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Jiang M, Cao F, Zhang Q, Qi Z, Gao Y, Zhang Y, Song B, Wu C, Li M, Xu Y, Zhang X, Wang Y, Wei M, Ji X. Model-predicted brain temperature computational imaging by multimodal noninvasive functional neuromonitoring of cerebral oxygen metabolism and hemodynamics: MRI-derived and clinical validation. J Cereb Blood Flow Metab 2024:271678X241270485. [PMID: 39129194 DOI: 10.1177/0271678x241270485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
Brain temperature, a crucial yet under-researched neurophysiological parameter, is governed by the equilibrium between cerebral oxygen metabolism and hemodynamics. Therapeutic hypothermia has been demonstrated as an effective intervention for acute brain injuries, enhancing survival rates and prognosis. The success of this treatment hinges on the precise regulation of brain temperature. However, the absence of comprehensive brain temperature monitoring methods during therapy, combined with a limited understanding of human brain heat transmission mechanisms, significantly hampers the advancement of hypothermia-based neuroprotective therapies. Leveraging the principles of bioheat transfer and MRI technology, this study conducted quantitative analyses of brain heat transfer during mild hypothermia therapy. Utilizing MRI, we reconstructed brain structures, estimated cerebral blood flow and oxygen consumption parameters, and developed a brain temperature calculation model founded on bioheat transfer theory. Employing computational cerebral hemodynamic simulation analysis, we established an intracranial arterial fluid dynamics model to predict brain temperature variations across different therapeutic hypothermia modalities. We introduce a noninvasive, spatially resolved, and optimized mathematical bio-heat model that synergizes model-predicted and MRI-derived data for brain temperature prediction and imaging. Our findings reveal that the brain temperature images generated by our model reflect distinct spatial variations across individual participants, aligning with experimentally observed temperatures.
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Affiliation(s)
- Miaowen Jiang
- Beijing Institute for Brain Disorders, Capital Medical University, Beijing, 100069, China
| | - Fuzhi Cao
- School of Engineering Medicine, Beihang University, Beijing 100083, China
| | - Qihan Zhang
- Department of Neurology and Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Zhengfei Qi
- Beijing Institute for Brain Disorders, Capital Medical University, Beijing, 100069, China
| | - Yuan Gao
- School of Engineering Medicine, Beihang University, Beijing 100083, China
| | - Yang Zhang
- Department of Neurology and Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Baoyin Song
- Department of Neurology and Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Chuanjie Wu
- Department of Neurology and Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Ming Li
- China-America Institute of Neuroscience and Beijing Institute of Geriatrics, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Yongbo Xu
- Clinical College of Neurology, Neurosurgery and Neurorehabilitation, Tianjin Medical University, Tianjin 300203, China
| | - Xin Zhang
- Brainnetome Center, Laboratory of Brain Atlas and Brain-inspired Intelligence, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
| | - Yuan Wang
- Department of Neurology and Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Ming Wei
- Beijing Institute for Brain Disorders, Capital Medical University, Beijing, 100069, China
- Clinical College of Neurology, Neurosurgery and Neurorehabilitation, Tianjin Medical University, Tianjin 300203, China
- Tianjin University, Tianjin Huanhu Hospital, Tianjin 300203, China
| | - Xunming Ji
- Beijing Institute for Brain Disorders, Capital Medical University, Beijing, 100069, China
- Department of Neurology and Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
- China-America Institute of Neuroscience and Beijing Institute of Geriatrics, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
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Salvagno M, Geraldini F, Coppalini G, Robba C, Gouvea Bogossian E, Annoni F, Vitali E, Sterchele ED, Balestra C, Taccone FS. The Impact of Inotropes and Vasopressors on Cerebral Oxygenation in Patients with Traumatic Brain Injury and Subarachnoid Hemorrhage: A Narrative Review. Brain Sci 2024; 14:117. [PMID: 38391692 PMCID: PMC10886736 DOI: 10.3390/brainsci14020117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 01/17/2024] [Accepted: 01/22/2024] [Indexed: 02/24/2024] Open
Abstract
Traumatic brain injury (TBI) and subarachnoid hemorrhage (SAH) are critical neurological conditions that necessitate specialized care in the Intensive Care Unit (ICU). Managing cerebral perfusion pressure (CPP) and mean arterial pressure (MAP) is of primary importance in these patients. To maintain targeted MAP and CPP, vasopressors and/or inotropes are commonly used. However, their effects on cerebral oxygenation are not fully understood. The aim of this review is to provide an up-to date review regarding the current uses and pathophysiological issues related to the use of vasopressors and inotropes in TBI and SAH patients. According to our findings, despite achieving similar hemodynamic parameters and CPP, the effects of various vasopressors and inotropes on cerebral oxygenation, local CBF and metabolism are heterogeneous. Therefore, a more accurate understanding of the cerebral activity of these medications is crucial for optimizing patient management in the ICU setting.
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Affiliation(s)
- Michele Salvagno
- Department of Intensive Care, Hôpital Universitaire de Bruxelles (HUB), 1070 Brussels, Belgium
| | - Federico Geraldini
- Department of Anesthesia and Intensive Care, Ospedale Università di Padova, 35128 Padova, Italy
| | - Giacomo Coppalini
- Department of Anesthesia and Intensive Care, Humanitas Clinical and Research Center, 20089 Milano, Italy
- Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, 20072 Milano, Italy
| | - Chiara Robba
- Anaesthesia and Intensive Care, IRCCS Policlinico San Martino, 16132 Genova, Italy
- Dipartimento di Scienze Chirurgiche Diagnostiche e Integrate, Università di Genova, 16132 Genova, Italy
| | - Elisa Gouvea Bogossian
- Department of Intensive Care, Hôpital Universitaire de Bruxelles (HUB), 1070 Brussels, Belgium
| | - Filippo Annoni
- Department of Intensive Care, Hôpital Universitaire de Bruxelles (HUB), 1070 Brussels, Belgium
| | - Eva Vitali
- Department of Intensive Care, Hôpital Universitaire de Bruxelles (HUB), 1070 Brussels, Belgium
| | - Elda Diletta Sterchele
- Department of Intensive Care, Hôpital Universitaire de Bruxelles (HUB), 1070 Brussels, Belgium
| | - Costantino Balestra
- Department Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), 1160 Brussels, Belgium
- Anatomical Research and Clinical Studies, Vrije Universiteit Brussels (VUB), 1090 Brussels, Belgium
- DAN Europe Research Division (Roseto-Brussels), 1160 Brussels, Belgium
- Motor Sciences Department, Physical Activity Teaching Unit, Université Libre de Bruxelles (ULB), 1050 Brussels, Belgium
| | - Fabio Silvio Taccone
- Department of Intensive Care, Hôpital Universitaire de Bruxelles (HUB), 1070 Brussels, Belgium
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Klement RJ, Joos FT, Reuss-Borst MA, Kämmerer U. Measurement of body composition by DXA, BIA, Leg-to-leg BIA and near-infrared spectroscopy in breast cancer patients - comparison of the four methods. Clin Nutr ESPEN 2023; 54:443-452. [PMID: 36963892 DOI: 10.1016/j.clnesp.2023.02.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 02/15/2023] [Indexed: 02/25/2023]
Abstract
BACKGROUND & AIMS Body composition plays a crucial role in therapy adherence and the prognosis of cancer patients. The aim of this work was to compare four measurement methods for determining body composition regarding their validity, reliability and practicability in order to be able to draft a practical recommendation as to which method is most suitable as a standard measurement method in oncology. METHODS Fat mass (FM) and fat-free mass (FFM) was estimated for 100 breast cancer patients with ages of 18-70 years during a defined 20-week inpatient and outpatient rehabilitation process after primary therapy or follow-up rehabilitation. The four methods used were dual energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA), leg-to-leg BIA and near-infrared spectroscopy (NIRS). At baseline (t0) and after 20 weeks (t20) the agreement between the four body composition analysis methods was quantified by pairwise method comparisons using Bland-Altman bias and limits of agreement estimates, t-tests and Lin's concordance correlation coefficients (CCCs). RESULTS CCCs and Bland-Altman plots indicated that DXA and BIA, DXA and NIRS as well as BIA and NIRS showed an excellent agreement concerning FM estimation at both time points (CCC>0.9). In contrast, no methods agreed with a CCC higher than 0.9 with respect to FFM estimation. However, most estimates were also significantly different between two methods, except for BIA and NIRS which yielded comparable FFM and FM estimates at both time points, albeit with large 95% limits of agreement intervals. The agreement between DXA and BIA was best in the lowest BMI tertile and worsened as BMI increased. Significant differences were also found for FFM changes measured with DXA versus BIA (mean difference -0.4 kg, p = 0.0049), DXA versus to Leg-to-leg BIA (-0.6 kg, p = 0.00073) and for FM changes measured with DXA versus Leg-to-leg BIA (0.5 kg, p = 0.0011). CONCLUSIONS For accurate and valid body composition estimates, Leg-to-leg BIA cannot be recommended due to its significant underestimation of FM or significant overestimation of FFM, respectively. BIA and NIRS results showed good agreement with the gold standard DXA. Therefore both measurement methods appear to be very well suitable to assess body composition of oncological patients and should be used more frequently on a routine basis to monitor the body composition of breast cancer patients.
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Affiliation(s)
- Rainer J Klement
- Department of Radiation Oncology, Leopoldina Hospital Schweinfurt, Schweinfurt, Germany.
| | - Fabian T Joos
- Department of Anesthesiology, Regional Clinic Holding RKH GmbH - Ludwigsburg, Germany.
| | - Monika A Reuss-Borst
- Hescuro Clinics, Center for Rehabilitation and Prevention, Bad Bocklet, Germany.
| | - Ulrike Kämmerer
- Department of Obstetrics and Gynecology, University Hospital of Würzburg, Würzburg, Germany.
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Hashem M, Wu Y, Dunn JF. The Effect of Hypercapnia on Cortical Metabolic Rate and Mitochondrial Redox Status. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1438:15-20. [PMID: 37845433 DOI: 10.1007/978-3-031-42003-0_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2023]
Abstract
Hypercapnia is commonly used as a vasodilatory stimulus in both basic and clinical research. There have been conflicting reports about whether cerebral metabolic rate of oxygen (CMRO2) is maintained at normal levels during increases of cerebral blood flow (CBF) and oxygen delivery caused by hypercapnia.This study aims to provide insight into how hypercapnia may impact CMRO2 and brain mitochondrial function. We introduce data from mouse cortex collected with a novel multimodality system which combines MRI and near-infrared spectroscopy (NIRS). We quantify CBF, tissue oxygen saturation (StO2), oxidation state of the mitochondrial enzyme cytochrome c oxidase (CCO), and CMRO2.During hypercapnia, CMRO2 did not change while CBF, StO2, and the oxidation state of CCO increased significantly. This paper supports the conclusion that hypercapnia does not change CMRO2. It also introduces the application of a multimodal NIRS-MRI system which enables non-invasive quantification of CMRO2, and other physiological variables, in the cerebral cortex of mouse models.
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Affiliation(s)
- Mada Hashem
- Department of Radiology, University of Calgary, Calgary, AB, Canada.
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.
- Experimental Imaging Centre, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
| | - Ying Wu
- Department of Radiology, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Experimental Imaging Centre, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Jeff F Dunn
- Department of Radiology, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Experimental Imaging Centre, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
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Hashem M, Shafqat Q, Wu Y, Rho JM, Dunn JF. Abnormal Oxidative Metabolism in the Cuprizone Mouse Model of Demyelination: an in vivo NIRS-MRI Study. Neuroimage 2022; 250:118935. [PMID: 35091079 DOI: 10.1016/j.neuroimage.2022.118935] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 01/19/2022] [Accepted: 01/24/2022] [Indexed: 12/11/2022] Open
Abstract
Disruptions in oxidative metabolism may occur in multiple sclerosis and other demyelinating neurological diseases. The impact of demyelination on metabolic rate is also not understood. It is possible that mitochondrial damage may be associated with many such neurological disorders. To study oxidative metabolism with one model of demyelination, we implemented a novel multimodal imaging technique combining Near-Infrared Spectroscopy (NIRS) and MRI to cuprizone mouse model. The cuprizone model is used to study demyelination and may be associated with inhibition of mitochondrial function. Cuprizone mice showed reduced oxygen extraction fraction (-39.1%, p≤0.001), increased tissue oxygenation (6.4%, p≤0.001), and reduced cerebral metabolic rate of oxygen in cortical gray matter (-62.1%, p≤0.001). These changes resolved after the cessation of cuprizone exposure and partial remyelination. A decrease in hemoglobin concentration (-34.4%, p≤0.001), but no change in cerebral blood flow were also observed during demyelination. The oxidized state of the mitochondrial enzyme, Cytochrome C Oxidase (CCO) increased (46.3%, p≤0.001) while the reduced state decreased (-34.4%, p≤0.05) significantly in cuprizone mice. The total amount of CCO did not change significantly during cuprizone exposure. Total CCO did decline after recovery both in control (-23.1%, p≤0.01) and cuprizone (-28.8%, p≤0.001) groups which may relate to age. A reduction in the magnetization transfer ratio, indicating demyelination, was found in the cuprizone group in the cerebral cortex (-3.2%, p≤0.01) and corpus callosum (-5.5%, p≤0.001). In summary, we were able to detect evidence of altered CCO metabolism during cuprizone exposure, consistent with a mitochondrial defect. We observed increased oxygenation and reduced metabolic rate associated with reduced myelination in the gray and white matter. The novel multimodal imaging technique applied here shows promise for noninvasively assessing parameters associated with oxidative metabolism in both mouse models of neurological disease and for translation to study oxidative metabolism in the human brain.
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Affiliation(s)
- Mada Hashem
- Biomedical Engineering Graduate Program, University of Calgary, Calgary, Alberta, Canada T2N 4N1; Department of Radiology, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada, T2N 4N1; Hotchkiss Brain Institute, University of Calgary, Alberta, Canada, T2N 4N1; Experimental Imaging Centre, Cumming School of Medicine, University of Calgary, Alberta, Canada, T2N 4N1
| | - Qandeel Shafqat
- Department of Radiology, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada, T2N 4N1; Hotchkiss Brain Institute, University of Calgary, Alberta, Canada, T2N 4N1; Experimental Imaging Centre, Cumming School of Medicine, University of Calgary, Alberta, Canada, T2N 4N1
| | - Ying Wu
- Department of Radiology, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada, T2N 4N1; Hotchkiss Brain Institute, University of Calgary, Alberta, Canada, T2N 4N1; Experimental Imaging Centre, Cumming School of Medicine, University of Calgary, Alberta, Canada, T2N 4N1
| | - Jong M Rho
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada, T2N 4N1
| | - Jeff F Dunn
- Department of Radiology, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada, T2N 4N1; Hotchkiss Brain Institute, University of Calgary, Alberta, Canada, T2N 4N1; Experimental Imaging Centre, Cumming School of Medicine, University of Calgary, Alberta, Canada, T2N 4N1.
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6
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Li C, Torres VC, He Y, Xu X, Basheer Y, Papavasiliou G, Samkoe KS, Brankov JG, Tichauer KM. Intraoperative Detection of Micrometastases in Whole Excised Lymph Nodes Using Fluorescent Paired-Agent Imaging Principles: Identification of a Suitable Staining and Rinsing Protocol. Mol Imaging Biol 2021; 23:537-549. [PMID: 33591478 DOI: 10.1007/s11307-021-01587-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/18/2021] [Accepted: 02/02/2021] [Indexed: 02/05/2023]
Abstract
PURPOSE Correctly identifying nodal status is recognized as a critical prognostic factor in many cancer types and is essential to guide adjuvant treatment. Currently, surgical removal of lymph nodes followed by pathological examination is commonly performed as a standard-of-care to detect node metastases. However, conventional pathology protocols are time-consuming, yet less than 1 % of lymph node volumes are examined, resulting in a 30-60 % rate of missed micrometastases (0.2-2 mm in size). PROCEDURES This study presents a method to fluorescently stain excised lymph nodes using paired-agent molecular imaging principles, which entail co-administration of a molecular-targeted imaging agent with a suitable control (untargeted) agent, whereby any nonspecific retention of the targeted agent is accounted for by the signal from the control agent. Specifically, it was demonstrated that by dual-needle continuous infusion of either an antibody-based imaging agent pair (epidermal growth factor receptor (EGFR) targeted agent: IRDye-800CW labeled Cetuximab; control agent: IRDye-700DX-IgG) or an Affibody-based pair (EGFR targeted Affibody® agent: ABY-029; control agent IRDYe-700DX carboxylate) at 0.3 ml/min. RESULTS The results demonstrated the possibility to achieve >99 % sensitivity and > 95 % specificity for detection of a single micrometastasis (~0.2 mm diameter) in a whole lymph node within 22 min of tissue processing time. CONCLUSION The detection capabilities offer substantial improvements over existing intraoperative lymph node biopsy methods (e.g., frozen pathology has a micrometastasis sensitivity <20 %).
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Affiliation(s)
- Chengyue Li
- Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, 60616, USA
| | - Veronica C Torres
- Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, 60616, USA
| | - Yusheng He
- Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, 60616, USA
| | - Xiaochun Xu
- Thayer School of Engineering, Dartmouth College, Hanover, NH, 03755, USA
| | - Yusairah Basheer
- Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, 60616, USA
| | - Georgia Papavasiliou
- Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, 60616, USA
| | - Kimberley S Samkoe
- Thayer School of Engineering, Dartmouth College, Hanover, NH, 03755, USA
| | - Jovan G Brankov
- Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, IL, 60616, USA
| | - Kenneth M Tichauer
- Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, 60616, USA.
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Hashem M, Zhang Q, Wu Y, Johnson TW, Dunn JF. Using a multimodal near-infrared spectroscopy and MRI to quantify gray matter metabolic rate for oxygen: A hypothermia validation study. Neuroimage 2019; 206:116315. [PMID: 31669409 DOI: 10.1016/j.neuroimage.2019.116315] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 09/26/2019] [Accepted: 10/24/2019] [Indexed: 11/19/2022] Open
Abstract
Non-invasive quantitative imaging of cerebral oxygen metabolism (CMRO2) in small animal models is crucial to understand the role of oxidative metabolism in healthy and diseased brains. In this study, we developed a multimodal method combining near-infrared spectroscopy (NIRS) and MRI to non-invasively study oxygen delivery and consumption in the cortex of mouse and rat models. The term CASNIRS is proposed to the technique that measures CMRO2 with ASL and NIRS. To determine the reliability of this method, CMRO2 values were compared with reported values measured with other techniques. Also, the sensitivity of the CASNIRS technique to detect changes in CMRO2 in the cortex of the animals was assessed by applying a reduction in core temperature, which is known to reduce CMRO2. Cerebral blood flow (CBF) and CMRO2 were measured in five mice and five rats at a core temperature of 37 °C followed by another measurement at 33 °C. CMRO2 was 7.8 ± 1.8 and 3.7 ± 0.9 (ml/100 g/min, mean ± SD) in mice and rats respectively. These values are in good agreement with reported values measured by 15O PET, 17O NMR, and BOLD fMRI. In hypothermia, we detected a significant decrease of 37% and 32% in CMRO2 in the cortex of mice and rats, respectively. Q10 was calculated to be 3.2 in mice and 2.7 in rats. In this study we showed that it is possible to assess absolute values of metabolic correlates such as CMRO2, CBF and oxygen extraction fraction (OEF) noninvasively in living brain of mice and rats by combining NIRS with MRI. This will open new possibilities for studying brain metabolism in patients as well as the many mouse/rat models of brain disorders.
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Affiliation(s)
- Mada Hashem
- Biomedical Engineering Graduate Program, University of Calgary, Calgary, Alberta, T2N 4N1, Canada; Department of Radiology, Faculty of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada; Hotchkiss Brain Institute, University of Calgary, Alberta, T2N 4N1, Canada; Experimental Imaging Centre, Cumming School of Medicine, University of Calgary, Alberta, T2N 4N1, Canada
| | - Qiong Zhang
- Department of Radiology, Faculty of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada; Hotchkiss Brain Institute, University of Calgary, Alberta, T2N 4N1, Canada; Experimental Imaging Centre, Cumming School of Medicine, University of Calgary, Alberta, T2N 4N1, Canada
| | - Ying Wu
- Department of Radiology, Faculty of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada; Hotchkiss Brain Institute, University of Calgary, Alberta, T2N 4N1, Canada; Experimental Imaging Centre, Cumming School of Medicine, University of Calgary, Alberta, T2N 4N1, Canada
| | - Thomas W Johnson
- Biomedical Engineering Graduate Program, University of Calgary, Calgary, Alberta, T2N 4N1, Canada; Department of Radiology, Faculty of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada; Hotchkiss Brain Institute, University of Calgary, Alberta, T2N 4N1, Canada; Experimental Imaging Centre, Cumming School of Medicine, University of Calgary, Alberta, T2N 4N1, Canada
| | - Jeff F Dunn
- Department of Radiology, Faculty of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada; Hotchkiss Brain Institute, University of Calgary, Alberta, T2N 4N1, Canada; Experimental Imaging Centre, Cumming School of Medicine, University of Calgary, Alberta, T2N 4N1, Canada.
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Kewin M, Rajaram A, Milej D, Abdalmalak A, Morrison L, Diop M, St Lawrence K. Evaluation of hyperspectral NIRS for quantitative measurements of tissue oxygen saturation by comparison to time-resolved NIRS. BIOMEDICAL OPTICS EXPRESS 2019; 10:4789-4802. [PMID: 31565525 PMCID: PMC6757477 DOI: 10.1364/boe.10.004789] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 08/14/2019] [Accepted: 08/14/2019] [Indexed: 05/17/2023]
Abstract
Near-infrared spectroscopy (NIRS) is considered ideal for brain monitoring during preterm infancy because it is non-invasive and provides a continuous measure of tissue oxygen saturation (StO2). Hyperspectral NIRS (HS NIRS) is an inexpensive, quantitative modality that can measure tissue optical properties and oxygen saturation (StO2) by differential spectroscopy. In this study, experiments were conducted using newborn piglets to measure StO2 across a range of oxygenation levels from hyperoxia to hypoxia by HS and time-resolved (TR) NIRS for validation. A strong correlation between StO2 measurements from the two techniques was observed (R2 = 0.98, average slope of 1.02 ± 0.28); however, the HS-NIRS estimates were significantly higher than the corresponding TR-NIRS values. These regression results indicate that HS NIRS could become a clinically feasible method for monitoring StO2 in preterm infants.
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Affiliation(s)
- Matthew Kewin
- Imaging Program, Lawson Health Research Institute, London, Ontario, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, London, Ontario, N6A 5C1, Canada
| | - Ajay Rajaram
- Imaging Program, Lawson Health Research Institute, London, Ontario, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, London, Ontario, N6A 5C1, Canada
| | - Daniel Milej
- Imaging Program, Lawson Health Research Institute, London, Ontario, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, London, Ontario, N6A 5C1, Canada
| | - Androu Abdalmalak
- Imaging Program, Lawson Health Research Institute, London, Ontario, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, London, Ontario, N6A 5C1, Canada
| | - Laura Morrison
- Imaging Program, Lawson Health Research Institute, London, Ontario, N6A 4V2, Canada
| | - Mamadou Diop
- Imaging Program, Lawson Health Research Institute, London, Ontario, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, London, Ontario, N6A 5C1, Canada
| | - Keith St Lawrence
- Imaging Program, Lawson Health Research Institute, London, Ontario, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, London, Ontario, N6A 5C1, Canada
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Evaluating the Role of Reduced Oxygen Saturation and Vascular Damage in Traumatic Brain Injury Using Magnetic Resonance Perfusion-Weighted Imaging and Susceptibility-Weighted Imaging and Mapping. Top Magn Reson Imaging 2016; 24:253-65. [PMID: 26502307 DOI: 10.1097/rmr.0000000000000064] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The cerebral vasculature, along with neurons and axons, is vulnerable to biomechanical insult during traumatic brain injury (TBI). Trauma-induced vascular injury is still an underinvestigated area in TBI research. Cerebral blood flow and metabolism could be important future treatment targets in neural critical care. Magnetic resonance imaging offers a number of key methods to probe vascular injury and its relationship with traumatic hemorrhage, perfusion deficits, venous blood oxygen saturation changes, and resultant tissue damage. They make it possible to image the hemodynamics of the brain, monitor regional damage, and potentially show changes induced in the brain's function not only acutely but also longitudinally following treatment. These methods have recently been used to show that even mild TBI (mTBI) subjects can have vascular abnormalities, and thus they provide a major step forward in better diagnosing mTBI patients.
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Diop M, Kishimoto J, Toronov V, Lee DSC, St. Lawrence K. Development of a combined broadband near-infrared and diffusion correlation system for monitoring cerebral blood flow and oxidative metabolism in preterm infants. BIOMEDICAL OPTICS EXPRESS 2015; 6:3907-18. [PMID: 26504641 PMCID: PMC4605050 DOI: 10.1364/boe.6.003907] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 07/30/2015] [Accepted: 07/31/2015] [Indexed: 05/23/2023]
Abstract
Neonatal neuromonitoring is a major clinical focus of near-infrared spectroscopy (NIRS) and there is an increasing interest in measuring cerebral blood flow (CBF) and oxidative metabolism (CMRO2) in addition to the classic tissue oxygenation saturation (StO2). The purpose of this study was to assess the ability of broadband NIRS combined with diffusion correlation spectroscopy (DCS) to measured changes in StO2, CBF and CMRO2 in preterm infants undergoing pharmaceutical treatment of patent ductus arteriosus. CBF was measured by both DCS and contrast-enhanced NIRS for comparison. No significant difference in the treatment-induced CBF decrease was found between DCS (27.9 ± 2.2%) and NIRS (26.5 ± 4.3%). A reduction in StO2 (70.5 ± 2.4% to 63.7 ± 2.9%) was measured by broadband NIRS, reflecting the increase in oxygen extraction required to maintain CMRO2. This study demonstrates the applicability of broadband NIRS combined with DCS for neuromonitoring in this patient population.
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Affiliation(s)
- Mamadou Diop
- Department of Medical Biophysics, University of Western Ontario, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
| | - Jessica Kishimoto
- Department of Medical Biophysics, University of Western Ontario, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
| | | | - David S. C. Lee
- Department of Neonatology, London Health Sciences Centre, London, ON, Canada
| | - Keith St. Lawrence
- Department of Medical Biophysics, University of Western Ontario, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
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12
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Bakhsheshi MF, Diop M, Morrison LB, St. Lawrence K, Lee TY. Coupling of cerebral blood flow and oxygen consumption during hypothermia in newborn piglets as measured by time-resolved near-infrared spectroscopy: a pilot study. NEUROPHOTONICS 2015; 2:035006. [PMID: 26835481 PMCID: PMC4718069 DOI: 10.1117/1.nph.2.3.035006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 08/18/2015] [Indexed: 06/05/2023]
Abstract
Hypothermia (HT) is a potent neuroprotective therapy that is now widely used in following neurological emergencies, such as neonatal asphyxia. An important mechanism of HT-induced neuroprotection is attributed to the associated reduction in the cerebral metabolic rate of oxygen ([Formula: see text]). Since cerebral circulation and metabolism are tightly regulated, reduction in [Formula: see text] typically results in decreased cerebral blood flow (CBF); it is only under oxidative stress, e.g., hypoxia-ischemia, that oxygen extraction fraction (OEF) deviates from its basal value, which can lead to cerebral dysfunction. As such, it is critical to measure these key physiological parameters during therapeutic HT. This report investigates a noninvasive method of measuring the coupling of [Formula: see text] and CBF under HT and different anesthetic combinations of propofol/nitrous-oxide ([Formula: see text]) that may be used in clinical practice. Both CBF and [Formula: see text] decreased with decreasing temperature, but the OEF remained unchanged, which indicates a tight coupling of flow and metabolism under different anesthetics and over the mild HT temperature range (38°C to 33°C).
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Affiliation(s)
- Mohammad Fazel Bakhsheshi
- Lawson Health Research Institute, Imaging Program, 268 Grosvenor Street, London, Ontario N6A 4V2, Canada
- Robarts Research Institute, Imaging Research Laboratories, 1151 Richmond Street North, London, Ontario N6A 5B7, Canada
| | - Mamadou Diop
- Lawson Health Research Institute, Imaging Program, 268 Grosvenor Street, London, Ontario N6A 4V2, Canada
- Western University, Department of Medical Biophysics, London, Ontario N6A 5C1, Canada
| | - Laura B. Morrison
- Lawson Health Research Institute, Imaging Program, 268 Grosvenor Street, London, Ontario N6A 4V2, Canada
| | - Keith St. Lawrence
- Lawson Health Research Institute, Imaging Program, 268 Grosvenor Street, London, Ontario N6A 4V2, Canada
- Robarts Research Institute, Imaging Research Laboratories, 1151 Richmond Street North, London, Ontario N6A 5B7, Canada
- Western University, Department of Medical Biophysics, London, Ontario N6A 5C1, Canada
| | - Ting-Yim Lee
- Lawson Health Research Institute, Imaging Program, 268 Grosvenor Street, London, Ontario N6A 4V2, Canada
- Robarts Research Institute, Imaging Research Laboratories, 1151 Richmond Street North, London, Ontario N6A 5B7, Canada
- Western University, Department of Medical Biophysics, London, Ontario N6A 5C1, Canada
- Western University, Department of Medical Imaging, London, Ontario N6A 5W9, Canada
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13
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Li C, Wang J, Hu J, Feng Y, Hasegawa K, Peng X, Duan X, Zhao A, Mikitsh JL, Muzykantov VR, Chacko AM, Pryma DA, Dunn SM, Coukos G. Development, optimization, and validation of novel anti-TEM1/CD248 affinity agent for optical imaging in cancer. Oncotarget 2015; 5:6994-7012. [PMID: 25051365 PMCID: PMC4196179 DOI: 10.18632/oncotarget.2188] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Tumor Endothelial Marker-1 (TEM1/CD248) is a tumor vascular marker with high therapeutic and diagnostic potentials. Immuno-imaging with TEM1-specific antibodies can help to detect cancerous lesions, monitor tumor responses, and select patients that are most likely to benefit from TEM1-targeted therapies. In particular, near infrared(NIR) optical imaging with biomarker-specific antibodies can provide real-time, tomographic information without exposing the subjects to radioactivity. To maximize the theranostic potential of TEM1, we developed a panel of all human, multivalent Fc-fusion proteins based on a previously identified single chain antibody (scFv78) that recognizes both human and mouse TEM1. By characterizing avidity, stability, and pharmacokinectics, we identified one fusion protein, 78Fc, with desirable characteristics for immuno-imaging applications. The biodistribution of radiolabeled 78Fc showed that this antibody had minimal binding to normal organs, which have low expression of TEM1. Next, we developed a 78Fc-based tracer and tested its performance in different TEM1-expressing mouse models. The NIR imaging and tomography results suggest that the 78Fc-NIR tracer performs well in distinguishing mouse- or human-TEM1 expressing tumor grafts from normal organs and control grafts in vivo. From these results we conclude that further development and optimization of 78Fc as a TEM1-targeted imaging agent for use in clinical settings is warranted.
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Affiliation(s)
- Chunsheng Li
- Ovarian Cancer Research Center, University of Pennsylvania; These authors contributed equally to this work
| | - Junying Wang
- Ovarian Cancer Research Center, University of Pennsylvania; Department of Immunology, Norman Bethune College of Medicine Jilin University; These authors contributed equally to this work
| | - Jia Hu
- Ovarian Cancer Research Center, University of Pennsylvania
| | - Yi Feng
- Department of Cancer Biology, University of Pennsylvania
| | - Kosei Hasegawa
- Saitama International Medical Center Saitama Medical University
| | - Xiaohui Peng
- Ovarian Cancer Research Center, University of Pennsylvania
| | - Xingmei Duan
- Ovarian Cancer Research Center, University of Pennsylvania
| | - Aizhi Zhao
- Ovarian Cancer Research Center, University of Pennsylvania
| | - John L Mikitsh
- Nuclear Medicine & Clinical Molecular Imaging, Department of Radiology, University of Pennsylvania
| | | | - Ann-Marie Chacko
- Institute for Translational Medicine and Therapeutics, University of Pennsylvania; Nuclear Medicine & Clinical Molecular Imaging, Department of Radiology, University of Pennsylvania
| | - Daniel A Pryma
- Nuclear Medicine & Clinical Molecular Imaging, Department of Radiology, University of Pennsylvania
| | - Steven M Dunn
- Ludwig Cancer Research Center, University of Lausanne
| | - George Coukos
- Ovarian Cancer Research Center, University of Pennsylvania; Ludwig Cancer Research Center, University of Lausanne
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14
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Iwata S, Tachtsidis I, Takashima S, Matsuishi T, Robertson NJ, Iwata O. Dual role of cerebral blood flow in regional brain temperature control in the healthy newborn infant. Int J Dev Neurosci 2014; 37:1-7. [DOI: 10.1016/j.ijdevneu.2014.05.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 05/21/2014] [Accepted: 05/27/2014] [Indexed: 11/25/2022] Open
Affiliation(s)
- Sachiko Iwata
- Centre for Developmental and Cognitive NeuroscienceDepartment of Paediatrics and Child HealthKurume University School of MedicineKurumeFukuokaJapan
- Institute for Women's HealthUniversity College LondonLondonUK
| | - Ilias Tachtsidis
- Department of Medical Physics and BioengineeringUniversity College LondonLondonUK
| | - Sachio Takashima
- Yanagawa Institute for Developmental DisabilitiesInternational University of Health and WelfareFukuokaJapan
| | - Toyojiro Matsuishi
- Centre for Developmental and Cognitive NeuroscienceDepartment of Paediatrics and Child HealthKurume University School of MedicineKurumeFukuokaJapan
| | | | - Osuke Iwata
- Centre for Developmental and Cognitive NeuroscienceDepartment of Paediatrics and Child HealthKurume University School of MedicineKurumeFukuokaJapan
- Institute for Women's HealthUniversity College LondonLondonUK
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15
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Evaluation of cerebral circulation and oxygen metabolism in infants using near-infrared light. Brain Dev 2014; 36:277-83. [PMID: 23800410 DOI: 10.1016/j.braindev.2013.05.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 05/25/2013] [Accepted: 05/29/2013] [Indexed: 11/22/2022]
Abstract
Bedside monitoring of cerebral circulation or oxygen metabolism in infants to appropriately manage circulation and establish the oxygen dose, aiming at improving the neurological prognosis, is needed in general clinical practice. Near-infrared spectroscopy is used for measurements of neonatal cerebral Hb oxygen saturation, cerebral blood volume, cerebral blood flow and cerebral metabolic rate of oxygen. Near-infrared time-resolved spectroscopy is particularly useful for bedside evaluation of cerebral circulation and oxygen metabolism because of its simple measurement procedure. Combined evaluation of cerebral blood volume and cerebral Hb oxygen saturation is expected to contribute to treatment centering on the brain in neonatal medical care.
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16
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Arora R, Ridha M, Lee DSC, Elliott J, Rosenberg HC, Diop M, Lee TY, St Lawrence K. Preservation of the metabolic rate of oxygen in preterm infants during indomethacin therapy for closure of the ductus arteriosus. Pediatr Res 2013; 73:713-8. [PMID: 23493169 DOI: 10.1038/pr.2013.53] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND The aim of this study was to assess and quantify the effects of indomethacin on cerebral blood flow (CBF), oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO2) in preterm infants undergoing treatment for a patent ductus arteriosus (PDA). METHODS CBF and CMRO2 were measured before and after the first dose of a 3-d course of indomethacin to close hemodynamically significant PDA in preterm neonates. Indocyanine-green (ICG) concentration curves were acquired before and after indomethacin injection to quantify CBF and CMRO2. RESULTS Eight preterm neonates (gestational age, 27.6 ± 0.5 wk; birth weight, 992 ± 109 g; 6 males:2 females) were treated at a median age of 4.5 d (range, 4-21 d). Indomethacin resulted in an average CBF decrease of 18% (pre- and post-CBF = 12.9 ± 1.3 and 10.6 ± 0.8 ml/100 g/min, respectively) and an OEF increase of 11% (pre- and post-OEF = 0.38 ± 0.02 and 0.42 ± 0.02, respectively) but no significant change in CMRO2 (pre- and post-CMRO2 = 0.83 ± 0.07 and 0.76 ± 0.07 ml O2/100 g/min, respectively). Corresponding mean blood pressure (BP), arterial oxygen saturation (SaO2), heart rate, and end-tidal carbon dioxide tension levels remained unchanged. CONCLUSION Indomethacin resulted in significant reduction in CBF but did not alter CMRO2 because of a compensatory increase in OEF.
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Affiliation(s)
- Rohit Arora
- Department of Pediatrics, Western University, London, Ontario, Canada
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17
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Yang R, Zhang Q, Wu Y, Dunn JF. Monitoring angiogenesis using a human compatible calibration for broadband near-infrared spectroscopy. JOURNAL OF BIOMEDICAL OPTICS 2013; 18:16011. [PMID: 23314579 PMCID: PMC3595713 DOI: 10.1117/1.jbo.18.1.016011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Revised: 11/06/2012] [Accepted: 12/06/2012] [Indexed: 05/20/2023]
Abstract
Angiogenesis is a hallmark of many conditions, including cancer, stroke, vascular disease, diabetes, and high-altitude exposure. We have previously shown that one can study angiogenesis in animal models by using total hemoglobin (tHb) as a marker of cerebral blood volume (CBV), measured using broadband near-infrared spectroscopy (bNIRS). However, the method was not suitable for patients as global anoxia was used for the calibration. Here we determine if angiogenesis could be detected using a calibration method that could be applied to patients. CBV, as a marker of angiogenesis, is quantified in a rat cortex before and after hypoxia acclimation. Rats are acclimated at 370-mmHg pressure for three weeks, while rats in the control group are housed under the same conditions, but under normal pressure. CBV increased in each animal in the acclimation group. The mean CBV (%volume/volume) is 3.49%± 0.43% (mean ± SD) before acclimation for the experimental group, and 4.76%± 0.29% after acclimation. The CBV for the control group is 3.28%± 0.75%, and 3.09%± 0.48% for the two measurements. This demonstrates that angiogenesis can be monitored noninvasively over time using a bNIRS system with a calibration method that is compatible with human use and less stressful for studies using animals.
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Affiliation(s)
- Runze Yang
- University of Calgary, Department of Radiology, Calgary, Alberta, Canada
- University of Calgary, Hotchkiss Brain Institute, Calgary, Alberta, Canada
| | - Qiong Zhang
- University of Calgary, Department of Radiology, Calgary, Alberta, Canada
- University of Calgary, Hotchkiss Brain Institute, Calgary, Alberta, Canada
| | - Ying Wu
- University of Calgary, Department of Radiology, Calgary, Alberta, Canada
- University of Calgary, Hotchkiss Brain Institute, Calgary, Alberta, Canada
| | - Jeff F. Dunn
- University of Calgary, Department of Radiology, Calgary, Alberta, Canada
- University of Calgary, Hotchkiss Brain Institute, Calgary, Alberta, Canada
- University of Calgary, Experimental Imaging Centre, Calgary, Alberta, Canada
- Address all correspondence: Jeff F. Dunn, University of Calgary, Department of Radiology, 3330 Hospital Drive, N.W., Calgary, AB T2N 4N1, Canada. Tel: 403-210-3886; E-mail:
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18
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Cooper JA, Tichauer KM, Boulton M, Elliott J, Diop M, Arango M, Lee TY, St Lawrence K. Continuous monitoring of absolute cerebral blood flow by near-infrared spectroscopy during global and focal temporary vessel occlusion. J Appl Physiol (1985) 2011; 110:1691-8. [PMID: 21454747 DOI: 10.1152/japplphysiol.01458.2010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Treatment of intracranial aneurysms by surgical clipping carries a risk of intraoperative ischemia, caused mainly by prolonged temporary occlusion of cerebral arteries. The objective of this study was to develop a near-infrared spectroscopy (NIRS) technique for continuous monitoring of cerebral blood flow (CBF) during surgery. With this approach, cerebral hemodynamics prior to clipping are measured by a bolus-tracking method that uses indocyanine green as an intravascular contrast agent. The baseline hemodynamic measurements are then used to convert the continuous Hb difference (HbD) signal (HbD = oxyhemoglobin - deoxyhemoglobin) acquired during vessel occlusion to units of CBF. To validate the approach, HbD signal changes, along with the corresponding CBF changes, were measured in pigs following occlusion of the common carotid arteries or a middle cerebral artery. For both occlusion models, the predicted CBF change derived from the HbD signal strongly correlated with the measured change in CBF. Linear regression of the predicted and measured CBF changes resulted in a slope of 0.962 (R(2) = 0.909) following carotid occlusion and 0.939 (R(2) = 0.907) following middle cerebral artery occlusion. These results suggest that calibrating the HbD signal by baseline hemodynamic measurements provides a clinically feasible method of monitoring CBF changes during neurosurgery.
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Affiliation(s)
- Joel A Cooper
- Imaging Division, Lawson Health Research Institute, 268 Grosvenor St., London, ON, Canada N6A 4V2
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19
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Diop M, Tichauer KM, Elliott JT, Migueis M, Lee TY, St Lawrence K. Comparison of time-resolved and continuous-wave near-infrared techniques for measuring cerebral blood flow in piglets. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:057004. [PMID: 21054120 DOI: 10.1117/1.3488626] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
A primary focus of neurointensive care is monitoring the injured brain to detect harmful events that can impair cerebral blood flow (CBF), resulting in further injury. Since current noninvasive methods used in the clinic can only assess blood flow indirectly, the goal of this research is to develop an optical technique for measuring absolute CBF. A time-resolved near-infrared (TR-NIR) apparatus is built and CBF is determined by a bolus-tracking method using indocyanine green as an intravascular flow tracer. As a first step in the validation of this technique, CBF is measured in newborn piglets to avoid signal contamination from extracerebral tissue. Measurements are acquired under three conditions: normocapnia, hypercapnia, and following carotid occlusion. For comparison, CBF is concurrently measured by a previously developed continuous-wave NIR method. A strong correlation between CBF measurements from the two techniques is revealed with a slope of 0.79±0.06, an intercept of -2.2±2.5 ml∕100 g∕min, and an R2 of 0.810±0.088. Results demonstrate that TR-NIR can measure CBF with reasonable accuracy and is sensitive to flow changes. The discrepancy between the two methods at higher CBF could be caused by differences in depth sensitivities between continuous-wave and time-resolved measurements.
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Affiliation(s)
- Mamadou Diop
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada N6A 4V2.
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20
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Tichauer KM, Elliott JT, Hadway JA, Lee DS, Lee TY, St. Lawrence K. Using near-infrared spectroscopy to measure cerebral metabolic rate of oxygen under multiple levels of arterial oxygenation in piglets. J Appl Physiol (1985) 2010; 109:878-85. [DOI: 10.1152/japplphysiol.01432.2009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Improving neurological care of neonates has been impeded by the absence of suitable techniques for measuring cerebral hemodynamics and energy metabolism at the bedside. Currently, near-infrared spectroscopy (NIRS) appears to be the technology best suited to fill this gap, and techniques have been proposed to measure both cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2). We have developed a fast and reliable bolus-tracking method of determining CMRO2 that combines measurements of CBF and cerebral venous oxygenation [venous oxygen saturation (CSvO2)]. However, this method has never been validated at different levels of arterial oxygenation [arterial oxygen saturation (SaO2)], which can be highly variable in the clinical setting. In this study, NIRS measurements of CBF, CSvO2, and CMRO2 were obtained over a range of SaO2 in newborn piglets ( n = 12); CSvO2 values measured directly from sagittal sinus blood samples were collected for validation. Two alternative NIRS methods that measure CSvO2 by manipulating venous oxygenation (i.e., head tilt and partial venous occlusion methods) were also employed for comparison. Statistically significant correlations were found between each NIRS technique and sagittal sinus blood oxygenation ( P < 0.05). Correlation slopes were 1.03 ( r = 0.91), 0.73 ( r = 0.73), and 0.73 ( r = 0.81) for the bolus-tracking, head tilt, and partial venous occlusion methods, respectively. The bolus-tracking technique displayed the best correlation under hyperoxic (SaO2 = 99.9 ± 0.03%) and normoxic (SaO2 = 86.9 ± 6.6%) conditions and was comparable to the other techniques under hypoxic conditions (SaO2 = 40.7 ± 9.9%). The reduced precision of the bolus-tracking method under hypoxia was attributed to errors in CSvO2 measurement that were magnified at low SaO2 levels. In conclusion, the bolus-tracking technique of measuring CSvO2, and therefore CMRO2, is accurate and robust for an SaO2 > 50% but provides reduced accuracy under more severe hypoxic levels.
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Affiliation(s)
- Kenneth M. Tichauer
- Imaging Division, Lawson Health Research Institute,
- Department of Medical Biophysics, University of Western Ontario,
| | - Jonathan T. Elliott
- Imaging Division, Lawson Health Research Institute,
- Department of Medical Biophysics, University of Western Ontario,
| | - Jennifer A. Hadway
- Imaging Division, Lawson Health Research Institute,
- Imaging Research Laboratories, Robarts Research Institute, and
| | - David S. Lee
- Department of Paediatrics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Ting-Yim Lee
- Imaging Division, Lawson Health Research Institute,
- Department of Medical Biophysics, University of Western Ontario,
- Imaging Research Laboratories, Robarts Research Institute, and
| | - Keith St. Lawrence
- Imaging Division, Lawson Health Research Institute,
- Department of Medical Biophysics, University of Western Ontario,
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21
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Zhang Q, Srinivasan S, Wu Y, Natah S, Dunn JF. A near-infrared calibration method suitable for quantification of broadband data in humans. J Neurosci Methods 2010; 188:181-6. [PMID: 20156483 DOI: 10.1016/j.jneumeth.2010.01.037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2009] [Revised: 01/25/2010] [Accepted: 01/26/2010] [Indexed: 11/17/2022]
Abstract
Broadband near-infrared spectroscopy (bNIRS) is a powerful non-invasive technique for the measurement of hemoglobin. bNIRS systems are relatively simple to construct compared with many near-infrared instruments since they operate on the principle of continuous wave. The advantage of the broadband method is the capacity to model the spectra and to use "the second differential method" to quantify deoxyhemoglobin (HHb). An "anoxia pulse" method can be applied to quantify total haemoglobin (tHb) and tissue oxygen saturation (S(t)O(2)). A disadvantage is that this calibration method is not suitable for application in humans. In this study, we compared the "anoxia pulse" method with "graded hypoxia" method, which can be applied for human studies, to quantify tHb and S(t)O(2). The values obtained with the two methods were respectively (tHb=47.8+/-2.8 and 49.4+/-7.7 microM, mean+/-S.D., n=8) and (S(t)O(2)=72.8+/-3.7% and 73.2+/-5.7%, mean+/-S.D., n=8). There was no significant difference (p<0.05) between the two methods, indicating that the graded hypoxia method could be used for quantification of tHb and S(t)O(2) in human subjects.
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Affiliation(s)
- Qiong Zhang
- Faculty of Medicine, University of Calgary, Experimental Imaging Centre, Alberta, Canada
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22
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Elliott JT, Diop M, Tichauer KM, Lee TY, St Lawrence K. Quantitative measurement of cerebral blood flow in a juvenile porcine model by depth-resolved near-infrared spectroscopy. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:037014. [PMID: 20615043 DOI: 10.1117/1.3449579] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Nearly half a million children and young adults are affected by traumatic brain injury each year in the United States. Although adequate cerebral blood flow (CBF) is essential to recovery, complications that disrupt blood flow to the brain and exacerbate neurological injury often go undetected because no adequate bedside measure of CBF exists. In this study we validate a depth-resolved, near-infrared spectroscopy (NIRS) technique that provides quantitative CBF measurement despite significant signal contamination from skull and scalp tissue. The respiration rates of eight anesthetized pigs (weight: 16.2+/-0.5 kg, age: 1 to 2 months old) are modulated to achieve a range of CBF levels. Concomitant CBF measurements are performed with NIRS and CT perfusion. A significant correlation between CBF measurements from the two techniques is demonstrated (r(2)=0.714, slope=0.92, p<0.001), and the bias between the two techniques is -2.83 mL min(-1)100 g(-1) (CI(0.95): -19.63 mL min(-1)100 g(-1)-13.9 mL min(-1)100 g(-1)). This study demonstrates that accurate measurements of CBF can be achieved with depth-resolved NIRS despite significant signal contamination from scalp and skull. The ability to measure CBF at the bedside provides a means of detecting, and thereby preventing, secondary ischemia during neurointensive care.
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Affiliation(s)
- Jonathan T Elliott
- University of Western Ontario, Department of Medical Biophysics, London, Ontario N6A 3K7, Canada.
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23
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Tichauer KM, Elliott JT, Hadway JA, Lee TY, St. Lawrence K. Cerebral metabolic rate of oxygen and amplitude-integrated electroencephalography during early reperfusion after hypoxia-ischemia in piglets. J Appl Physiol (1985) 2009; 106:1506-12. [DOI: 10.1152/japplphysiol.91156.2008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The therapeutic window following perinatal hypoxia-ischemia is brief, and early clinical signs of injury can be subtle. Electroencephalography (EEG) represents the most promising early diagnostic of hypoxia-ischemia; however, some studies have questioned the sensitivity and specificity of EEG. The present study investigated the use of both near-infrared spectroscopy (NIRS) measurements of the cerebral metabolic rate of oxygen (CMRO2) and amplitude-integrated EEG (aEEG) to detect the severity of hypoxia-ischemia after 1 h of reperfusion in newborn piglets (10 insult, 3 control). The CMRO2 was measured before and after 1 h of reperfusion from hypoxia-ischemia, the duration of which was varied from piglet to piglet with a range of 3–24 min, under fentanyl/nitrous oxide anesthesia to mimic awake-like levels of cerebral metabolism. EEG data were collected throughout the study. On average, the CMRO2 and mean aEEG background signals were significantly depressed following the insult ( P < 0.05). Mean CMRO2 and mean aEEG background were 2.61 ± 0.11 ml O2·min−1·100 g−1 and 20.4 ± 2.7 μV before the insult and 1.58 ± 0.09 ml O2·min−1·100 g−1 and 11.8 ± 2.9 μV after 1 h of reperfusion, respectively. Both CMRO2 and aEEG displayed statistically significant correlations with duration of ischemia ( P < 0.05; r = 0.71 and r = 0.89, respectively); however, only CMRO2 was sensitive to milder injuries (<5 min). This study highlights the potential for combining NIRS measures of CMRO2 with EEG in the neonatal intensive care unit to improve early detection of perinatal hypoxia-ischemia.
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24
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Diop M, Elliott JT, Tichauer KM, Lee TY, St Lawrence K. A broadband continuous-wave multichannel near-infrared system for measuring regional cerebral blood flow and oxygen consumption in newborn piglets. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2009; 80:054302. [PMID: 19485521 DOI: 10.1063/1.3123347] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Near-infrared spectroscopy (NIRS) is a promising technique for assessing brain function in newborns, particularly due to its portability and sensitivity to cerebral hemodynamics and oxygenation. Methods for measuring cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO(2)) have been developed based on broadband continuous-wave NIRS. However, broadband NIRS apparatus typically have only one detection channel, which limits their applicability to measuring regional CBF and CMRO(2). In this study, a relatively simple multiplexing approach based on electronically controlled mechanical shutters is proposed to expand the detection capabilities from one to eight channels. The tradeoff is an increase in the sampling interval; however, this has negligible effects on CBF measurements for intervals less than or equal to 1 s. The ability of the system to detect focal brain injury was demonstrated in piglets by injecting endothelin-1 (ET-1) into the cerebral cortex. For validation, CBF was independently measured by computed tomography (CT) perfusion. The average reduction in CBF from the source-detector pair that interrogated the injured region was 51%+/-9%, which was in good agreement with the CBF reduction measured by CT perfusion (55%+/-5%). No significant changes in regional CMRO(2) were observed. The average regional differential pathlength prior to ET-1 injection was 8.4+/-0.2 cm (range of 7.1-9.6 cm) and did not significantly change after the injury.
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Affiliation(s)
- Mamadou Diop
- Imaging Division, Lawson Health Research Institute, London, Ontario N6A 4V2, Canada.
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25
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Tichauer KM, Wong DYL, Hadway JA, Rylett RJ, Lee TY, St Lawrence K. Assessing the severity of perinatal hypoxia-ischemia in piglets using near-infrared spectroscopy to measure the cerebral metabolic rate of oxygen. Pediatr Res 2009; 65:301-6. [PMID: 19033882 DOI: 10.1203/pdr.0b013e318194faa6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Reduced cerebral function after neonatal hypoxia-ischemia is an early indicator of hypoxic-ischemic encephalopathy. Near-infrared spectroscopy offers a clinically relevant means of detecting impaired cerebral metabolism from the measurement of the cerebral metabolic rate of oxygen (CMRO2). The purpose of this study was to determine the relationship between postinsult CMRO2 and duration of hypoxia-ischemia in piglets. Twelve piglets were subjected to randomly selected durations of hypoxia-ischemia (5-28 min) and five animals served as controls. Measurements of CMRO2 were taken before and for 24 h after hypoxia-ischemia. Histology was carried out in nine piglets (six insults, three controls) to estimate brain injury. In the first 4 h after the insult, average CMRO2 of the insult group was significantly depressed (33 +/- 3% reduction compared with controls) and by 8 h, a significant correlation developed, which persisted for the remainder of the study, between CMRO2 and the duration of ischemia. Histologic staining suggested little brain damage resulted from shorter insult durations and considerable damage from more prolonged insults. This study demonstrated that near-infrared spectroscopy could detect early changes in CMRO2 after hypoxia-ischemia for a range of insult severities and CMRO2 could be used to distinguish insult severity by 8 h after the insult.
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Affiliation(s)
- Kenneth M Tichauer
- Imaging Division, Lawson Health Research Institute, London, Ontario, Canada.
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Koziak AM, Winter J, Lee TY, Thompson RT, St. Lawrence KS. Validation study of a pulsed arterial spin labeling technique by comparison to perfusion computed tomography. Magn Reson Imaging 2008; 26:543-53. [DOI: 10.1016/j.mri.2007.10.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Revised: 08/15/2007] [Accepted: 10/08/2007] [Indexed: 10/22/2022]
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Tichauer KM, Brown DW, Hadway J, Lee TY, St Lawrence K. Near-infrared spectroscopy measurements of cerebral blood flow and oxygen consumption following hypoxia-ischemia in newborn piglets. J Appl Physiol (1985) 2006; 100:850-7. [PMID: 16293704 DOI: 10.1152/japplphysiol.00830.2005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Impaired oxidative metabolism following hypoxia-ischemia (HI) is believed to be an early indicator of delayed brain injury. The cerebral metabolic rate of oxygen (CMRO2) can be measured by combining near-infrared spectroscopy (NIRS) measurements of cerebral blood flow (CBF) and cerebral deoxy-hemoglobin concentration. The ability of NIRS to measure changes in CMRO2 following HI was investigated in newborn piglets. Nine piglets were subjected to 30 min of HI by occluding both carotid arteries and reducing the fraction of inspired oxygen to 8%. An additional nine piglets served as sham-operated controls. Measurements of CBF, oxygen extraction fraction (OEF), and CMRO2 were obtained at baseline and at 6 h after the HI insult. Of the three parameters, only CMRO2 showed a persistent and significant change after HI. Five minutes after reoxygenation, there was a 28 ± 12% (mean ± SE) decrease in CMRO2, a 72 ± 50% increase in CBF, and a 56 ± 19% decrease in OEF compared with baseline ( P < 0.05). By 30 min postinsult and for the remainder of the study, there were no significant differences in CBF and OEF between control and insult groups, whereas CMRO2 remained depressed throughout the 6-h postinsult period. This study demonstrates that NIRS can measure decreases in CMRO2 caused by HI. The results highlight the potential for NIRS to be used in the neonatal intensive care unit to detect delayed brain damage.
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Affiliation(s)
- Kenneth M Tichauer
- Imaging Division, Lawson Health Research Institute, 268 Grosvenor St., London, Ontario, Canada N6A 4V2
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