FS, Wood JC, Underhill D, Marbán E, Dharmakumar R. Persistent Microvascular Obstruction After Myocardial Infarction Culminates in the Confluence of Ferric Iron Oxide Crystals, Proinflammatory Burden, and Adverse Remodeling. Circ Cardiovasc Imaging 2017; 9:CIRCIMAGING.115.004996. [PMID: 27903536 DOI: 10.1161/circimaging.115.004996] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 08/26/2016] [Indexed: 02/07/2023]
Abstract
BACKGROUND Emerging evidence indicates that persistent microvascular obstruction (PMO) is more predictive of major adverse cardiovascular events than myocardial infarct (MI) size. But it remains unclear how PMO, a phenomenon limited to the acute/subacute period of MI, drives adverse remodeling in chronic MI setting. We hypothesized that PMO resolves into chronic iron crystals within MI territories, which in turn are proinflammatory and favor adverse remodeling post-MI. METHODS AND RESULTS Canines (n=40) were studied with cardiac magnetic resonance imaging to characterize the spatiotemporal relationships among PMO, iron deposition, infarct resorption, and left ventricular remodeling between day 7 (acute) and week 8 (chronic) post-MI. Histology was used to assess iron deposition and to examine relationships between iron content with macrophage infiltration, proinflammatory cytokine synthesis, and matrix metalloproteinase activation. Atomic resolution transmission electron microscopy was used to determine iron crystallinity, and energy-dispersive X-ray spectroscopy was used to identify the chemical composition of the iron composite. PMO with or without reperfusion hemorrhage led to chronic iron deposition, and the extent of this deposition was strongly related to PMO volume (r>0.8). Iron deposits were found within macrophages as aggregates of nanocrystals (≈2.5 nm diameter) in the ferric state. Extent of iron deposits was strongly correlated with proinflammatory burden, collagen-degrading enzyme activity, infarct resorption, and adverse structural remodeling (r>0.5). CONCLUSIONS Crystallized iron deposition from PMO is directly related to proinflammatory burden, infarct resorption, and adverse left ventricular remodeling in the chronic phase of MI in canines. Therapeutic strategies to combat adverse remodeling could potentially benefit from taking into account the chronic iron-driven inflammatory process.
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Affiliation(s)
- Avinash Kali
- From the Cedars-Sinai Medical Center, Los Angeles, CA (A.K., I.C., R.T., H.-J.Y., A.K., D.U., E.M., R.D.); University of California, Los Angeles (A.K., H.-J.Y., D.U., E.M., R.D.); Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, Richland, WA (A.D., L.K.); Lawson Health Research Institute, University of Western Ontario, London, Canada (F.S.P.); and Children's Hospital Los Angeles, CA (J.C.W.)
| | - Ivan Cokic
- From the Cedars-Sinai Medical Center, Los Angeles, CA (A.K., I.C., R.T., H.-J.Y., A.K., D.U., E.M., R.D.); University of California, Los Angeles (A.K., H.-J.Y., D.U., E.M., R.D.); Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, Richland, WA (A.D., L.K.); Lawson Health Research Institute, University of Western Ontario, London, Canada (F.S.P.); and Children's Hospital Los Angeles, CA (J.C.W.)
| | - Richard Tang
- From the Cedars-Sinai Medical Center, Los Angeles, CA (A.K., I.C., R.T., H.-J.Y., A.K., D.U., E.M., R.D.); University of California, Los Angeles (A.K., H.-J.Y., D.U., E.M., R.D.); Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, Richland, WA (A.D., L.K.); Lawson Health Research Institute, University of Western Ontario, London, Canada (F.S.P.); and Children's Hospital Los Angeles, CA (J.C.W.)
| | - Alice Dohnalkova
- From the Cedars-Sinai Medical Center, Los Angeles, CA (A.K., I.C., R.T., H.-J.Y., A.K., D.U., E.M., R.D.); University of California, Los Angeles (A.K., H.-J.Y., D.U., E.M., R.D.); Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, Richland, WA (A.D., L.K.); Lawson Health Research Institute, University of Western Ontario, London, Canada (F.S.P.); and Children's Hospital Los Angeles, CA (J.C.W.)
| | - Libor Kovarik
- From the Cedars-Sinai Medical Center, Los Angeles, CA (A.K., I.C., R.T., H.-J.Y., A.K., D.U., E.M., R.D.); University of California, Los Angeles (A.K., H.-J.Y., D.U., E.M., R.D.); Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, Richland, WA (A.D., L.K.); Lawson Health Research Institute, University of Western Ontario, London, Canada (F.S.P.); and Children's Hospital Los Angeles, CA (J.C.W.)
| | - Hsin-Jung Yang
- From the Cedars-Sinai Medical Center, Los Angeles, CA (A.K., I.C., R.T., H.-J.Y., A.K., D.U., E.M., R.D.); University of California, Los Angeles (A.K., H.-J.Y., D.U., E.M., R.D.); Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, Richland, WA (A.D., L.K.); Lawson Health Research Institute, University of Western Ontario, London, Canada (F.S.P.); and Children's Hospital Los Angeles, CA (J.C.W.)
| | - Andreas Kumar
- From the Cedars-Sinai Medical Center, Los Angeles, CA (A.K., I.C., R.T., H.-J.Y., A.K., D.U., E.M., R.D.); University of California, Los Angeles (A.K., H.-J.Y., D.U., E.M., R.D.); Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, Richland, WA (A.D., L.K.); Lawson Health Research Institute, University of Western Ontario, London, Canada (F.S.P.); and Children's Hospital Los Angeles, CA (J.C.W.)
| | - Frank S Prato
- From the Cedars-Sinai Medical Center, Los Angeles, CA (A.K., I.C., R.T., H.-J.Y., A.K., D.U., E.M., R.D.); University of California, Los Angeles (A.K., H.-J.Y., D.U., E.M., R.D.); Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, Richland, WA (A.D., L.K.); Lawson Health Research Institute, University of Western Ontario, London, Canada (F.S.P.); and Children's Hospital Los Angeles, CA (J.C.W.)
| | - John C Wood
- From the Cedars-Sinai Medical Center, Los Angeles, CA (A.K., I.C., R.T., H.-J.Y., A.K., D.U., E.M., R.D.); University of California, Los Angeles (A.K., H.-J.Y., D.U., E.M., R.D.); Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, Richland, WA (A.D., L.K.); Lawson Health Research Institute, University of Western Ontario, London, Canada (F.S.P.); and Children's Hospital Los Angeles, CA (J.C.W.)
| | - David Underhill
- From the Cedars-Sinai Medical Center, Los Angeles, CA (A.K., I.C., R.T., H.-J.Y., A.K., D.U., E.M., R.D.); University of California, Los Angeles (A.K., H.-J.Y., D.U., E.M., R.D.); Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, Richland, WA (A.D., L.K.); Lawson Health Research Institute, University of Western Ontario, London, Canada (F.S.P.); and Children's Hospital Los Angeles, CA (J.C.W.)
| | - Eduardo Marbán
- From the Cedars-Sinai Medical Center, Los Angeles, CA (A.K., I.C., R.T., H.-J.Y., A.K., D.U., E.M., R.D.); University of California, Los Angeles (A.K., H.-J.Y., D.U., E.M., R.D.); Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, Richland, WA (A.D., L.K.); Lawson Health Research Institute, University of Western Ontario, London, Canada (F.S.P.); and Children's Hospital Los Angeles, CA (J.C.W.)
| | - Rohan Dharmakumar
- From the Cedars-Sinai Medical Center, Los Angeles, CA (A.K., I.C., R.T., H.-J.Y., A.K., D.U., E.M., R.D.); University of California, Los Angeles (A.K., H.-J.Y., D.U., E.M., R.D.); Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, Richland, WA (A.D., L.K.); Lawson Health Research Institute, University of Western Ontario, London, Canada (F.S.P.); and Children's Hospital Los Angeles, CA (J.C.W.).
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Prato FS, Binhi VN. Response to comments by Frank Barnes and Ben Greenebaum on “A physical mechanism of magnetoreception: Extension and analysis”. Bioelectromagnetics 2017; 38:324-325. [DOI: 10.1002/bem.22040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 01/29/2017] [Indexed: 11/11/2022]
Affiliation(s)
- Frank S. Prato
- Lawson Health Research InstituteLondonCanada
- University of Western OntarioLondonCanada
| | - Vladimir N. Binhi
- Prokhorov General Physics InstituteMoscowRussian Federation
- Lomonosov Moscow State UniversityMoscowRussian Federation
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Yang HJ, Dey D, Sykes J, Klein M, Butler J, Kovacs MS, Sobczyk O, Sharif B, Bi X, Kali A, Cokic I, Tang R, Yumul R, Conte AH, Tsaftaris SA, Tighiouart M, Li D, Slomka PJ, Berman DS, Prato FS, Fisher JA, Dharmakumar R. Arterial CO 2 as a Potent Coronary Vasodilator: A Preclinical PET/MR Validation Study with Implications for Cardiac Stress Testing. J Nucl Med 2017; 58:953-960. [PMID: 28254864 DOI: 10.2967/jnumed.116.185991] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 01/31/2017] [Indexed: 11/16/2022] Open
Abstract
Myocardial blood flow (MBF) is the critical determinant of cardiac function. However, its response to increases in partial pressure of arterial CO2 (PaCO2), particularly with respect to adenosine, is not well characterized because of challenges in blood gas control and limited availability of validated approaches to ascertain MBF in vivo. Methods: By prospectively and independently controlling PaCO2 and combining it with 13N-ammonia PET measurements, we investigated whether a physiologically tolerable hypercapnic stimulus (∼25 mm Hg increase in PaCO2) can increase MBF to that observed with adenosine in 3 groups of canines: without coronary stenosis, subjected to non-flow-limiting coronary stenosis, and after preadministration of caffeine. The extent of effect on MBF due to hypercapnia was compared with adenosine. Results: In the absence of stenosis, mean MBF under hypercapnia was 2.1 ± 0.9 mL/min/g and adenosine was 2.2 ± 1.1 mL/min/g; these were significantly higher than at rest (0.9 ± 0.5 mL/min/g, P < 0.05) and were not different from each other (P = 0.30). Under left-anterior descending coronary stenosis, MBF increased in response to hypercapnia and adenosine (P < 0.05, all territories), but the effect was significantly lower than in the left-anterior descending coronary territory (with hypercapnia and adenosine; both P < 0.05). Mean perfusion defect volumes measured with adenosine and hypercapnia were significantly correlated (R = 0.85) and were not different (P = 0.12). After preadministration of caffeine, a known inhibitor of adenosine, resting MBF decreased; and hypercapnia increased MBF but not adenosine (P < 0.05). Conclusion: Arterial blood CO2 tension when increased by 25 mm Hg can induce MBF to the same level as a standard dose of adenosine. Prospectively targeted arterial CO2 has the capability to evolve as an alternative to current pharmacologic vasodilators used for cardiac stress testing.
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Affiliation(s)
- Hsin-Jung Yang
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California.,Department of Bioengineering, University of California, Los Angeles, California
| | - Damini Dey
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California.,Department of Bioengineering, University of California, Los Angeles, California
| | - Jane Sykes
- University of Western Ontario, Lawson Health Research Institute, London, Ontario, Canada
| | - Michael Klein
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - John Butler
- University of Western Ontario, Lawson Health Research Institute, London, Ontario, Canada
| | - Michael S Kovacs
- University of Western Ontario, Lawson Health Research Institute, London, Ontario, Canada
| | - Olivia Sobczyk
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Behzad Sharif
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California
| | - Xiaoming Bi
- MR R&D, Siemens Healthcare, Los Angeles, California
| | - Avinash Kali
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California.,Department of Bioengineering, University of California, Los Angeles, California
| | - Ivan Cokic
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California
| | - Richard Tang
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California
| | - Roya Yumul
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California.,Department of Medicine, University of California, Los Angeles, California
| | - Antonio H Conte
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California
| | - Sotirios A Tsaftaris
- School of Engineering, Institute of Digital Communications, University of Edinburgh, Edinburgh, United Kingdom; and
| | - Mourad Tighiouart
- Biostatistics and Bioinformatics Research Center, Cedars-Sinai Medical Center, Los Angeles, California
| | - Debiao Li
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California.,Department of Bioengineering, University of California, Los Angeles, California
| | - Piotr J Slomka
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California.,Department of Medicine, University of California, Los Angeles, California
| | - Daniel S Berman
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California.,Department of Medicine, University of California, Los Angeles, California
| | - Frank S Prato
- University of Western Ontario, Lawson Health Research Institute, London, Ontario, Canada
| | - Joseph A Fisher
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Rohan Dharmakumar
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California .,Department of Bioengineering, University of California, Los Angeles, California.,Department of Medicine, University of California, Los Angeles, California
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Cokic I, Kali A, Tang R, Yang HJ, Kumar A, Prato FS, Francis J, Marban E, Dharmakumar R. AN UNRESTRAINED PROINFLAMMATORY M1 MACROPHAGE POPULATION INDUCED BY IRON NANOCRYSTALS IMPAIRS MYOCARDIAL HEALING AFTER HEMORRHAGIC INFARCTION. J Am Coll Cardiol 2017. [DOI: 10.1016/s0735-1097(17)34835-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Yang HJ, Dey D, Sykes JM, Butler J, Sharif B, Li D, Tsaftaris S, Bi X, Slomka P, Prato FS, Dharmakumar R. Fast, heart-rate independent, whole-heart, free-breathing, three-dimensional myocardial BOLD MRI at 3T with simultaneous 13N-ammonia PET validation in canines. J Cardiovasc Magn Reson 2016. [PMCID: PMC5032554 DOI: 10.1186/1532-429x-18-s1-w2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Binhi VN, Prato FS. A physical mechanism of magnetoreception: Extension and analysis. Bioelectromagnetics 2016; 38:41-52. [DOI: 10.1002/bem.22011] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 09/18/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Vladimir N. Binhi
- A. M. Prokhorov General Physics Institute; Moscow Russian Federation
- M. V. Lomonosov Moscow State University; Moscow Russian Federation
| | - Frank S. Prato
- Lawson Health Research Institute; London Canada
- University of Western Ontario; London Canada
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Mouawad M, Biernaski H, Brackstone M, Klassen M, Lock M, Prato FS, Thompson RT, Gaede S, Gelman N. Sci-Fri AM: MRI and Diagnostic Imaging - 03: The influence of sampling percentage in deformable registration on kinetic model analysis results in DCE-MRI of the breast. Med Phys 2016. [DOI: 10.1118/1.4961834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Yang HJ, Dey D, Sykes JM, Butler J, Sharif B, Li D, Tsaftaris S, Slomka P, Prato FS, Dharmakumar R. Towards reliable myocardial blood-oxygen-level-dependent (BOLD) CMR using late effects of regadenoson with simultaneous 13n-ammonia pet validation in a whole-body hybrid PET/MR system. Journal of Cardiovascular Magnetic Resonance 2016. [PMCID: PMC5032291 DOI: 10.1186/1532-429x-18-s1-o19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Lee CY, Thompson RT, Prato FS, Goldhawk DE, Gelman N. Investigating the Relationship between Transverse Relaxation Rate (R2) and Interecho Time in MagA-Expressing, Iron-Labeled Cells. Mol Imaging 2015; 14:551-60. [PMID: 26637544 DOI: 10.2310/7290.2015.00027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Reporter gene-based labeling of cells with iron is an emerging method of providing magnetic resonance imaging contrast for long-term cell tracking and monitoring cellular activities. This report investigates 9.4 T nuclear magnetic resonance properties of mammalian cells overexpressing MagA, a putative iron transport protein from magnetotactic bacteria. MagA-expressing MDA-MB-435 cells were cultured in the presence and absence of iron supplementation and compared to the untransfected control. The relationship between the transverse relaxation rate (R2) and interecho time was investigated using the Carr-Purcell-Meiboom-Gill sequence. This relationship was analyzed using a model based on water diffusion in weak magnetic field inhomogeneities (Jensen-Chandra model) as well as a fast-exchange model (Luz-Meiboom model). Increases in R2 with increasing interecho time were larger in the iron-supplemented, MagA-expressing cells compared to other cells. The dependence of R2 on interecho time in these iron-supplemented, MagA-expressing cells was better represented by the Jensen-Chandra model compared to the Luz-Meiboom model, whereas the Luz-Meiboom model performed better for the remaining cell types. Our findings provide an estimate of the distance scale of microscopic magnetic field variations in MagA-expressing cells, which is thought to be related to the size of iron-containing vesicles.
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Burhan AM, Marlatt NM, Palaniyappan L, Anazodo UC, Prato FS. Role of Hybrid Brain Imaging in Neuropsychiatric Disorders. Diagnostics (Basel) 2015; 5:577-614. [PMID: 26854172 PMCID: PMC4728476 DOI: 10.3390/diagnostics5040577] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 11/21/2015] [Accepted: 11/26/2015] [Indexed: 01/09/2023] Open
Abstract
This is a focused review of imaging literature to scope the utility of hybrid brain imaging in neuropsychiatric disorders. The review focuses on brain imaging modalities that utilize hybrid (fusion) techniques to characterize abnormal brain molecular signals in combination with structural and functional changes that have been observed in neuropsychiatric disorders. An overview of clinical hybrid brain imaging technologies for human use is followed by a selective review of the literature that conceptualizes the use of these technologies in understanding basic mechanisms of major neuropsychiatric disorders and their therapeutics. Neuronal network abnormalities are highlighted throughout this review to scope the utility of hybrid imaging as a potential biomarker for each disorder.
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Affiliation(s)
- Amer M Burhan
- St. Joseph's Health Care London, Parkwood Institute, 550 Wellington Road, London, ON N6C 0A7, Canada.
- Department of Psychiatry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON N6C 2R6, Canada.
| | - Nicole M Marlatt
- St. Joseph's Health Care London, Parkwood Institute, 550 Wellington Road, London, ON N6C 0A7, Canada.
| | - Lena Palaniyappan
- Department of Psychiatry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON N6C 2R6, Canada.
| | | | - Frank S Prato
- Lawson Health Research Institute, London, ON N6C 2R5, Canada.
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