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Vasireddi A, Schaefer PW, Rohatgi S. Metabolic Imaging of Acute Ischemic Stroke (PET, 1Hydrogen Spectroscopy, 17Oxygen Imaging, 23Sodium MRI, pH Imaging). Neuroimaging Clin N Am 2024; 34:271-280. [PMID: 38604711 DOI: 10.1016/j.nic.2024.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2024]
Abstract
Acute stroke imaging plays a vital and time-sensitive role in therapeutic decision-making. Current clinical workflows widely use computed tomography (CT) and magnetic resonance (MR) techniques including CT and MR perfusion to estimate the volume of ischemic penumbra at risk for infarction without acute intervention. The use of imaging techniques aimed toward evaluating the metabolic derangements underlying a developing infarct may provide additional information for differentiating the penumbra from benign oligemia and infarct core. The authors review several modalities of metabolic imaging including PET, hydrogen and oxygen spectroscopy, sodium MRI, and pH-weighted MRI.
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Affiliation(s)
- Anil Vasireddi
- Division of Neuroradiology, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA.
| | - Pamela W Schaefer
- Division of Neuroradiology, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA
| | - Saurabh Rohatgi
- Division of Neuroradiology, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA
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Bøgh N, Sørensen CB, Alstrup AKO, Hansen ESS, Andersen OM, Laustsen C. Mice and minipigs with compromised expression of the Alzheimer's disease gene SORL1 show cerebral metabolic disturbances on hyperpolarized [1- 13C]pyruvate and sodium MRI. Brain Commun 2024; 6:fcae114. [PMID: 38650831 PMCID: PMC11034025 DOI: 10.1093/braincomms/fcae114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/24/2024] [Accepted: 03/29/2024] [Indexed: 04/25/2024] Open
Abstract
The sortilin-related receptor 1 (SORL1) gene, encoding the cellular endosomal sorting-related receptor with A-type repeats (SORLA), is now established as a causal gene for Alzheimer's disease. As the latest addition to the list of causal genes, the pathophysiological effects and biomarker potential of SORL1 variants remain relatively undiscovered. Metabolic dysfunction is, however, well described in patients with Alzheimer's disease and is used as an imaging biomarker in clinical diagnosis settings. To understand the metabolic consequences of loss-of-function SORL1 mutations, we applied two metabolic MRI technologies, sodium (23Na) MRI and MRI with hyperpolarized [1-13C]pyruvate, in minipigs and mice with compromised expression of SORL1. At the age analysed here, both animal models display no conventional imaging evidence of neurodegeneration but show biochemical signs of elevated amyloid production, thus representing the early preclinical disease. With hyperpolarized MRI, the exchange from [1-13C]pyruvate to [1-13C]lactate and 13C-bicarbonate was decreased by 32 and 23%, respectively, in the cerebrum of SORL1-haploinsufficient minipigs. A robust 11% decrease in the sodium content was observed with 23Na-MRI in the same minipigs. Comparably, the brain sodium concentration gradually decreased from control to SORL1 haploinsufficient (-11%) to SORL1 knockout mice (-23%), suggesting a gene dose dependence in the metabolic dysfunction. The present study highlights that metabolic MRI technologies are sensitive to the functional, metabolic consequences of Alzheimer's disease and Alzheimer's disease-linked genotypes. Further, the study suggests a potential avenue of research into the mechanisms of metabolic alterations by SORL1 mutations and their potential role in neurodegeneration.
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Affiliation(s)
- Nikolaj Bøgh
- Department of Clinical Medicine, The MR Research Centre, Aarhus University, 8200 Aarhus, Denmark
- A&E, Gødstrup Hospital, 7400 Herning, Denmark
| | | | - Aage K O Alstrup
- Department of Clinical Medicine, Aarhus University, 8200 Aarhus, Denmark
- Department of Nuclear Medicine and PET-Centre, Aarhus University Hospital, 8200 Aarhus, Denmark
| | - Esben S S Hansen
- Department of Clinical Medicine, The MR Research Centre, Aarhus University, 8200 Aarhus, Denmark
| | - Olav M Andersen
- Department of Biomedicine, Aarhus University, 8200 Aarhus, Denmark
| | - Christoffer Laustsen
- Department of Clinical Medicine, The MR Research Centre, Aarhus University, 8200 Aarhus, Denmark
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Helsper S, Yuan X, Bagdasarian FA, Athey J, Li Y, Borlongan CV, Grant SC. Multinuclear MRI Reveals Early Efficacy of Stem Cell Therapy in Stroke. Transl Stroke Res 2023; 14:545-561. [PMID: 35900719 PMCID: PMC10733402 DOI: 10.1007/s12975-022-01057-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 04/28/2022] [Accepted: 06/16/2022] [Indexed: 10/16/2022]
Abstract
Compromised adult human mesenchymal stem cells (hMSC) can impair cell therapy efficacy and further reverse ischemic recovery. However, in vitro assays require extended passage to characterize cells, limiting rapid assessment for therapeutic potency. Multinuclear magnetic resonance imaging and spectroscopy (MRI/S) provides near real-time feedback on disease progression and tissue recovery. Applied to ischemic stroke, 23Na MRI evaluates treatment efficacy within 24 h after middle cerebral artery occlusion, showing recovery of sodium homeostasis and lesion reduction in specimens treated with hMSC while 1H MRS identifies reduction in lactate levels. This combined metric was confirmed by evaluating treatment groups receiving healthy or compromised hMSC versus vehicle (sham saline injection) over 21 days. Behavioral tests to assess functional recovery and cell analysis for immunomodulatory and macrophage activity to detect hMSC potency confirm MR findings. Clinically, these MR metrics may prove critical to early evaluations of therapeutic efficacy and overall stroke recovery.
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Affiliation(s)
- Shannon Helsper
- The National High Magnetic Field Laboratory, Florida State University, 1800 E. Paul Dirac Dr, Tallahassee, FL, 32310, USA
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, FL, 32310, USA
| | - Xuegang Yuan
- The National High Magnetic Field Laboratory, Florida State University, 1800 E. Paul Dirac Dr, Tallahassee, FL, 32310, USA
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, FL, 32310, USA
| | - F Andrew Bagdasarian
- The National High Magnetic Field Laboratory, Florida State University, 1800 E. Paul Dirac Dr, Tallahassee, FL, 32310, USA
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, FL, 32310, USA
| | - Jacob Athey
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, FL, 32310, USA
| | - Yan Li
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, FL, 32310, USA
| | - Cesario V Borlongan
- Center of Excellence for Aging & Brain Repair, University of South Florida, Tampa, FL, 33612, USA
| | - Samuel C Grant
- The National High Magnetic Field Laboratory, Florida State University, 1800 E. Paul Dirac Dr, Tallahassee, FL, 32310, USA.
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, FL, 32310, USA.
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Adlung A, Licht C, Reichert S, Özdemir S, Mohamed SA, Samartzi M, Fatar M, Gass A, Prost EN, Schad LR. Quantification of tissue sodium concentration in the ischemic stroke: A comparison between external and internal references for 23Na MRI. J Neurosci Methods 2022; 382:109721. [PMID: 36202191 DOI: 10.1016/j.jneumeth.2022.109721] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 09/28/2022] [Accepted: 09/30/2022] [Indexed: 11/06/2022]
Affiliation(s)
- Anne Adlung
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Germany.
| | - Christian Licht
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Germany
| | - Simon Reichert
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Germany
| | - Safa Özdemir
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Germany
| | - Sherif A Mohamed
- Department of Neuroradiology, Medical Faculty Mannheim, Heidelberg University, Germany; Clinic for Diagnostic and Interventional Radiology, University Hospital Heidelberg, Germany
| | - Melina Samartzi
- Department of Neurology, Medical Faculty Mannheim and Mannheim Center of Translational Neurosciences (MCTN), Heidelberg University, Germany
| | - Marc Fatar
- Department of Neurology, Medical Faculty Mannheim and Mannheim Center of Translational Neurosciences (MCTN), Heidelberg University, Germany
| | - Achim Gass
- Department of Neurology, Medical Faculty Mannheim and Mannheim Center of Translational Neurosciences (MCTN), Heidelberg University, Germany
| | - Eva Neumaier Prost
- Department of Neuroradiology, Medical Faculty Mannheim, Heidelberg University, Germany
| | - Lothar R Schad
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Germany
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Bhatia A, Lee VK, Qian Y, Paldino MJ, Ceschin R, Hect J, Mountz JM, Sun D, Kohanbash G, Pollack IF, Jakacki RI, Boada F, Panigrahy A. Quantitative Sodium ( 23Na) MRI in Pediatric Gliomas: Initial Experience. Diagnostics (Basel) 2022; 12:diagnostics12051223. [PMID: 35626378 PMCID: PMC9140048 DOI: 10.3390/diagnostics12051223] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 04/29/2022] [Accepted: 05/05/2022] [Indexed: 02/05/2023] Open
Abstract
Background: 23Na MRI correlates with tumor proliferation, and studies in pediatric patients are lacking. The purpose of the study: (1) to compare total sodium concentration (TSC) between pediatric glioma and non-neoplastic brain tissue using 23Na MRI; (2) compare tissue conspicuity of bound sodium concentration (BSC) using 23Na MRI dual echo relative to TSC imaging. Methods: TSC was measured in: (1) non-neoplastic brain tissues and (2) three types of manually segmented gliomas (diffuse intrinsic brainstem glioma (DIPG), recurrent supratentorial low-grade glioma (LGG), and high-grade glioma (HGG)). In a subset of patients, serial changes in both TSC and BSC (dual echo 23Na MRI) were assessed. Results: Twenty-six pediatric patients with gliomas (median age of 12.0 years, range 4.9−23.3 years) were scanned with 23Na MRI. DIPG treated with RT demonstrated higher TSC values than the uninvolved infratentorial tissues (p < 0.001). Recurrent supratentorial LGG and HGG exhibited higher TSC values than the uninvolved white matter (WM) and gray matter (GM) (p < 0.002 for LGG, and p < 0.02 for HGG). The dual echo 23Na MRI suppressed the sodium signal within both CSF and necrotic foci. Conclusion: Quantitative 23Na MRI of pediatric gliomas demonstrates a range of values that are higher than non-neoplastic tissues. Dual echo 23Na MRI of BCS improves tissue conspicuity relative to TSC imaging.
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Affiliation(s)
- Aashim Bhatia
- Department of Radiology, Children’s Hospital of Philadelphia, 3401 Civic Center Blvd., Philadelphia, PA 19096, USA
- Correspondence: ; Tel.: +1-267-317-6688
| | - Vincent Kyu Lee
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA 15260, USA; (V.K.L.); (M.J.P.); (R.C.); (J.H.); (J.M.M.); (A.P.)
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Yongxian Qian
- Center for Biomedical Imaging, Department of Radiology, University of Pittsburgh, Pittsburgh, PA 15260, USA; (Y.Q.); (R.I.J.)
| | - Michael J. Paldino
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA 15260, USA; (V.K.L.); (M.J.P.); (R.C.); (J.H.); (J.M.M.); (A.P.)
| | - Rafael Ceschin
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA 15260, USA; (V.K.L.); (M.J.P.); (R.C.); (J.H.); (J.M.M.); (A.P.)
| | - Jasmine Hect
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA 15260, USA; (V.K.L.); (M.J.P.); (R.C.); (J.H.); (J.M.M.); (A.P.)
| | - James M. Mountz
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA 15260, USA; (V.K.L.); (M.J.P.); (R.C.); (J.H.); (J.M.M.); (A.P.)
| | - Dandan Sun
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15260, USA;
- Geriatric Research, Educational and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA 15240, USA
| | - Gary Kohanbash
- Neurological Surgery, University of Pittsburgh, Pittsburgh, PA 15260, USA; (G.K.); (I.F.P.)
| | - Ian F. Pollack
- Neurological Surgery, University of Pittsburgh, Pittsburgh, PA 15260, USA; (G.K.); (I.F.P.)
| | - Regina I. Jakacki
- Center for Biomedical Imaging, Department of Radiology, University of Pittsburgh, Pittsburgh, PA 15260, USA; (Y.Q.); (R.I.J.)
| | - Fernando Boada
- New York University Grossman School of Medicine, New York, NY 10016, USA;
| | - Ashok Panigrahy
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA 15260, USA; (V.K.L.); (M.J.P.); (R.C.); (J.H.); (J.M.M.); (A.P.)
- UPMC Hillman Cancer Center, Pittsburgh, PA 15232, USA
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Exposure to 16 h of normobaric hypoxia induces ionic edema in the healthy brain. Nat Commun 2021; 12:5987. [PMID: 34645793 PMCID: PMC8514510 DOI: 10.1038/s41467-021-26116-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 09/09/2021] [Indexed: 11/10/2022] Open
Abstract
Following prolonged exposure to hypoxic conditions, for example, due to ascent to high altitude, stroke, or traumatic brain injury, cerebral edema can develop. The exact nature and genesis of hypoxia-induced edema in healthy individuals remain unresolved. We examined the effects of prolonged, normobaric hypoxia, induced by 16 h of exposure to simulated high altitude, on healthy brains using proton, dynamic contrast enhanced, and sodium MRI. This dual approach allowed us to directly measure key factors in the development of hypoxia-induced brain edema: (1) Sodium signals as a surrogate of the distribution of electrolytes within the cerebral tissue and (2) Ktrans as a marker of blood–brain–barrier integrity. The measurements point toward an accumulation of sodium ions in extra- but not in intracellular space in combination with an intact endothelium. Both findings in combination are indicative of ionic extracellular edema, a subtype of cerebral edema that was only recently specified as an intermittent, yet distinct stage between cytotoxic and vasogenic edemas. In sum, here a combination of imaging techniques demonstrates the development of ionic edemas following prolonged normobaric hypoxia in agreement with cascadic models of edema formation. Prolonged hypoxia, which can be due to stroke or ascent to high altitude, can lead to cerebral edema. Here, the authors used a combination of sodium and proton MRI and experimentally induced hypoxic conditions to identify the cause for brain swelling: Ionic edema, an intermediate between cytotoxic and vasogenic edema defined by sodium ion accumulation in extracellular space and an intact endothelium.
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Lu J, Mei Q, Hou X, Manaenko A, Zhou L, Liebeskind DS, Zhang JH, Li Y, Hu Q. Imaging Acute Stroke: From One-Size-Fit-All to Biomarkers. Front Neurol 2021; 12:697779. [PMID: 34630278 PMCID: PMC8497192 DOI: 10.3389/fneur.2021.697779] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 06/30/2021] [Indexed: 12/27/2022] Open
Abstract
In acute stroke management, time window has been rigidly used as a guide for decades and the reperfusion treatment is only available in the first few limited hours. Recently, imaging-based selection of patients has successfully expanded the treatment window out to 16 and even 24 h in the DEFUSE 3 and DAWN trials, respectively. Recent guidelines recommend the use of imaging techniques to guide therapeutic decision-making and expanded eligibility in acute ischemic stroke. A tissue window is proposed to replace the time window and serve as the surrogate marker for potentially salvageable tissue. This article reviews the evolution of time window, addresses the advantage of a tissue window in precision medicine for ischemic stroke, and discusses both the established and emerging techniques of neuroimaging and their roles in defining a tissue window. We also emphasize the metabolic imaging and molecular imaging of brain pathophysiology, and highlight its potential in patient selection and treatment response prediction in ischemic stroke.
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Affiliation(s)
- Jianfei Lu
- Central Laboratory, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qiyong Mei
- Department of Neurosurgery, Changzheng Hospital, Navy Medical University, Shanghai, China
| | - Xianhua Hou
- Department of Neurology, Southwest Hospital, Army Medical University, Chongqing, China
| | - Anatol Manaenko
- National Health Commission Key Laboratory of Diagnosis and Treatment on Brain Functional Diseases, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Lili Zhou
- Department of Neurology, Chinese People's Liberation Army General Hospital, Beijing, China
| | - David S. Liebeskind
- Neurovascular Imaging Research Core and University of California Los Angeles Stroke Center, University of California, Los Angeles, Los Angeles, CA, United States
| | - John H. Zhang
- Department of Anesthesiology, Loma Linda University School of Medicine, Loma Linda, CA, United States
| | - Yao Li
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Qin Hu
- Central Laboratory, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Obenaus A, Badaut J. Role of the noninvasive imaging techniques in monitoring and understanding the evolution of brain edema. J Neurosci Res 2021; 100:1191-1200. [PMID: 34048088 DOI: 10.1002/jnr.24837] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 03/13/2021] [Indexed: 12/21/2022]
Abstract
Human brain injury elicits accumulation of water within the brain due to a variety of pathophysiological processes. As our understanding of edema emerged two temporally (and cellular) distinct processes were identified, cytotoxic and vasogenic edema. The emergence of both types of edema is reflected by the temporal evolution and is influenced by the underlying pathology (type and extent). However, this two-edema compartment model does not adequately describe the transition between cytotoxic and vasogenic edema. Hence, a third category has been proposed, termed ionic edema, that is observed in the transition between cytotoxic and vasogenic edema. Magnetic resonance neuroimaging of edema today primarily utilizes T2-weighted (T2WI) and diffusion-weighted imaging (DWI). Clinical diagnostics and translational science studies have clearly demonstrated the temporal ability of both T2WI and DWI to monitor edema content and evolution. DWI measures water mobility within the brain reflecting cytotoxic edema. T2WI at later time points when vasogenic edema develops visualizes increased water content in the brain. Clinically relevant imaging modalities, including ultrasound and positron emission tomography, are not typically used to assess edema. In sum, edema imaging is an important cornerstone of clinical diagnostics and translational studies and can guide effective therapeutics manage edema and improve patient outcomes.
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Affiliation(s)
- Andre Obenaus
- Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, USA.,Department of Pediatrics, University of California, Irvine, Irvine, CA, USA
| | - Jérôme Badaut
- Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, USA.,CNRS UMR5287, INCIA, University of Bordeaux, Bordeaux, France
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Modo M. 19F Magnetic Resonance Imaging and Spectroscopy in Neuroscience. Neuroscience 2021; 474:37-50. [PMID: 33766776 DOI: 10.1016/j.neuroscience.2021.03.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 03/11/2021] [Accepted: 03/12/2021] [Indexed: 12/23/2022]
Abstract
1H magnetic resonance imaging (MRI) has established itself as a key diagnostic technique, affording the visualization of brain anatomy, blood flow, activity and connectivity. The detection of other atoms (e.g. 19F, 23Na, 31P), so called hetero-nuclear MRI and spectroscopy (MRS), provides investigative avenues that complement and extend the richness of information that can be gained from 1H MRI. Especially 19F MRI is increasingly emerging as a multi-nuclear (1H/19F) technique that can be exploited to visualize cell migration and trafficking. The lack of a 19F background signal in the brain affords an unequivocal detection suitable for quantification. Fluorine-based contrast material can be engineered as nanoemulsions, nanocapsules, or nanoparticles to label cells in vitro or in vivo. Fluorinated blood substitutes, typically nanoemulsions, can also carry oxygen and serve as a theranostic in poorly perfused brain regions. Brain tissue concentrations of fluorinated pharmaceuticals, including inhalation anesthetics (e.g. isoflurane) and anti-depressants (e.g. fluoxetine), can also be measured using MRS. However, the low signal from these compounds provides a challenge for imaging. Further methodological advances that accelerate signal acquisition (e.g. compressed sensing, cryogenic coils) are required to expand the applications of 19F MR imaging to, for instance, determine the regional pharmacokinetics of novel fluorine-based drugs. Improvements in 19F signal detection and localization, combined with the development of novel sensitive probes, will increase the utility of these multi-nuclear studies. These advances will provide new insights into cellular and molecular processes involved in neurodegenerative disease, as well as the mode of action of pharmaceutical compounds.
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Affiliation(s)
- Michel Modo
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA.
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Adlung A, Samartzi M, Schad LR, Neumaier-Probst E, Fatar M, A Mohamed S. Tissue Sodium Concentration within White Matter Correlates with the Extent of Small Vessel Disease. Cerebrovasc Dis 2021; 50:347-355. [PMID: 33730735 DOI: 10.1159/000514133] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 12/22/2020] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION Sodium MRI (23Na MRI) derived biomarkers such as tissue sodium concentration (TSC) provide valuable information on cell function and brain tissue viability and has become a reliable tool for the assessment of brain tumors and ischemic stroke beyond pathoanatomical morphology. Patients with major stroke often suffer from different degrees of underlying white matter lesions (WMLs) attributed to chronic small vessel disease. This study aimed to evaluate the WM TSC in patients with an acute ischemic stroke and to correlate the TSC with the extent of small vessel disease. Furthermore, the reliability of relative TSC (rTSC) compared to absolute TSC in these patients was analyzed. METHODOLOGY We prospectively examined 62 patients with acute ischemic stroke (73 ± 13 years) between November 2016 and August 2019 from which 18 patients were excluded and thus 44 patients were evaluated. A 3D 23Na MRI was acquired in addition to a T2-TIRM and a diffusion-weighted image. Coregistration and segmentation were performed with SPM 12 based on the T2-TIRM image. The extension of WM T2 hyperintense lesions in each patient was classified using the Fazekas scale of WMLs. The absolute TSC in the WM region was correlated to the Fazekas grades. The stroke region was manually segmented on the coregistered absolute diffusion coefficient image and absolute, and rTSC was calculated in the stroke region and compared to nonischemic WM region. Statistical significance was evaluated using the Student t-test. RESULTS For patients with Fazekas grade I (n = 25, age: 68.5 ± 15.1 years), mean TSC in WM was 55.57 ± 7.43 mM, and it was not statistically significant different from patients with Fazekas grade II (n = 7, age: 77.9 ± 6.4 years) with a mean TSC in WM of 53.9 ± 6.4 mM, p = 0.58. For patients with Fazekas grade III (n = 9, age: 81.4 ± 7.9 years), mean TSC in WM was 68.7 ± 10.5 mM, which is statistically significantly higher than the TSC in patients with Fazekas grade I and II (p < 0.001 and p = 0.05, respectively). There was a positive correlation between the TSC in WM and the Fazekas grade with r = 0.48 p < 0.001. The rTSC in the stroke region was statistically significant difference between low (0 and I) and high (2 and 3) Fazekas grades (p = 0.0353) whereas there was no statistically significant difference in absolute TSC in the stroke region between low (0 and I) and high (2 and 3) Fazekas grades. CONCLUSION The significant difference in absolute TSC in WM in patients with severe small vessel disease; Fazekas grade 3 can lead to inaccuracies using rTSC quantification for evaluation of acute ischemic stroke using 23 Na MRI. The study, therefore, emphasizes the importance of absolute tissue sodium quantification.
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Affiliation(s)
- Anne Adlung
- Department of Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Melina Samartzi
- Department of Neurology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Lothar R Schad
- Department of Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Eva Neumaier-Probst
- Department of Neuroradiology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Marc Fatar
- Department of Neurology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Sherif A Mohamed
- Department of Neuroradiology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany,
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Leftin A, Rosenberg JT, Yuan X, Ma T, Grant SC, Frydman L. Multiparametric classification of sub-acute ischemic stroke recovery with ultrafast diffusion, 23 Na, and MPIO-labeled stem cell MRI at 21.1 T. NMR IN BIOMEDICINE 2020; 33:e4186. [PMID: 31797472 PMCID: PMC8170591 DOI: 10.1002/nbm.4186] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 07/11/2019] [Accepted: 07/22/2019] [Indexed: 05/05/2023]
Abstract
MRI leverages multiple modes of contrast to characterize stroke. High-magnetic-field systems enhance the performance of these MRI measurements. Previously, we have demonstrated that individually sodium and stem cell tracking metrics are enhanced at ultrahigh field in a rat model of stroke, and we have developed robust single-scan diffusion-weighted imaging approaches that utilize spatiotemporal encoding (SPEN) of the apparent diffusion coefficient (ADC) for these challenging field strengths. Here, we performed a multiparametric study of middle cerebral artery occlusion (MCAO) biomarker evolution focusing on comparison of these MRI biomarkers for stroke assessment during sub-acute recovery in rat MCAO models at 21.1 T. T2 -weighted MRI was used as the benchmark for identification of the ischemic lesion over the course of the study. The number of MPIO-induced voids measured by gradient-recalled echo, the SPEN measurement of ADC, and 23 Na MRI values were determined in the ischemic area and contralateral hemisphere, and relative performances for stroke classification were compared by receiver operator characteristic analysis. These measurements were associated with unique time-dependent trajectories during stroke recovery that changed the sensitivity and specificity for stroke monitoring during its evolution. Advantages and limitations of these contrasts, and the use of ultrahigh field for multiparametric stroke assessment, are discussed.
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Affiliation(s)
- Avigdor Leftin
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
- Department of Radiology, Stony Brook Medicine, Stony Brook University, Stony Brook, NY, USA
| | - Jens T Rosenberg
- The National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA
| | - Xuegang Yuan
- FAMU-FSU Chemical and Biochemical Engineering, Florida State University, Tallahassee, FL, USA
| | - Teng Ma
- FAMU-FSU Chemical and Biochemical Engineering, Florida State University, Tallahassee, FL, USA
| | - Samuel C Grant
- The National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA
- FAMU-FSU Chemical and Biochemical Engineering, Florida State University, Tallahassee, FL, USA
| | - Lucio Frydman
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
- FAMU-FSU Chemical and Biochemical Engineering, Florida State University, Tallahassee, FL, USA
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Coste A, Boumezbeur F, Vignaud A, Madelin G, Reetz K, Le Bihan D, Rabrait-Lerman C, Romanzetti S. Tissue sodium concentration and sodium T 1 mapping of the human brain at 3 T using a Variable Flip Angle method. Magn Reson Imaging 2019; 58:116-124. [PMID: 30695720 DOI: 10.1016/j.mri.2019.01.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 12/28/2018] [Accepted: 01/15/2019] [Indexed: 01/18/2023]
Abstract
PURPOSE The state-of-the-art method to quantify sodium concentrations in vivo consists in a fully relaxed 3D spin-density (SD) weighted acquisition. Nevertheless, most sodium MRI clinical studies use short-TR SD acquisitions to reduce acquisition durations. We present a clinically viable implementation of the Variable Flip Angle (VFA) method for robust and clinically viable quantification of total sodium concentration (TSC) and longitudinal relaxation rates in vivo in human brain at 3 T. METHODS Two non-Cartesian steady-state spoiled ultrashort echo time (UTE) scans, performed at optimized flip angles, repetition time and pulse length determined under specific absorption rate constraints, are used to simultaneously compute T1 and total sodium concentration (TSC) maps using the VFA method. Images are reconstructed using the non-uniform Fast Fourier Transform algorithm and TSC maps are corrected for possible inhomogeneity of coil transmission and reception profiles. Fractioned acquisitions are used to correct for potential patient motion. TSC quantifications obtained using the VFA method are validated at first in comparison with a fully-relaxed SD acquisition in a calibration phantom. The robustness of similar VFA acquisitions are compared to the short-TR SD approach in vivo on seven healthy volunteers. RESULTS The VFA method resulted in consistent TSC and T1 estimates across our cohort of healthy subjects, with mean TSC of 38.1 ± 5.0 mmol/L and T1 of 39.2 ± 4.4 ms. These results are in agreement with previously reported values in literature TSC estimations and with the predictions of a 2-compartment model. However, the short-TR SD acquisition systematically underestimated the sodium concentration with a mean TSC of 31 ± 4.5 mmol/L. CONCLUSION The VFA method can be applied successfully to image sodium at 3 T in about 20 min and provides robust and intrinsically T1-corrected TSC maps.
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Affiliation(s)
- Arthur Coste
- NeuroSpin, CEA DRF-ISVFJ, Paris-Saclay University, Gif-sur-Yvette, France
| | - Fawzi Boumezbeur
- NeuroSpin, CEA DRF-ISVFJ, Paris-Saclay University, Gif-sur-Yvette, France
| | - Alexandre Vignaud
- NeuroSpin, CEA DRF-ISVFJ, Paris-Saclay University, Gif-sur-Yvette, France
| | - Guillaume Madelin
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, USA
| | - Kathrin Reetz
- Department of Neurology, RWTH Aachen University, Aachen, Germany; JARA-BRAIN Institute of Molecular Neuroscience and Neuroimaging, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany
| | - Denis Le Bihan
- NeuroSpin, CEA DRF-ISVFJ, Paris-Saclay University, Gif-sur-Yvette, France
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Martínez-Valverde T, Sánchez-Guerrero A, Vidal-Jorge M, Torné R, Castro L, Gandara D, Munar F, Poca MA, Sahuquillo J. Characterization of the Ionic Profile of the Extracellular Space of the Injured and Ischemic Brain: A Microdialysis Study. J Neurotrauma 2017; 34:74-85. [DOI: 10.1089/neu.2015.4334] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Affiliation(s)
- Tamara Martínez-Valverde
- Neurotraumatology and Neurosurgery Research Unit (UNINN), Vall d'Hebron University Hospital, Universidad Autònoma de Barcelona, Barcelona, Spain
| | - Angela Sánchez-Guerrero
- Neurotraumatology and Neurosurgery Research Unit (UNINN), Vall d'Hebron University Hospital, Universidad Autònoma de Barcelona, Barcelona, Spain
| | - Marian Vidal-Jorge
- Neurotraumatology and Neurosurgery Research Unit (UNINN), Vall d'Hebron University Hospital, Universidad Autònoma de Barcelona, Barcelona, Spain
| | - Ramon Torné
- Neurotraumatology and Neurosurgery Research Unit (UNINN), Vall d'Hebron University Hospital, Universidad Autònoma de Barcelona, Barcelona, Spain
- Department of Neurosurgery, Vall d'Hebron University Hospital, Universidad Autònoma de Barcelona, Barcelona, Spain
| | - Lidia Castro
- Neurotraumatology and Neurosurgery Research Unit (UNINN), Vall d'Hebron University Hospital, Universidad Autònoma de Barcelona, Barcelona, Spain
| | - Dario Gandara
- Department of Neurosurgery, Vall d'Hebron University Hospital, Universidad Autònoma de Barcelona, Barcelona, Spain
| | - Francisca Munar
- Department of Anesthesiology, Vall d'Hebron University Hospital, Universidad Autònoma de Barcelona, Barcelona, Spain
| | - Maria-Antonia Poca
- Neurotraumatology and Neurosurgery Research Unit (UNINN), Vall d'Hebron University Hospital, Universidad Autònoma de Barcelona, Barcelona, Spain
- Department of Neurosurgery, Vall d'Hebron University Hospital, Universidad Autònoma de Barcelona, Barcelona, Spain
| | - Juan Sahuquillo
- Neurotraumatology and Neurosurgery Research Unit (UNINN), Vall d'Hebron University Hospital, Universidad Autònoma de Barcelona, Barcelona, Spain
- Department of Neurosurgery, Vall d'Hebron University Hospital, Universidad Autònoma de Barcelona, Barcelona, Spain
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Wetterling F, Chatzikonstantinou E, Tritschler L, Meairs S, Fatar M, Schad LR, Ansar S. Investigating potentially salvageable penumbra tissue in an in vivo model of transient ischemic stroke using sodium, diffusion, and perfusion magnetic resonance imaging. BMC Neurosci 2016; 17:82. [PMID: 27927188 PMCID: PMC5143461 DOI: 10.1186/s12868-016-0316-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 11/25/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Diffusion magnetic resonance imaging (MRI) is the current-state-of-the-art technique to clinically investigate acute (0-24 h) ischemic stroke tissue. However, reduced apparent diffusion coefficient (ADC)-considered a marker of tissue damage-was observed to reverse spontaneously during the subacute stroke phase (24-72 h) which means that low ADC cannot be used to reflect the damaged tissue after 24 h in experimental and clinical studies. One reason for the change in ADC is that ADC values drop with cytotoxic edema (acute phase) and rise when vasogenic edema begins (subacute phase). Recently, combined 1H- and 23Na-MRI was proposed as a more accurate approach to improve delineation between reversible (penumbra) and irreversible ischemic injury (core). The aim of this study was to investigate the effects of reperfusion on the ADC and the sodium MRI signal after experimental ischemic stroke in rats in well-defined areas of different viability levels of the cerebral lesion, i.e. core and penumbra as defined via perfusion and histology. Transient middle cerebral artery occlusion was induced in male rats by using the intraluminal filament technique. MRI sodium, perfusion and diffusion measurement was recorded before reperfusion, shortly after reperfusion and 24 h after reperfusion. The animals were reperfused after 90 min of ischemia. RESULTS Sodium signal in core did not change before reperfusion, increased after reperfusion while sodium signal in penumbra was significantly reduced before reperfusion, but showed no changes after reperfusion compared to control. The ADC was significantly decreased in core tissue at all three time points compared to contralateral side. This decrease recovered above commonly applied viability thresholds in the core after 24 h. CONCLUSIONS Reduced sodium-MRI signal in conjunction with reduced ADC can serve as a viability marker for penumbra detection and complement hydrogen diffusion- and perfusion-MRI in order to facilitate time-independent assessment of tissue fate and cellular bioenergetics failure in stroke patients.
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Affiliation(s)
- Friedrich Wetterling
- Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany.,Trinity Institute of Neuroscience, University of Dublin, Dublin, Ireland
| | - Eva Chatzikonstantinou
- Department of Neurology, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany
| | - Laurent Tritschler
- Department of Neurology, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany.,CESP, INSERM UMRS1178, Faculté de Pharmacie, University Paris-Sud, Université Paris-Saclay, 92296, Chatenay-Malabry, France
| | - Stephen Meairs
- Department of Neurology, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany
| | - Marc Fatar
- Department of Neurology, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany
| | - Lothar R Schad
- Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany
| | - Saema Ansar
- Department of Neurology, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany. .,Division of Experimental Vascular Research, Department of Clinical Sciences, Lund University, Sölvegatan 17, BMC A13, 22184, Lund, Sweden.
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15
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Muir KW, Macrae IM. Neuroimaging as a Selection Tool and Endpoint in Clinical and Pre-clinical Trials. Transl Stroke Res 2016; 7:368-77. [PMID: 27543177 PMCID: PMC5014902 DOI: 10.1007/s12975-016-0487-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 06/29/2016] [Accepted: 07/19/2016] [Indexed: 12/03/2022]
Abstract
Standard imaging in acute stroke enables the exclusion of non-stroke structural CNS lesions and cerebral haemorrhage from clinical and pre-clinical ischaemic stroke trials. In this review, the potential benefit of imaging (e.g., angiography and penumbral imaging) as a translational tool for trial recruitment and the use of imaging endpoints are discussed for both clinical and pre-clinical stroke research. The addition of advanced imaging to identify a “responder” population leads to reduced sample size for any given effect size in phase 2 trials and is a potentially cost-efficient means of testing interventions. In pre-clinical studies, technical failures (failed or incomplete vessel occlusion, cerebral haemorrhage) can be excluded early and continuous multimodal imaging of the animal from stroke onset is feasible. Pre- and post-intervention repeat scans provide real time assessment of the intervention over the first 4–6 h. Negative aspects of advanced imaging in animal studies include increased time under general anaesthesia, and, as in clinical studies, a delay in starting the intervention. In clinical phase 3 trial designs, the negative aspects of advanced imaging in patient selection include higher exclusion rates, slower recruitment, overestimated effect size and longer acquisition times. Imaging may identify biological effects with smaller sample size and at earlier time points, compared to standard clinical assessments, and can be adjusted for baseline parameters. Mechanistic insights can be obtained. Pre-clinically, multimodal imaging can non-invasively generate data on a range of parameters, allowing the animal to be recovered for subsequent behavioural testing and/or the brain taken for further molecular or histological analysis.
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Affiliation(s)
- Keith W Muir
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, Scotland, UK
| | - I Mhairi Macrae
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, Scotland, UK.
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16
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Biller A, Pflugmann I, Badde S, Diem R, Wildemann B, Nagel AM, Jordan J, Benkhedah N, Kleesiek J. Sodium MRI in Multiple Sclerosis is Compatible with Intracellular Sodium Accumulation and Inflammation-Induced Hyper-Cellularity of Acute Brain Lesions. Sci Rep 2016; 6:31269. [PMID: 27507776 PMCID: PMC4978993 DOI: 10.1038/srep31269] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 07/18/2016] [Indexed: 12/25/2022] Open
Abstract
The cascade of inflammatory pathogenetic mechanisms in multiple sclerosis (MS) has no specific conventional MRI correlates. Clinicians therefore stipulate improved imaging specificity to define the pathological substrates of MS in vivo including mapping of intracellular sodium accumulation. Based upon preclinical findings and results of previous sodium MRI studies in MS patients we hypothesized that the fluid-attenuated sodium signal differs between acute and chronic lesions. We acquired brain sodium and proton MRI data of N = 29 MS patients; lesion type was defined by the presence or absence of contrast enhancement. N = 302 MS brain lesions were detected, and generalized linear mixed models were applied to predict lesion type based on sodium signals; thereby controlling for varying numbers of lesions among patients and confounding variables such as age and medication. Hierarchical model comparisons revealed that both sodium signals average tissue (χ2(1) = 27.89, p < 0.001) and fluid-attenuated (χ2(1) = 5.76, p = 0.016) improved lesion type classification. Sodium MRI signals were significantly elevated in acute compared to chronic lesions compatible with intracellular sodium accumulation in acute MS lesions. If confirmed in further studies, sodium MRI could serve as biomarker for diagnostic assessment of MS, and as readout parameter in clinical trials promoting attenuation of chronic inflammation.
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Affiliation(s)
- Armin Biller
- Multi-Dimensional Medical Imaging Lab, Department of Neuroradiology, University of Heidelberg, 69120 Heidelberg, Germany.,Department of Radiology, German Cancer Research Centre (DKFZ), 69120 Heidelberg, Germany
| | - Isabella Pflugmann
- Multi-Dimensional Medical Imaging Lab, Department of Neuroradiology, University of Heidelberg, 69120 Heidelberg, Germany
| | - Stephanie Badde
- Department of Biological Psychology and Neuropsychology, University of Hamburg, 20146 Hamburg, Germany.,Department of Psychology, New York University, New York, NY 10003, USA
| | - Ricarda Diem
- Department of Neurology, University of Heidelberg, 69120 Heidelberg, Germany
| | - Brigitte Wildemann
- Molecular Neuroimmunology Group, Department of Neurology, University of Heidelberg, 69120 Heidelberg, Germany
| | - Armin M Nagel
- Division of Medical Physics in Radiology, German Cancer Research Centre (DKFZ), 69120 Heidelberg, Germany.,Department of Diagnostic and Interventional Radiology, University Medical Centre Ulm, 89070 Ulm, Germany.,Institute of Radiology, University Hospital Erlangen, 91054 Erlangen, Germany
| | - J Jordan
- Division of Medical Physics in Radiology, German Cancer Research Centre (DKFZ), 69120 Heidelberg, Germany.,Institute of Radiology, University Hospital Erlangen, 91054 Erlangen, Germany
| | - Nadia Benkhedah
- Division of Medical Physics in Radiology, German Cancer Research Centre (DKFZ), 69120 Heidelberg, Germany
| | - Jens Kleesiek
- Multi-Dimensional Medical Imaging Lab, Department of Neuroradiology, University of Heidelberg, 69120 Heidelberg, Germany.,Multidimensional Image Processing Group, HCI/IWR, University of Heidelberg, 69120 Heidelberg, Germany
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17
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Shah NJ, Worthoff WA, Langen KJ. Imaging of sodium in the brain: a brief review. NMR IN BIOMEDICINE 2016; 29:162-174. [PMID: 26451752 DOI: 10.1002/nbm.3389] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 07/30/2015] [Accepted: 08/07/2015] [Indexed: 06/05/2023]
Abstract
Sodium-based MRI plays a vital role in the study of metabolism and can unveil valuable information about emerging and existing pathology--in particular in the human brain. Sodium is the second most abundant MR active nucleus in living tissue and, due to its quadrupolar nature, has magnetic properties not common to conventional proton MRI, which can reveal further insights, such as information on the compartmental distribution of intra- and extracellular sodium. Nevertheless, the use of sodium nuclei for imaging comes at the expense of a lower sensitivity and significantly reduced relaxation times, making in vivo sodium studies feasible only at high magnetic field strength and by the use of dedicated pulse sequences. Hybrid imaging combining sodium MRI and positron emission tomography (PET) simultaneously is a novel and promising approach to access information on dynamic metabolism with much increased, PET-derived specificity. Application of this new methodology is demonstrated herein using examples from tumour imaging.
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Affiliation(s)
- N Jon Shah
- Institute of Neuroscience and Medicine-4, Forschungszentrum Juelich GmbH, 52425, Jülich, Germany
- Department of Neurology, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
- Jülich Aachen Research Alliance (JARA) - Translational Brain Medicine, Aachen and Jülich, Germany
| | - Wieland A Worthoff
- Institute of Neuroscience and Medicine-4, Forschungszentrum Juelich GmbH, 52425, Jülich, Germany
| | - Karl-Josef Langen
- Institute of Neuroscience and Medicine-4, Forschungszentrum Juelich GmbH, 52425, Jülich, Germany
- Jülich Aachen Research Alliance (JARA) - Translational Brain Medicine, Aachen and Jülich, Germany
- Department of Nuclear Medicine, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
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