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Jiang D, Lu H. Cerebral oxygen extraction fraction MRI: Techniques and applications. Magn Reson Med 2022; 88:575-600. [PMID: 35510696 PMCID: PMC9233013 DOI: 10.1002/mrm.29272] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 03/20/2022] [Accepted: 03/29/2022] [Indexed: 12/20/2022]
Abstract
The human brain constitutes 2% of the body's total mass but uses 20% of the oxygen. The rate of the brain's oxygen utilization can be derived from a knowledge of cerebral blood flow and the oxygen extraction fraction (OEF). Therefore, OEF is a key physiological parameter of the brain's function and metabolism. OEF has been suggested to be a useful biomarker in a number of brain diseases. With recent advances in MRI techniques, several MRI-based methods have been developed to measure OEF in the human brain. These MRI OEF techniques are based on the T2 of blood, the blood signal phase, the magnetic susceptibility of blood-containing voxels, the effect of deoxyhemoglobin on signal behavior in extravascular tissue, and the calibration of the BOLD signal using gas inhalation. Compared to 15 O PET, which is considered the "gold standard" for OEF measurement, MRI-based techniques are non-invasive, radiation-free, and are more widely available. This article provides a review of these emerging MRI-based OEF techniques. We first briefly introduce the role of OEF in brain oxygen homeostasis. We then review the methodological aspects of different categories of MRI OEF techniques, including their signal mechanisms, acquisition methods, and data analyses. The strengths and limitations of the techniques are discussed. Finally, we review key applications of these techniques in physiological and pathological conditions.
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Affiliation(s)
- Dengrong Jiang
- The Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Hanzhang Lu
- The Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA
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Martí-Bonmatí L, Rodríguez-Ortega A, Ten-Esteve A, Alberich-Bayarri Á, Celda B, Ferrer E. Quantification of H 217O by 1H-MR imaging at 3 T: a feasibility study. Eur Radiol Exp 2021; 5:56. [PMID: 34966953 PMCID: PMC8716803 DOI: 10.1186/s41747-021-00246-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 10/04/2021] [Indexed: 11/10/2022] Open
Abstract
Background Indirect 1H-magnetic resonance (MR) imaging of 17O-labelled water allows imaging in vivo dynamic changes in water compartmentalisation. Our aim was to describe the feasibility of indirect 1H-MR methods to evaluate the effect of H217O on the MR relaxation rates by using conventional a 3-T equipment and voxel-wise relaxation rates. Methods MR images were used to calculate the R1, R2, and R2* relaxation rates in phantoms (19 vials with different H217O concentrations, ranging from 0.039 to 5.5%). Afterwards, an experimental animal pilot study (8 rats) was designed to evaluate the in vivo relative R2 brain dynamic changes related to the intravenous administration of 17O-labelled water in rats. Results There were no significant changes on the R1 and R2* values from phantoms. The R2 obtained with the turbo spin-echo T2-weighted sequence with 20-ms echo time interval had the higher statistical difference (0.67 s−1, interquartile range 0.34, p < 0.001) and Spearman correlation (rho 0.79). The R2 increase was adjusted to a linear fit between 0.25 and 5.5%, represented with equation R2 = 0.405 concentration + 0.3215. The highest significant differences were obtained for the higher concentrations (3.1–5.5%). The rat brain MR experiment showed a mean 10% change in the R2 value after the H217O injection with progressive normalisation. Conclusions Indirect 1H-MR imaging method is able to measure H217O concentration by using R2 values and conventional 3-T MR equipment. Normalised R2 relative dynamic changes after the intravenous injection of a H217O saline solution provide a unique opportunity to map water pathophysiology in vivo, opening the analysis of aquaporins status and modifications by disease at clinically available 3-T proton MR scanners.
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Affiliation(s)
- Luis Martí-Bonmatí
- Biomedical Imaging Research Group (GIBI230) at La Fe Health Research Institute and Imaging La Fe node at Distributed Network for Biomedical Imaging (ReDIB) Unique Scientific and Technical Infrastructures (ICTS), La Fe University and Polytechnic Hospital, Av. Fernando Abril Martorell, 106, Torre E, Planta 0, 46026, Valencia, Spain.
| | - Alejandro Rodríguez-Ortega
- Biomedical Imaging Research Group (GIBI230) at La Fe Health Research Institute and Imaging La Fe node at Distributed Network for Biomedical Imaging (ReDIB) Unique Scientific and Technical Infrastructures (ICTS), La Fe University and Polytechnic Hospital, Av. Fernando Abril Martorell, 106, Torre E, Planta 0, 46026, Valencia, Spain
| | - Amadeo Ten-Esteve
- Biomedical Imaging Research Group (GIBI230) at La Fe Health Research Institute and Imaging La Fe node at Distributed Network for Biomedical Imaging (ReDIB) Unique Scientific and Technical Infrastructures (ICTS), La Fe University and Polytechnic Hospital, Av. Fernando Abril Martorell, 106, Torre E, Planta 0, 46026, Valencia, Spain
| | - Ángel Alberich-Bayarri
- Biomedical Imaging Research Group (GIBI230) at La Fe Health Research Institute and Imaging La Fe node at Distributed Network for Biomedical Imaging (ReDIB) Unique Scientific and Technical Infrastructures (ICTS), La Fe University and Polytechnic Hospital, Av. Fernando Abril Martorell, 106, Torre E, Planta 0, 46026, Valencia, Spain.,Quantitative Imaging Biomarkers in Medicine, QUIBIM SL, Valencia, Spain
| | - Bernardo Celda
- Physical Chemistry Department, University of Valencia, Valencia, Spain
| | - Eduardo Ferrer
- Radiotherapy Department, Hospital Clínico Universitario, Valencia, Spain
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Paech D, Nagel AM, Schultheiss MN, Umathum R, Regnery S, Scherer M, Wick A, Platt T, Wick W, Bendszus M, Unterberg A, Schlemmer HP, Ladd ME, Niesporek SC. Quantitative Dynamic Oxygen 17 MRI at 7.0 T for the Cerebral Oxygen Metabolism in Glioma. Radiology 2020; 295:181-189. [PMID: 32068505 DOI: 10.1148/radiol.2020191711] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Background Altered metabolism is a characteristic of cancer. Because of a shift in glucose metabolism from oxidative phosphorylation to lactate production for energy generation, malignant tumors are characterized by increased glycolysis followed by lactic acid fermentation, even in the presence of abundant oxygen (the Warburg effect). Purpose To quantitatively investigate dynamic oxygen 17 (17O) MRI in healthy participants and participants with untreated glioma to understand altered cerebral oxygen metabolism in glioma. Materials and Methods In this prospective study conducted from September 2016 to June 2018, individuals with newly diagnosed previously untreated glioma (World Health Organization grade II-IV) and healthy volunteers were included. Dynamic 17O MRI was performed with a 7.0-T whole-body system. 17O2 gas inhalation enabled dynamic measurement of the cerebral metabolic rate of oxygen (CMRO2) consumption. In healthy volunteers and participants with glioma, CMRO2 values in gray matter and white matter volumes were compared by using Wilcoxon signed rank tests. In participants with glioma, the tumor volume and tumor subcompartments were compared with normal-appearing gray matter and white matter by using Friedman test followed by Holm-Sidak post hoc tests. Results Ten participants (mean age, 42 years ± 18 [standard deviation]; nine men) with glioma and three healthy volunteers (mean age, 44 years ± 21; all men) were evaluated. CMRO2 was higher in normal-appearing gray matter compared with white matter in both participants with glioma (2.36 μmol/g/min ± 0.22 vs 0.75 μmol/g/min ± 0.10, respectively) and healthy volunteers (2.38 μmol/g/min ± 0.15 vs 0.63 μmol/g/min ± 0.05, respectively) (P < .001 and P = .03, respectively). In the tumor region, CMRO2 was reduced (high-grade tumor CMRO2, 0.23 μmol/g/min ± 0.07; low-grade tumor CMRO2, 0.39 μmol/g/min ± 0.16; overall CMRO2, 0.34 μmol/g/min ± 0.16) compared with normal-appearing gray matter (P < .001) and normal-appearing white matter (P < .001) in accordance with the Warburg theorem. Conclusion Dynamic oxygen 17 MRI method at 7.0 T as a direct metabolic imaging technique in glioma enabled quantitative visualization of the Warburg effect. A general reduction in oxidative glycolysis was observed in accordance with the Warburg theorem. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Rapalino in this issue.
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Affiliation(s)
- Daniel Paech
- From the Division of Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany (D.P., M.N.S., S.R., H.P.S.); Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany (A.M.N., R.U., T.P., M.E.L., S.C.N.); Institute of Radiology, University Hospital Erlangen, Erlangen, Germany (A.M.N.); Departments of Radiation Oncology (S.R.), Neurosurgery (M.S., A.U.), Neurology (A.W., W.W.), and Neuroradiology (M.B.), University Hospital Heidelberg, Heidelberg, Germany; and Faculty of Physics and Astronomy and Faculty of Medicine, University of Heidelberg, Heidelberg, Germany (M.E.L.)
| | - Armin M Nagel
- From the Division of Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany (D.P., M.N.S., S.R., H.P.S.); Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany (A.M.N., R.U., T.P., M.E.L., S.C.N.); Institute of Radiology, University Hospital Erlangen, Erlangen, Germany (A.M.N.); Departments of Radiation Oncology (S.R.), Neurosurgery (M.S., A.U.), Neurology (A.W., W.W.), and Neuroradiology (M.B.), University Hospital Heidelberg, Heidelberg, Germany; and Faculty of Physics and Astronomy and Faculty of Medicine, University of Heidelberg, Heidelberg, Germany (M.E.L.)
| | - Miriam N Schultheiss
- From the Division of Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany (D.P., M.N.S., S.R., H.P.S.); Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany (A.M.N., R.U., T.P., M.E.L., S.C.N.); Institute of Radiology, University Hospital Erlangen, Erlangen, Germany (A.M.N.); Departments of Radiation Oncology (S.R.), Neurosurgery (M.S., A.U.), Neurology (A.W., W.W.), and Neuroradiology (M.B.), University Hospital Heidelberg, Heidelberg, Germany; and Faculty of Physics and Astronomy and Faculty of Medicine, University of Heidelberg, Heidelberg, Germany (M.E.L.)
| | - Reiner Umathum
- From the Division of Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany (D.P., M.N.S., S.R., H.P.S.); Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany (A.M.N., R.U., T.P., M.E.L., S.C.N.); Institute of Radiology, University Hospital Erlangen, Erlangen, Germany (A.M.N.); Departments of Radiation Oncology (S.R.), Neurosurgery (M.S., A.U.), Neurology (A.W., W.W.), and Neuroradiology (M.B.), University Hospital Heidelberg, Heidelberg, Germany; and Faculty of Physics and Astronomy and Faculty of Medicine, University of Heidelberg, Heidelberg, Germany (M.E.L.)
| | - Sebastian Regnery
- From the Division of Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany (D.P., M.N.S., S.R., H.P.S.); Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany (A.M.N., R.U., T.P., M.E.L., S.C.N.); Institute of Radiology, University Hospital Erlangen, Erlangen, Germany (A.M.N.); Departments of Radiation Oncology (S.R.), Neurosurgery (M.S., A.U.), Neurology (A.W., W.W.), and Neuroradiology (M.B.), University Hospital Heidelberg, Heidelberg, Germany; and Faculty of Physics and Astronomy and Faculty of Medicine, University of Heidelberg, Heidelberg, Germany (M.E.L.)
| | - Moritz Scherer
- From the Division of Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany (D.P., M.N.S., S.R., H.P.S.); Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany (A.M.N., R.U., T.P., M.E.L., S.C.N.); Institute of Radiology, University Hospital Erlangen, Erlangen, Germany (A.M.N.); Departments of Radiation Oncology (S.R.), Neurosurgery (M.S., A.U.), Neurology (A.W., W.W.), and Neuroradiology (M.B.), University Hospital Heidelberg, Heidelberg, Germany; and Faculty of Physics and Astronomy and Faculty of Medicine, University of Heidelberg, Heidelberg, Germany (M.E.L.)
| | - Antje Wick
- From the Division of Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany (D.P., M.N.S., S.R., H.P.S.); Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany (A.M.N., R.U., T.P., M.E.L., S.C.N.); Institute of Radiology, University Hospital Erlangen, Erlangen, Germany (A.M.N.); Departments of Radiation Oncology (S.R.), Neurosurgery (M.S., A.U.), Neurology (A.W., W.W.), and Neuroradiology (M.B.), University Hospital Heidelberg, Heidelberg, Germany; and Faculty of Physics and Astronomy and Faculty of Medicine, University of Heidelberg, Heidelberg, Germany (M.E.L.)
| | - Tanja Platt
- From the Division of Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany (D.P., M.N.S., S.R., H.P.S.); Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany (A.M.N., R.U., T.P., M.E.L., S.C.N.); Institute of Radiology, University Hospital Erlangen, Erlangen, Germany (A.M.N.); Departments of Radiation Oncology (S.R.), Neurosurgery (M.S., A.U.), Neurology (A.W., W.W.), and Neuroradiology (M.B.), University Hospital Heidelberg, Heidelberg, Germany; and Faculty of Physics and Astronomy and Faculty of Medicine, University of Heidelberg, Heidelberg, Germany (M.E.L.)
| | - Wolfgang Wick
- From the Division of Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany (D.P., M.N.S., S.R., H.P.S.); Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany (A.M.N., R.U., T.P., M.E.L., S.C.N.); Institute of Radiology, University Hospital Erlangen, Erlangen, Germany (A.M.N.); Departments of Radiation Oncology (S.R.), Neurosurgery (M.S., A.U.), Neurology (A.W., W.W.), and Neuroradiology (M.B.), University Hospital Heidelberg, Heidelberg, Germany; and Faculty of Physics and Astronomy and Faculty of Medicine, University of Heidelberg, Heidelberg, Germany (M.E.L.)
| | - Martin Bendszus
- From the Division of Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany (D.P., M.N.S., S.R., H.P.S.); Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany (A.M.N., R.U., T.P., M.E.L., S.C.N.); Institute of Radiology, University Hospital Erlangen, Erlangen, Germany (A.M.N.); Departments of Radiation Oncology (S.R.), Neurosurgery (M.S., A.U.), Neurology (A.W., W.W.), and Neuroradiology (M.B.), University Hospital Heidelberg, Heidelberg, Germany; and Faculty of Physics and Astronomy and Faculty of Medicine, University of Heidelberg, Heidelberg, Germany (M.E.L.)
| | - Andreas Unterberg
- From the Division of Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany (D.P., M.N.S., S.R., H.P.S.); Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany (A.M.N., R.U., T.P., M.E.L., S.C.N.); Institute of Radiology, University Hospital Erlangen, Erlangen, Germany (A.M.N.); Departments of Radiation Oncology (S.R.), Neurosurgery (M.S., A.U.), Neurology (A.W., W.W.), and Neuroradiology (M.B.), University Hospital Heidelberg, Heidelberg, Germany; and Faculty of Physics and Astronomy and Faculty of Medicine, University of Heidelberg, Heidelberg, Germany (M.E.L.)
| | - Heinz-Peter Schlemmer
- From the Division of Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany (D.P., M.N.S., S.R., H.P.S.); Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany (A.M.N., R.U., T.P., M.E.L., S.C.N.); Institute of Radiology, University Hospital Erlangen, Erlangen, Germany (A.M.N.); Departments of Radiation Oncology (S.R.), Neurosurgery (M.S., A.U.), Neurology (A.W., W.W.), and Neuroradiology (M.B.), University Hospital Heidelberg, Heidelberg, Germany; and Faculty of Physics and Astronomy and Faculty of Medicine, University of Heidelberg, Heidelberg, Germany (M.E.L.)
| | - Mark E Ladd
- From the Division of Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany (D.P., M.N.S., S.R., H.P.S.); Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany (A.M.N., R.U., T.P., M.E.L., S.C.N.); Institute of Radiology, University Hospital Erlangen, Erlangen, Germany (A.M.N.); Departments of Radiation Oncology (S.R.), Neurosurgery (M.S., A.U.), Neurology (A.W., W.W.), and Neuroradiology (M.B.), University Hospital Heidelberg, Heidelberg, Germany; and Faculty of Physics and Astronomy and Faculty of Medicine, University of Heidelberg, Heidelberg, Germany (M.E.L.)
| | - Sebastian C Niesporek
- From the Division of Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany (D.P., M.N.S., S.R., H.P.S.); Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany (A.M.N., R.U., T.P., M.E.L., S.C.N.); Institute of Radiology, University Hospital Erlangen, Erlangen, Germany (A.M.N.); Departments of Radiation Oncology (S.R.), Neurosurgery (M.S., A.U.), Neurology (A.W., W.W.), and Neuroradiology (M.B.), University Hospital Heidelberg, Heidelberg, Germany; and Faculty of Physics and Astronomy and Faculty of Medicine, University of Heidelberg, Heidelberg, Germany (M.E.L.)
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Berkowitz BA, Olds HK, Richards C, Joy J, Rosales T, Podolsky RH, Childers KL, Hubbard WB, Sullivan PG, Gao S, Li Y, Qian H, Roberts R. Novel imaging biomarkers for mapping the impact of mild mitochondrial uncoupling in the outer retina in vivo. PLoS One 2020; 15:e0226840. [PMID: 31923239 PMCID: PMC6953833 DOI: 10.1371/journal.pone.0226840] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 12/05/2019] [Indexed: 12/14/2022] Open
Abstract
PURPOSE To test the hypothesis that imaging biomarkers are useful for evaluating in vivo rod photoreceptor cell responses to a mitochondrial protonophore. METHODS Intraperitoneal injections of either the mitochondrial uncoupler 2,4 dinitrophenol (DNP) or saline were given to mice with either higher [129S6/eVTac (S6)] or lower [C57BL/6J (B6)] mitochondrial reserve capacities and were studied in dark or light. We measured: (i) the external limiting membrane-retinal pigment epithelium region thickness (ELM-RPE; OCT), which decreases substantially with upregulation of a pH-sensitive water removal co-transporter on the apical portion of the RPE, and (ii) the outer retina R1 (= 1/(spin lattice relaxation time (T1), an MRI parameter proportional to oxygen / free radical content. RESULTS In darkness, baseline rod energy production and consumption are relatively high compared to that in light, and additional metabolic stimulation with DNP provoked thinning of the ELM-RPE region compared to saline injection in S6 mice; ELM-RPE thickness was unresponsive to DNP in B6 mice. Also, dark-adapted S6 mice given DNP showed a decrease in outer retina R1 values compared to saline injection in the inferior retina. In dark-adapted B6 mice, transretinal R1 values were unresponsive to DNP in superior and inferior regions. In light, with its relatively lower basal rod energy production and consumption, DNP caused ELM-RPE thinning in both S6 and B6 mice. CONCLUSIONS The present results raise the possibility of non-invasively evaluating the mouse rod mitochondrial energy ecosystem using new DNP-assisted OCT and MRI in vivo assays.
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Affiliation(s)
- Bruce A. Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States of America
- * E-mail:
| | - Hailey K. Olds
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Collin Richards
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Joydip Joy
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Tilman Rosales
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Robert H. Podolsky
- Beaumont Research Institute, Beaumont Health, Royal Oak, MI, United States of America
| | - Karen Lins Childers
- Beaumont Research Institute, Beaumont Health, Royal Oak, MI, United States of America
| | - W. Brad Hubbard
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, United States of America
- Department of Neuroscience, University of Kentucky, Lexington, KY, United States of America
| | - Patrick G. Sullivan
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, United States of America
- Department of Neuroscience, University of Kentucky, Lexington, KY, United States of America
- Lexington VA Health Care System, Lexington, KY, United States of America
| | - Shasha Gao
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD, United States of America
- Department of Ophthalmology, First Affiliated Hospital, Zhengzhou University, Zhengzhou, China
| | - Yichao Li
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD, United States of America
| | - Haohua Qian
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD, United States of America
| | - Robin Roberts
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States of America
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Niesporek SC, Umathum R, Lommen JM, Behl NG, Paech D, Bachert P, Ladd ME, Nagel AM. Reproducibility of CMRO2determination using dynamic17O MRI. Magn Reson Med 2017; 79:2923-2934. [DOI: 10.1002/mrm.26952] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 09/07/2017] [Accepted: 09/10/2017] [Indexed: 12/15/2022]
Affiliation(s)
- Sebastian C. Niesporek
- Division of Medical Physics in Radiology; German Cancer Research Center (DKFZ); Heidelberg Germany
| | - Reiner Umathum
- Division of Medical Physics in Radiology; German Cancer Research Center (DKFZ); Heidelberg Germany
| | - Jonathan M. Lommen
- Division of Medical Physics in Radiology; German Cancer Research Center (DKFZ); Heidelberg Germany
| | - Nicolas G.R. Behl
- Division of Medical Physics in Radiology; German Cancer Research Center (DKFZ); Heidelberg Germany
| | - Daniel Paech
- Division of Radiology; German Cancer Research Center (DKFZ); Heidelberg Germany
| | - Peter Bachert
- Division of Medical Physics in Radiology; German Cancer Research Center (DKFZ); Heidelberg Germany
- Faculty of Physics and Astronomy; University of Heidelberg; Heidelberg Germany
| | - Mark E. Ladd
- Division of Medical Physics in Radiology; German Cancer Research Center (DKFZ); Heidelberg Germany
- Faculty of Physics and Astronomy; University of Heidelberg; Heidelberg Germany
- Faculty of Medicine; University of Heidelberg; Heidelberg Germany
| | - Armin M. Nagel
- Division of Medical Physics in Radiology; German Cancer Research Center (DKFZ); Heidelberg Germany
- Institute of Radiology; University Hospital Erlangen; Erlangen Germany
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Neveu MA, Joudiou N, De Preter G, Dehoux JP, Jordan BF, Gallez B. 17 O MRS assesses the effect of mild hypothermia on oxygen consumption rate in tumors. NMR IN BIOMEDICINE 2017; 30:e3726. [PMID: 28430379 DOI: 10.1002/nbm.3726] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 02/17/2017] [Accepted: 02/27/2017] [Indexed: 06/07/2023]
Abstract
Although oxygen consumption is a key factor in metabolic phenotyping, its assessment in tumors remains critical, as current technologies generally display poor specificity. The objectives of this study were to explore the feasibility of direct 17 O nuclear magnetic resonance (NMR) spectroscopy to assess oxygen metabolism in tumors and its modulations. To investigate the impact of hypometabolism induction in the murine fibrosarcoma FSAII tumor model, we monitored the oxygen consumption of normothermic (37°C) and hypothermic (32°C) tumor-bearing mice. Hypothermic animals showed an increase in tumor pO2 (measured by electron paramagnetic resonance oximetry) contrary to normothermic animals. This was related to a decrease in oxygen consumption rate (assessed using 17 O magnetic resonance spectroscopy (MRS) after the inhalation of 17 O2 -enriched gas). This study highlights the ability of direct 17 O MRS to measure oxygen metabolism in tumors and modulations of tumor oxygen consumption rate.
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Affiliation(s)
- Marie-Aline Neveu
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute (LDRI), Université catholique de Louvain (UCL), Belgium
| | - Nicolas Joudiou
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute (LDRI), Université catholique de Louvain (UCL), Belgium
| | - Géraldine De Preter
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute (LDRI), Université catholique de Louvain (UCL), Belgium
| | - Jean-Paul Dehoux
- Experimental Surgery Unit, Medical School, Institute of Experimental and Clinical Research (IREC), Université catholique de Louvain (UCL), Belgium
| | - Bénédicte F Jordan
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute (LDRI), Université catholique de Louvain (UCL), Belgium
| | - Bernard Gallez
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute (LDRI), Université catholique de Louvain (UCL), Belgium
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7
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Wehrli FW, Fan AP, Rodgers ZB, Englund EK, Langham MC. Susceptibility-based time-resolved whole-organ and regional tissue oximetry. NMR IN BIOMEDICINE 2017; 30:10.1002/nbm.3495. [PMID: 26918319 PMCID: PMC5001941 DOI: 10.1002/nbm.3495] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 12/18/2015] [Accepted: 01/06/2016] [Indexed: 05/15/2023]
Abstract
The magnetism of hemoglobin - being paramagnetic in its deoxy and diamagnetic in its oxy state - offers unique opportunities to probe oxygen metabolism in blood and tissues. The magnetic susceptibility χ of blood scales linearly with blood oxygen saturation, which can be obtained by measuring the magnetic field ΔB of the intravascular MR signal relative to tissue. In contrast to χ, the induced field ΔB is non-local. Therefore, to obtain the intravascular susceptibility Δχ relative to adjoining tissue from the measured ΔB demands solution of an inverse problem. Fortunately, for ellipsoidal structures, to which a straight, cylindrically shaped blood vessel segment conforms, the solution is trivial. The article reviews the principle of MR susceptometry-based blood oximetry. It then discusses applications for quantification of whole-brain oxygen extraction - typically on the basis of a measurement in the superior sagittal sinus - and, in conjunction with total cerebral blood flow, the cerebral metabolic rate of oxygen (CMRO2 ). By simultaneously measuring flow and venous oxygen saturation (SvO2 ) a temporal resolution of a few seconds can be achieved, allowing the study of the response to non-steady-state challenges such as volitional apnea. Extensions to regional measurements in smaller cerebral veins are also possible, as well as voxelwise quantification of venous blood saturation in cerebral veins accomplished by quantitative susceptibility mapping (QSM) techniques. Applications of susceptometry-based oximetry to studies of metabolic and degenerative disorders of the brain are reviewed. Lastly, the technique is shown to be applicable to other organ systems such as the extremities using SvO2 as a dynamic tracer to monitor the kinetics of the microvascular response to induced ischemia. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Felix W Wehrli
- Laboratory for Structural, Physiologic and Functional Imaging, Department of Radiology, Perelman School of Medicine, University of Pennsylvania
| | - Audrey P Fan
- Lucas Center for Imaging, Department of Radiology, Stanford University, James H. Clark Center, 318 Campus Drive, Suite S170, Stanford, CA 94305
| | - Zachary B Rodgers
- Laboratory for Structural, Physiologic and Functional Imaging, Department of Radiology, Perelman School of Medicine, University of Pennsylvania
| | - Erin K Englund
- Laboratory for Structural, Physiologic and Functional Imaging, Department of Radiology, Perelman School of Medicine, University of Pennsylvania
| | - Michael C Langham
- Laboratory for Structural, Physiologic and Functional Imaging, Department of Radiology, Perelman School of Medicine, University of Pennsylvania
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8
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Kurzhunov D, Borowiak R, Hass H, Wagner P, Krafft AJ, Timmer J, Bock M. Quantification of oxygen metabolic rates in Human brain with dynamic 17 O MRI: Profile likelihood analysis. Magn Reson Med 2016; 78:1157-1167. [PMID: 27804163 DOI: 10.1002/mrm.26476] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 07/28/2016] [Accepted: 09/01/2016] [Indexed: 11/11/2022]
Abstract
PURPOSE Parameter identifiability and confidence intervals were determined using a profile likelihood (PL) analysis method in a quantification model of the cerebral metabolic rate of oxygen consumption (CMRO2 ) with direct 17 O MRI. METHODS Three-dimensional dynamic 17 O MRI datasets of the human brain were acquired after inhalation of 17 O2 gas with the help of a rebreathing system, and CMRO2 was quantified with a pharmacokinetic model. To analyze the influence of the different model parameters on the identifiability of CMRO2 , PLs were calculated for different settings of the model parameters. In particular, the 17 O enrichment fraction of the inhaled 17 O2 gas, α, was investigated assuming a constant and a linearly varying model. Identifiability was analyzed for white and gray matter, and the dependency on different priors was studied. RESULTS Prior knowledge about only one α-related parameter was sufficient to resolve the CMRO2 nonidentifiability, and CMRO2 rates (0.72-0.99 µmol/gtissue /min in white matter, 1.02-1.78 µmol/gtissue /min in gray matter) are in a good agreement with the results of 15 O positron emission tomography studies. Nonconstant α values significantly improved model fitting. CONCLUSION The profile likelihood analysis shows that CMRO2 can be measured reliably in 17 O gas MRI experiment if the 17 O enrichment fraction is used as prior information for the model calculations. Magn Reson Med 78:1157-1167, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Dmitry Kurzhunov
- Department of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Robert Borowiak
- Department of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany.,German Cancer Consortium, Heidelberg, Germany.,German Cancer Research Center, Heidelberg, Germany
| | - Helge Hass
- Institute of Physics, University of Freiburg, Freiburg, Germany
| | - Philipp Wagner
- Department of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Axel Joachim Krafft
- Department of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany.,German Cancer Consortium, Heidelberg, Germany.,German Cancer Research Center, Heidelberg, Germany
| | - Jens Timmer
- Institute of Physics, University of Freiburg, Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Michael Bock
- Department of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
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9
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Lou S, Lepak VC, Eberly LE, Roth B, Cui W, Zhu XH, Öz G, Dubinsky JM. Oxygen consumption deficit in Huntington disease mouse brain under metabolic stress. Hum Mol Genet 2016; 25:2813-2826. [PMID: 27193167 DOI: 10.1093/hmg/ddw138] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 04/18/2016] [Accepted: 05/03/2016] [Indexed: 01/28/2023] Open
Abstract
In vivo evidence for brain mitochondrial dysfunction in animal models of Huntington disease (HD) is scarce. We applied the novel 17O magnetic resonance spectroscopy (MRS) technique on R6/2 mice to directly determine rates of oxygen consumption (CMRO2) and assess mitochondrial function in vivo Basal respiration and maximal CMRO2 in the presence of the mitochondrial uncoupler dinitrophenol (DNP) were compared using 16.4 T in isoflurane anesthetized wild type (WT) and HD mice at 9 weeks. At rest, striatal CMRO2 of R6/2 mice was equivalent to that of WT, indicating comparable mitochondrial output despite onset of motor symptoms in R6/2. After DNP injection, the maximal CMRO2 in both striatum and cortex of R6/2 mice was significantly lower than that of WT, indicating less spare energy generating capacity. In a separate set of mice, oligomycin injection to block ATP generation decreased CMRO2 equally in brains of R6/2 and WT mice, suggesting oxidative phosphorylation capacity and respiratory coupling were equivalent at rest. Expression levels of representative mitochondrial proteins were compared from harvested tissue samples. Significant differences between R6/2 and WT included: in striatum, lower VDAC and the mitochondrially encoded cytochrome oxidase subunit I relative to actin; in cortex, lower tricarboxylic acid cycle enzyme aconitase and higher protein carbonyls; in both, lower glycolytic enzyme enolase. Therefore in R6/2 striatum, lowered CMRO2 may be attributed to a decrease in mitochondria while the cortical CMRO2 decrease may result from constraints upstream in energetic pathways, suggesting regionally specific changes and possibly rates of metabolic impairment.
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Affiliation(s)
| | | | | | | | - Weina Cui
- Center for MR Research, Department of Radiology, Medical School, University of Minnesota, Minneapolis, MN, USA
| | - Xiao-Hong Zhu
- Center for MR Research, Department of Radiology, Medical School, University of Minnesota, Minneapolis, MN, USA
| | - Gülin Öz
- Center for MR Research, Department of Radiology, Medical School, University of Minnesota, Minneapolis, MN, USA
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10
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Baker WB, Parthasarathy AB, Busch DR, Mesquita RC, Greenberg JH, Yodh AG. Modified Beer-Lambert law for blood flow. BIOMEDICAL OPTICS EXPRESS 2014; 5:4053-75. [PMID: 25426330 PMCID: PMC4242038 DOI: 10.1364/boe.5.004053] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 10/14/2014] [Accepted: 10/15/2014] [Indexed: 05/18/2023]
Abstract
We develop and validate a Modified Beer-Lambert law for blood flow based on diffuse correlation spectroscopy (DCS) measurements. The new formulation enables blood flow monitoring from temporal intensity autocorrelation function data taken at single or multiple delay-times. Consequentially, the speed of the optical blood flow measurement can be substantially increased. The scheme facilitates blood flow monitoring of highly scattering tissues in geometries wherein light propagation is diffusive or non-diffusive, and it is particularly well-suited for utilization with pressure measurement paradigms that employ differential flow signals to reduce contributions of superficial tissues.
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Affiliation(s)
- Wesley B. Baker
- Dept. Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104,
USA
| | | | - David R. Busch
- Dept. Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104,
USA
- Div. of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104,
USA
| | - Rickson C. Mesquita
- Institute of Physics, University of Campinas, Campinas, SP 13083-859,
Brazil
| | - Joel H. Greenberg
- Dept. Neurology, University of Pennsylvania, Philadelphia, PA 19104,
USA
| | - A. G. Yodh
- Dept. Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104,
USA
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11
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Andronesi OC, Bhat H, Reuter M, Mukherjee S, Caravan P, Rosen BR. Whole brain mapping of water pools and molecular dynamics with rotating frame MR relaxation using gradient modulated low-power adiabatic pulses. Neuroimage 2013; 89:92-109. [PMID: 24345390 DOI: 10.1016/j.neuroimage.2013.12.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 11/27/2013] [Accepted: 12/07/2013] [Indexed: 10/25/2022] Open
Abstract
Nuclear magnetic resonance (NMR) relaxation in the rotating frame is sensitive to molecular dynamics on the time scale of water molecules interacting with macromolecules or supramolecular complexes, such as proteins, myelin and cell membranes. Hence, longitudinal (T1ρ) and transverse (T2ρ) relaxation in the rotating frame may have a great potential to probe the macromolecular fraction of tissues. This stimulated a large interest in using this MR contrast to image brain under healthy and disease conditions. However, experimental challenges related to the use of intense radiofrequency irradiation have limited the widespread use of T1ρ and T2ρ imaging. Here, we present methodological development to acquire 3D high-resolution or 2D (multi-)slice selective T1ρ and T2ρ maps of the entire human brain within short acquisition times. These improvements are based on a class of gradient modulated adiabatic pulses that reduce the power deposition, provide slice selection, and mitigate artifacts resulting from inhomogeneities of B1 and B0 magnetic fields. Based on an analytical model of the T1ρ and T2ρ relaxation we compute the maps of macromolecular bound water fraction, correlation and exchange time constants as quantitative biomarkers informative of tissue macromolecular content. Results obtained from simulations, phantoms and five healthy subjects are included.
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Affiliation(s)
- Ovidiu C Andronesi
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
| | - Himanshu Bhat
- Siemens Medical Solutions USA Inc, Charlestown, MA 02129, USA
| | - Martin Reuter
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Shreya Mukherjee
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Peter Caravan
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Bruce R Rosen
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
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12
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Characterizing cerebral oxygen metabolism employing oxygen-17 MRI/MRS at high fields. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2013; 27:81-93. [DOI: 10.1007/s10334-013-0413-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 09/06/2013] [Accepted: 10/07/2013] [Indexed: 10/25/2022]
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13
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Direct cerebral and cardiac 17O-MRI at 3 Tesla: initial results at natural abundance. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2013; 27:95-9. [DOI: 10.1007/s10334-013-0409-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 07/04/2013] [Accepted: 08/30/2013] [Indexed: 10/26/2022]
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14
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Zhu XH, Chen JM, Tu TW, Chen W, Song SK. Simultaneous and noninvasive imaging of cerebral oxygen metabolic rate, blood flow and oxygen extraction fraction in stroke mice. Neuroimage 2013; 64:437-47. [PMID: 23000789 PMCID: PMC3508145 DOI: 10.1016/j.neuroimage.2012.09.028] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2012] [Revised: 07/19/2012] [Accepted: 09/12/2012] [Indexed: 10/27/2022] Open
Abstract
Many brain diseases have been linked to abnormal oxygen metabolism and blood perfusion; nevertheless, there is still a lack of robust diagnostic tools for directly imaging cerebral metabolic rate of oxygen (CMRO(2)) and cerebral blood flow (CBF), as well as the oxygen extraction fraction (OEF) that reflects the balance between CMRO(2) and CBF. This study employed the recently developed in vivo (17)O MR spectroscopic imaging to simultaneously assess CMRO(2), CBF and OEF in the brain using a preclinical middle cerebral arterial occlusion mouse model with a brief inhalation of (17)O-labeled oxygen gas. The results demonstrated high sensitivity and reliability of the noninvasive (17)O-MR approach for rapidly imaging CMRO(2), CBF and OEF abnormalities in the ischemic cortex of the MCAO mouse brain. It was found that in the ischemic brain regions both CMRO(2) and CBF were substantially lower than that of intact brain regions, even for the mildly damaged brain regions that were unable to be clearly identified by the conventional MRI. In contrast, OEF was higher in the MCAO affected brain regions. This study demonstrates a promising (17)O MRI technique for imaging abnormal oxygen metabolism and perfusion in the diseased brain regions. This (17)O MRI technique is advantageous because of its robustness, simplicity, noninvasiveness and reliability: features that are essential to potentially translate it to human patients for early diagnosis and monitoring of treatment efficacy.
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Affiliation(s)
- Xiao-Hong Zhu
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
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15
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Metabolic Imaging in Translational Stroke Research. Transl Stroke Res 2012. [DOI: 10.1007/978-1-4419-9530-8_41] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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16
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Bulte DP, Kelly M, Germuska M, Xie J, Chappell MA, Okell TW, Bright MG, Jezzard P. Quantitative measurement of cerebral physiology using respiratory-calibrated MRI. Neuroimage 2011; 60:582-91. [PMID: 22209811 DOI: 10.1016/j.neuroimage.2011.12.017] [Citation(s) in RCA: 163] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 12/08/2011] [Accepted: 12/11/2011] [Indexed: 11/26/2022] Open
Abstract
Functional magnetic resonance imaging typically measures signal increases arising from changes in the transverse relaxation rate over small regions of the brain and associates these with local changes in cerebral blood flow, blood volume and oxygen metabolism. Recent developments in pulse sequences and image analysis methods have improved the specificity of the measurements by focussing on changes in blood flow or changes in blood volume alone. However, FMRI is still unable to match the physiological information obtainable from positron emission tomography (PET), which is capable of quantitative measurements of blood flow and volume, and can indirectly measure resting metabolism. The disadvantages of PET are its cost, its availability, its poor spatial resolution and its use of ionising radiation. The MRI techniques introduced here address some of these limitations and provide physiological data comparable with PET measurements. We present an 18-minute MRI protocol that produces multi-slice whole-brain coverage and yields quantitative images of resting cerebral blood flow, cerebral blood volume, oxygen extraction fraction, CMRO(2), arterial arrival time and cerebrovascular reactivity of the human brain in the absence of any specific functional task. The technique uses a combined hyperoxia and hypercapnia paradigm with a modified arterial spin labelling sequence.
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Affiliation(s)
- D P Bulte
- FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
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17
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Zhu XH, Chen W. In vivo oxygen-17 NMR for imaging brain oxygen metabolism at high field. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2011; 59:319-35. [PMID: 22027341 PMCID: PMC3202696 DOI: 10.1016/j.pnmrs.2011.04.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Accepted: 04/14/2011] [Indexed: 05/14/2023]
Affiliation(s)
- Xiao-Hong Zhu
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, 2021 6th St. SE, Minneapolis, MN 55455, USA.
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18
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Hoffmann SH, Begovatz P, Nagel AM, Umathum R, Schommer K, Bachert P, Bock M. A measurement setup for direct 17
O MRI at 7 T. Magn Reson Med 2011; 66:1109-15. [DOI: 10.1002/mrm.22871] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Revised: 01/15/2011] [Accepted: 01/18/2011] [Indexed: 11/05/2022]
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Abstract
Two new large animal models of Huntington's disease (HD) have been developed recently, an old world monkey (macaque) and a sheep. Macaques, with their large brains and complex repertoire of behaviors are the 'gold-standard' laboratory animals for testing cognitive function, but there are many practical and ethical issues that must be resolved before HD macaques can be used for pre-clinical research. By contrast, despite their comparable brain size, sheep do not enjoy a reputation for intelligence, and are not used for pre-clinical cognitive testing. Given that cognitive decline is a major therapeutic target in HD, the feasibility of testing cognitive function in sheep must be explored if they are to be considered seriously as models of HD. Here we tested the ability of sheep to perform tests of executive function (discrimination learning, reversal learning and attentional set-shifting). Significantly, we found that not only could sheep perform discrimination learning and reversals, but they could also perform the intradimensional (ID) and extradimensional (ED) set-shifting tasks that are sensitive tests of cognitive dysfunction in humans. Their performance on the ID/ED shifts mirrored that seen in humans and macaques, with significantly more errors to reach criterion in the ED than the ID shift. Thus, sheep can perform 'executive' cognitive tasks that are an important part of the primate behavioral repertoire, but which have never been shown previously to exist in any other large animal. Sheep have great potential, not only for use as a large animal model of HD, but also for studying cognitive function and the evolution of complex behaviours in normal animals.
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Affiliation(s)
- A Jennifer Morton
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom.
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