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Ebersberger L, Kratzer FJ, Potreck A, Niesporek SC, Keymling M, Nagel AM, Bendszus M, Wick W, Ladd ME, Schlemmer HP, Hoffmann A, Platt T, Paech D. First application of dynamic oxygen-17 magnetic resonance imaging at 7 Tesla in a patient with early subacute stroke. Front Neurosci 2023; 17:1186558. [PMID: 37404469 PMCID: PMC10317041 DOI: 10.3389/fnins.2023.1186558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 05/26/2023] [Indexed: 07/06/2023] Open
Abstract
Dynamic oxygen-17 (17O) magnetic resonance imaging (MRI) is an imaging method that enables a direct and non-invasive assessment of cerebral oxygen metabolism and thus potentially the distinction between viable and non-viable tissue employing a three-phase inhalation experiment. The purpose of this investigation was the first application of dynamic 17O MRI at 7 Tesla (T) in a patient with stroke. In this proof-of-concept experiment, dynamic 17O MRI was applied during 17O inhalation in a patient with early subacute stroke. The analysis of the relative 17O water (H217O) signal for the affected stroke region compared to the healthy contralateral side revealed no significant difference. However, the technical feasibility of 17O MRI has been demonstrated paving the way for future investigations in neurovascular diseases.
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Affiliation(s)
- Louise Ebersberger
- Division of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Faculty of Medicine, University of Heidelberg, Heidelberg, Germany
| | - Fabian J. Kratzer
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Arne Potreck
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Sebastian C. Niesporek
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Myriam Keymling
- Division of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Armin M. Nagel
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Institute of Radiology, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen University Hospital, Erlangen, Germany
| | - Martin Bendszus
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Wolfgang Wick
- Department of Neurology, Heidelberg University Hospital, Heidelberg, Germany
| | - Mark E. Ladd
- Faculty of Medicine, University of Heidelberg, Heidelberg, Germany
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Faculty of Physics and Astronomy, University of Heidelberg, Heidelberg, Germany
| | | | - Angelika Hoffmann
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
- Department of Neuroradiology, Bern University Hospital, Bern, Switzerland
| | - Tanja Platt
- 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
- Department of Neuroradiology, Bonn University Hospital, Bonn, Germany
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2
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Knowles BR, Friedrich F, Fischer C, Paech D, Ladd ME. Beyond T2 and 3T: New MRI techniques for clinicians. Clin Transl Radiat Oncol 2019; 18:87-97. [PMID: 31341982 PMCID: PMC6630188 DOI: 10.1016/j.ctro.2019.04.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 04/11/2019] [Accepted: 04/11/2019] [Indexed: 12/12/2022] Open
Abstract
Technological advances in Magnetic Resonance Imaging (MRI) in terms of field strength and hybrid MR systems have led to improvements in tumor imaging in terms of anatomy and functionality. This review paper discusses the applications of such advances in the field of radiation oncology with regards to treatment planning, therapy guidance and monitoring tumor response and predicting outcome.
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Affiliation(s)
- Benjamin R. Knowles
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Florian Friedrich
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Physics and Astronomy, University of Heidelberg, Heidelberg, Germany
| | - Carola Fischer
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Physics and Astronomy, University of Heidelberg, Heidelberg, Germany
| | - Daniel Paech
- Department of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Mark E. Ladd
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Physics and Astronomy, University of Heidelberg, Heidelberg, Germany
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3
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Zhu XH, Lu M, Chen W. Quantitative imaging of brain energy metabolisms and neuroenergetics using in vivo X-nuclear 2H, 17O and 31P MRS at ultra-high field. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 292:155-170. [PMID: 29866434 PMCID: PMC5996770 DOI: 10.1016/j.jmr.2018.05.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 04/27/2018] [Accepted: 05/08/2018] [Indexed: 05/13/2023]
Abstract
Brain energy metabolism relies predominantly on glucose and oxygen utilization to generate biochemical energy in the form of adenosine triphosphate (ATP). ATP is essential for maintaining basal electrophysiological activities in a resting brain and supporting evoked neuronal activity under an activated state. Studying complex neuroenergetic processes in the brain requires sophisticated neuroimaging techniques enabling noninvasive and quantitative assessment of cerebral energy metabolisms and quantification of metabolic rates. Recent state-of-the-art in vivo X-nuclear MRS techniques, including 2H, 17O and 31P MRS have shown promise, especially at ultra-high fields, in the quest for understanding neuroenergetics and brain function using preclinical models and in human subjects under healthy and diseased conditions.
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Affiliation(s)
- Xiao-Hong Zhu
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, School of Medicine, Minneapolis, MN 55455, USA
| | - Ming Lu
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, School of Medicine, Minneapolis, MN 55455, USA
| | - Wei Chen
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, School of Medicine, Minneapolis, MN 55455, USA.
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4
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Improved
$$T_{2}^{*}$$
T
2
∗
determination in 23Na, 35Cl, and 17O MRI using iterative partial volume correction based on 1H MRI segmentation. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2017; 30:519-536. [DOI: 10.1007/s10334-017-0623-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 04/06/2017] [Accepted: 04/19/2017] [Indexed: 12/25/2022]
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5
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Zhu XH, Chen W. In vivo 17O MRS imaging - Quantitative assessment of regional oxygen consumption and perfusion rates in living brain. Anal Biochem 2016; 529:171-178. [PMID: 27568551 DOI: 10.1016/j.ab.2016.08.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 08/22/2016] [Accepted: 08/24/2016] [Indexed: 10/21/2022]
Abstract
In the last decade, in vivo oxygen-17 (17O) MRS has evolved into a promising MR technique for noninvasively studying oxygen metabolism and perfusion in aerobic organs with the capability of imaging the regional metabolic rate of oxygen and its changes. In this chapter, we will briefly review the methodology of the in vivo17O MRS technique and its recent development and applications; we will also discuss the advantages of the high/ultrahigh magnetic field for 17O MR detection, as well as the challenges and potential of this unique MRS method for biomedical research of oxygen metabolism, mitochondrial function and tissue energetics in health and disease.
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Affiliation(s)
- Xiao-Hong Zhu
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, School of Medicine, Minneapolis, MN, USA.
| | - Wei Chen
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, School of Medicine, Minneapolis, MN, USA
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6
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Wiesner HM, Balla DZ, Shajan G, Scheffler K, Uğurbil K, Chen W, Uludağ K, Pohmann R. (17)O relaxation times in the rat brain at 16.4 tesla. Magn Reson Med 2015; 75:1886-93. [PMID: 26098931 DOI: 10.1002/mrm.25814] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 04/24/2015] [Accepted: 05/21/2015] [Indexed: 12/20/2022]
Abstract
PURPOSE Measurement of the cerebral metabolic rate of oxygen (CMRO2 ) by means of direct imaging of the (17) O signal can be a valuable tool in neuroscientific research. However, knowledge of the longitudinal and transverse relaxation times of different brain tissue types is required, which is difficult to obtain because of the low sensitivity of natural abundance H2 (17) O measurements. METHODS Using the improved sensitivity at a field strength of 16.4 Tesla, relaxation time measurements in the rat brain were performed in vivo and postmortem with relatively high spatial resolutions, using a chemical shift imaging sequence. RESULTS In vivo relaxation times of rat brain were found to be T1 = 6.84 ± 0.67 ms and T2 * = 1.77 ± 0.04 ms. Postmortem H2 (17) O relaxometry at enriched concentrations after inhalation of (17) O2 showed similar T2 * values for gray matter (1.87 ± 0.04 ms) and white matter, significantly longer than muscle (1.27 ± 0.05 ms) and shorter than cerebrospinal fluid (2.30 ± 0.16 ms). CONCLUSION Relaxation times of brain H2 (17) O were measured for the first time in vivo in different types of tissues with high spatial resolution. Because the relaxation times of H2 (17) O are expected to be independent of field strength, our results should help in optimizing the acquisition parameters for experiments also at other MRI field strengths.
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Affiliation(s)
- Hannes M Wiesner
- High-Field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany.,Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - Dávid Z Balla
- High-Field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - G Shajan
- High-Field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Klaus Scheffler
- High-Field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany.,Department of Biomedical Magnetic Resonance, University of Tübingen, Tübingen, Germany
| | - Kâmil Uğurbil
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - Wei Chen
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - Kâmil Uludağ
- Maastricht Brain Imaging Center (M-BIC), Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Rolf Pohmann
- High-Field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
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7
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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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8
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Liss P, Cox EF, Eckerbom P, Francis ST. Imaging of intrarenal haemodynamics and oxygen metabolism. Clin Exp Pharmacol Physiol 2013; 40:158-67. [PMID: 23252679 DOI: 10.1111/1440-1681.12042] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 12/07/2012] [Accepted: 12/12/2012] [Indexed: 01/07/2023]
Abstract
The interruption of blood flow results in impaired oxygenation and metabolism. This can lead to electrophysiological changes, functional impairment and symptoms in quick succession. Quantitative measures of organ perfusion, perfusion reserve and tissue oxygenation are crucial to assess normal tissue metabolism and function. Magnetic resonance imaging (MRI) provides a number of quantitative methods to assess physiology in the kidney. Blood oxygenation level-dependent (BOLD) MRI provides a method for the assessment of oxygenation. Blood flow to the kidney can be assessed using phase contrast MRI. Dynamic contrast-enhanced MRI and arterial spin labelling (ASL) provide methods to assess tissue perfusion, ASL using the magnetization of endogenous water protons and thus providing a non-invasive method to assess perfusion. The application of diffusion-weighted MRI allows molecular motion in the kidney to be measured. Novel techniques can also be used to assess oxygenation in the renal arteries and veins and, combined with flow measures, provide an estimation of oxygen metabolism. Magnetic resonance imaging provides a synergy of non-invasive techniques to study renal function and the demand for these techniques is likely to be driven by the incentive to avoid the use of contrast media, to avoid radiation and to avoid complications with intervention procedures.
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Affiliation(s)
- Per Liss
- Department of Radiology, Center for Medical Imaging, Uppsala University Hospital, Uppsala University, Uppsala, Sweden
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9
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Chinta LV, Lindvere L, Dorr A, Sahota B, Sled JG, Stefanovic B. Quantitative estimates of stimulation-induced perfusion response using two-photon fluorescence microscopy of cortical microvascular networks. Neuroimage 2012; 61:517-24. [PMID: 22521258 DOI: 10.1016/j.neuroimage.2012.04.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 03/30/2012] [Accepted: 04/03/2012] [Indexed: 01/29/2023] Open
Abstract
Functional hyperemia, or the increase in focal perfusion elicited by neuronal activation, is one of the primary functions of the neurovascular unit and a hallmark of healthy brain functioning. While much is known about the hemodynamics on the millimeter to tenths of millimeter-scale accessible by MRI, there is a paucity of quantitative data on the micrometer-scale changes in perfusion in response to functional stimulation. We present a novel methodology for quantification of perfusion and intravascular flow across the 3D microvascular network in the rat somatosensory cortex using two-photon fluorescence microscopy (2PFM). For approximately 96% of responding microvessels in the forelimb representation of the primary somatosensory cortex, brief (~2s) forepaw stimulation resulted in an increase of perfusion 20±4% (mean±sem). The perfusion levels associated with the remaining 4% of the responding microvessels decreased 10±9% upon stimulation. Vessels irrigating regions of lower vascular density were found to exhibit higher flow (p<0.02), supporting the notion that local vascular morphology and hemodynamics reflect the metabolic needs of the surrounding parenchyma. High dispersion (~77%) in perfusion levels suggests high spatial variation in tissue susceptibility to hypoxia. The current methodology enables quantification of absolute perfusion associated with individual vessels of the cortical microvascular bed and its changes in response to functional stimulation and thereby provides an important tool for studying the cellular mechanisms of functional hyperemia, the spatial specificity of perfusion response to functional stimulation, and, broadly, the micrometer-scale relationship between vascular morphology and function in health and disease.
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Affiliation(s)
- Lakshminarayan V Chinta
- Imaging Research, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON, Canada M4N 3M5
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10
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An H, Liu Q, Eldeniz C, Lin W. Absolute oxygenation metabolism measurements using magnetic resonance imaging. Open Neuroimag J 2011; 5:120-35. [PMID: 22276084 PMCID: PMC3256581 DOI: 10.2174/1874440001105010120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2011] [Revised: 02/02/2011] [Accepted: 03/03/2011] [Indexed: 11/29/2022] Open
Abstract
Cerebral oxygen metabolism plays a critical role in maintaining normal function of the brain. It is the primary energy source to sustain neuronal functions. Abnormalities in oxygen metabolism occur in various neuro-pathologic conditions such as ischemic stroke, cerebral trauma, cancer, Alzheimer’s disease and shock. Therefore, the ability to quantitatively measure tissue oxygenation and oxygen metabolism is essential to the understanding of pathophysiology and treatment of various diseases. The focus of this review is to provide an introduction of various blood oxygenation level dependent (BOLD) contrast methods for absolute measurements of tissue oxygenation, including both magnitude and phase image based approaches. The advantages and disadvantages of each method are discussed.
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Affiliation(s)
- Hongyu An
- Department of Radiology and Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, USA
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11
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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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12
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Vazquez AL, Masamoto K, Fukuda M, Kim SG. Cerebral oxygen delivery and consumption during evoked neural activity. FRONTIERS IN NEUROENERGETICS 2010; 2:11. [PMID: 20616881 PMCID: PMC2899518 DOI: 10.3389/fnene.2010.00011] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Accepted: 05/26/2010] [Indexed: 11/13/2022]
Abstract
Increases in neural activity evoke increases in the delivery and consumption of oxygen. Beyond observations of cerebral tissue and blood oxygen, the role and properties of cerebral oxygen delivery and consumption during changes in brain function are not well understood. This work overviews the current knowledge of functional oxygen delivery and consumption and introduces recent and preliminary findings to explore the mechanisms by which oxygen is delivered to tissue as well as the temporal dynamics of oxygen metabolism. Vascular oxygen tension measurements have shown that a relatively large amount of oxygen exits pial arterioles prior to capillaries. Additionally, increases in cerebral blood flow (CBF) induced by evoked neural activation are accompanied by arterial vasodilation and also by increases in arteriolar oxygenation. This increase contributes not only to the down-stream delivery of oxygen to tissue, but also to delivery of additional oxygen to extra-vascular spaces surrounding the arterioles. On the other hand, the changes in tissue oxygen tension due to functional increases in oxygen consumption have been investigated using a method to suppress the evoked CBF response. The functional decreases in tissue oxygen tension induced by increases in oxygen consumption are slow to evoked changes in CBF under control conditions. Preliminary findings obtained using flavoprotein autofluorescence imaging suggest cellular oxidative metabolism changes at a faster rate than the average changes in tissue oxygen. These issues are important in the determination of the dynamic changes in tissue oxygen metabolism from hemoglobin-based imaging techniques such as blood oxygenation-level dependent functional magnetic resonance imaging (fMRI).
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Affiliation(s)
- Alberto L Vazquez
- Department of Radiology, University of Pittsburgh Pittsburgh, PA, USA
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13
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Feasibility of mapping the tissue mass corrected bioscale of cerebral metabolic rate of oxygen consumption using 17-oxygen and 23-sodium MR imaging in a human brain at 9.4T. Neuroimage 2010. [DOI: 10.1016/j.neuroimage.2010.02.056 (epub feb 24, 2010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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14
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Atkinson IC, Thulborn KR. Feasibility of mapping the tissue mass corrected bioscale of cerebral metabolic rate of oxygen consumption using 17-oxygen and 23-sodium MR imaging in a human brain at 9.4T. Neuroimage 2010; 51:723-33. [DOI: 10.1016/j.neuroimage.2010.02.056] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Revised: 01/14/2010] [Accepted: 02/17/2010] [Indexed: 11/27/2022] Open
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15
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Gerothanassis IP. Oxygen-17 NMR spectroscopy: basic principles and applications (part I). PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2010; 56:95-197. [PMID: 20633350 DOI: 10.1016/j.pnmrs.2009.09.002] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Accepted: 09/24/2009] [Indexed: 05/29/2023]
Affiliation(s)
- Ioannis P Gerothanassis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina GR-451 10, Greece.
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16
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Abstract
In recent years, there have been unprecedented methodological advances in the dynamic imaging of brain activities. Electrophysiological, optical, and magnetic resonance methods now allow mapping of functional activation (or deactivation) by measurement of neural activity (e.g., membrane potential, ion flux, neurotransmitter flux), energy metabolism (e.g., glucose consumption, oxygen consumption, creatine kinase flux), and functional hyperemia (e.g., blood oxygenation, blood flow, blood volume). Properties of the glutamatergic synapse are used to model activities at the nerve terminal and their associated changes in energy demand and blood flow. This approach reveals that each method measures different tissue- and/or cell-specific components with characteristic spatiotemporal resolution. While advantages and disadvantages of different methods are apparent and often used to supersede one another in terms of specificity and/or sensitivity, no particular technique is the optimal dynamic brain imaging method because each method is unique in some respect. Since the demand for energy substrates is a fundamental requirement for function, energy-based methods may allow quantitative dynamic imaging in vivo. However, there are exclusive neurobiological insights gained by combining some of these different dynamic imaging techniques.
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Affiliation(s)
- Fahmeed Hyder
- Departments of Diagnostic Radiology and Biomedical Engineering, Program in Quantitative Neuroscience with Magnetic Resonance, Magnetic Resonance Research Center, Yale University, New Haven, CT, USA
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17
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Zhu XH, Du F, Zhang N, Zhang Y, Lei H, Zhang X, Qiao H, Ugurbil K, Chen W. Advanced In Vivo Heteronuclear MRS Approaches for Studying Brain Bioenergetics Driven by Mitochondria. Methods Mol Biol 2009; 489:317-57. [PMID: 18839099 PMCID: PMC5348251 DOI: 10.1007/978-1-59745-543-5_15] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The greatest merit of in vivo magnetic resonance spectroscopy (MRS) methodology used in biomedical research is its ability for noninvasively measuring a variety of metabolites inside a living organ. It, therefore, provides an invaluable tool for determining metabolites, chemical reaction rates and bioenergetics, as well as their dynamic changes in the human and animal. The capability of in vivo MRS is further enhanced at higher magnetic fields because of significant gain in detection sensitivity and improvement in the spectral resolution. Recent progress of in vivo MRS technology has further demonstrated its great potential in many biomedical research areas, particularly in brain research. Here, we provide a review of new developments for in vivo heteronuclear 31P and 17O MRS approaches and their applications in determining the cerebral metabolic rates of oxygen and ATP inside the mitochondria, in both animal and human brains.
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Affiliation(s)
- Xiao-Hong Zhu
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, School of Medicine, Minneapolis, MN, USA
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18
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Lai N, Saidel GM, Grassi B, Gladden LB, Cabrera ME. Model of oxygen transport and metabolism predicts effect of hyperoxia on canine muscle oxygen uptake dynamics. J Appl Physiol (1985) 2007; 103:1366-78. [PMID: 17600157 DOI: 10.1152/japplphysiol.00489.2007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Previous studies have shown that increased oxygen delivery, via increased convection or arterial oxygen content, does not speed the dynamics of oxygen uptake, V̇o2m, in dog muscle electrically stimulated at a submaximal metabolic rate. However, the dynamics of transport and metabolic processes that occur within working muscle in situ is typically unavailable in this experimental setting. To investigate factors affecting V̇o2m dynamics at contraction onset, we combined dynamic experimental data across working muscle with a mechanistic model of oxygen transport and metabolism in muscle. The model is based on dynamic mass balances for O2, ATP, and PCr. Model equations account for changes in cellular ATPase, oxidative phosphorylation, and creatine kinase fluxes in skeletal muscle during exercise, and cellular respiration depends on [ADP] and [O2]. Model simulations were conducted at different levels of arterial oxygen content and blood flow to quantify the effects of convection and diffusion of oxygen on the regulation of cellular respiration during step transitions from rest to isometric contraction in dog gastrocnemius muscle. Simulations of arteriovenous O2 differences and V̇o2m dynamics were successfully compared with experimental data (Grassi B, Gladden LB, Samaja M, Stary CM, Hogan MC. J Appl Physiol 85: 1394–1403, 1998; and Grassi B, Gladden LB, Stary CM, Wagner PD, Hogan MC. J Appl Physiol 85: 1404–1412, 1998), thus demonstrating the validity of the model, as well as its predictive capability. The main findings of this study are: 1) the estimated dynamic response of oxygen utilization at contraction onset in muscle is faster than that of oxygen uptake; and 2) hyperoxia does not accelerate the dynamics of diffusion and consequently muscle oxygen uptake at contraction onset due to the hyperoxia-induced increase in oxygen stores. These in silico derived results cannot be obtained from experimental observations alone.
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Affiliation(s)
- Nicola Lai
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
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19
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Abstract
There is a wide range of functional magnetic resonance imaging (fMRI) study designs available for the neuroscientist who wants to investigate cognition. In this manuscript we review some aspects of fMRI study design, including cognitive comparison strategies (factorial, parametric designs), and stimulus presentation possibilities (block, event-related, rapid event-related, mixed, and self-driven experiment designs) along with technical aspects, such as limitations of signal to noise ratio, spatial, and temporal resolution. We also discuss methods to deal with cases where scanning parameters become the limiting factor (parallel acquisitions, variable jittered designs, scanner acoustic noise strategies).
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Affiliation(s)
- Edson Amaro
- Neuroimaging Research Group, Institute of Psychiatry, King's College, University College, London, UK.
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20
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Fiat D, Hankiewicz J, Liu S, Trbovic S, Brint S. 17O magnetic resonance imaging of the human brain. Neurol Res 2005; 26:803-8. [PMID: 15727263 DOI: 10.1179/016164104x5156] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Here we show the first example of in vivo oxygen-17 (17O) magnetic resonance imaging of the human in natural abundance. Two-dimensional fast multi-planar gradient recalled 90 deg echo (FMPGR/90) pulse sequence and three-dimensional projection reconstruction pulse sequence methods were used.
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Affiliation(s)
- Daniel Fiat
- Magnetic Resonance Imaging Laboratory, Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL 60612-7342, USA.
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Zhu XH, Zhang N, Zhang Y, Zhang X, Ugurbil K, Chen W. In vivo 17O NMR approaches for brain study at high field. NMR IN BIOMEDICINE 2005; 18:83-103. [PMID: 15770611 DOI: 10.1002/nbm.930] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
17O is the only stable oxygen isotope that can be detected by NMR. The quadrupolar moment of 17O spin (I = 5/2) can interact with local electric field gradients, resulting in extremely short T1 and T2 relaxation times which are in the range of several milliseconds. One unique NMR property of 17O spin is the independence of 17O relaxation times on the magnetic field strength, and this makes it possible to achieve a large sensitivity gain for in vivo 17O NMR applications at high fields. In vivo 17O NMR has two major applications for studying brain function and cerebral bioenergetics. The first application is to measure the cerebral blood flow (CBF) through monitoring the washout of inert H2 17O tracer in the brain tissue following an intravascular bolus injection of the 17O-labeled water. The second application, perhaps the most important one, is to determine the cerebral metabolic rate of oxygen utilization (CMRO2) through monitoring the dynamic changes of metabolically generated H2 17O from inhaled 17O-labeled oxygen gas in the brain tissue. One great merit of in vivo 17O NMR for the determination of CMRO2 is that only the metabolic H2 17O is detectable. This merit dramatically simplifies both CMRO2 measurement and quantification compared to other established methods. There are two major NMR approaches for monitoring H2 17O in vivo, namely direct approach by using 17O NMR detection (referred as direct in vivo 17O NMR approach) and indirect approach by using 1H NMR detection for measuring the changes in T2- or T1rho-weighted proton NMR signals caused by the 17O-1H scalar coupling and proton chemical exchange (referred as indirect in vivo 17O NMR approach). Both approaches are suitable for CBF measurements. However, recent studies indicated that the direct in vivo 17O NMR approach at high/ultrahigh fields appears to offer significant advantages for quantifying and imaging CMRO2. New developments have further demonstrated the feasibility for establishing a completely noninvasive in vivo 17O NMR approach for imaging CMRO2 in a rat brain during a brief 17O2 inhalation. This approach should be promising for studying the central role of oxidative metabolism in brain function and neurological diseases. Finally, the similar approach could potentially be applied to image CMRO2 noninvasively in human brain.
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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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Swartz HM, Dunn J. The Difficulties in Comparing In Vivo Oxygen Measurements. OXYGEN TRANSPORT TO TISSUE XXVI 2005; 566:295-301. [PMID: 16594165 DOI: 10.1007/0-387-26206-7_39] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
There has been rapid development of effective new tools that provide information on oxygenation in vivo and an increased recognition of how valuable such information can be. Consequently, there also has been considerable interest in comparing and evaluating the accuracy and usefulness of the different types of measurements. The various types of measurements usually do not measure the same thing. They may measure PO2 or [O2] or something less directly related, such as hemoglobin saturation. They may make measurements in different compartments (e.g. intracellular, extracellular, vascular) in the volume that they sample, the time span over which they average, the local perturbation that they may cause, etc. They also differ in their sensitivity, accuracy, ability to measure repetitively. However, these potentially confounding and confusing differences can be made into an outstanding virtue, if their nature is considered carefully. Then a proper model can relate them to each other. The ability to relate the various measurements to each other can be a powerful tool to test the validity of models that attempt to explain fully the distribution of oxygen in real systems and the factors that affect this. We then could have a major advancement in our understanding of oxygen transport in tissues, with an ability to determine accurately the effects of physiological and pathophysiological perturbations on oxygenation at all levels of cells and tissues in vivo.
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Zhu XH, Zhang Y, Tian RX, Lei H, Zhang N, Zhang X, Merkle H, Ugurbil K, Chen W. Development of (17)O NMR approach for fast imaging of cerebral metabolic rate of oxygen in rat brain at high field. Proc Natl Acad Sci U S A 2002; 99:13194-9. [PMID: 12242341 PMCID: PMC130609 DOI: 10.1073/pnas.202471399] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2002] [Accepted: 08/06/2002] [Indexed: 11/18/2022] Open
Abstract
A comprehensive technique was developed for using three-dimensional (17)O magnetic resonance spectroscopic imaging at 9.4T for rapidly imaging the cerebral metabolic rate of oxygen consumption (CMRO(2)) in the rat brain during a two-min inhalation of (17)O(2). The CMRO(2) value (2.19 +/- 0.14 micromol/g/min, n = 7) was determined in the rat anesthetized with alpha-chloralose by independent and concurrent (17)O NMR measurements of cerebral H(2)17O content, arterial input function, and cerebral perfusion. CMRO(2) values obtained were consistent with the literature results for similar conditions. Our results reveal that, because of its superior sensitivity at ultra-high fields, the (17)O magnetic resonance spectroscopic imaging approach is capable of detecting small dynamic changes of metabolic H(2)17O during a short inhalation of (17)O(2) gas, and ultimately, for imaging CMRO(2) in the small rat brain. This study provides a crucial step toward the goal of developing a robust and noninvasive (17)O NMR approach for imaging CMRO(2) in animal and human brains that can be used for studying the central role of oxidative metabolism in brain function under normal and diseased conditions, as well as for understanding the mechanisms underlying functional MRI.
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Affiliation(s)
- Xiao-Hong Zhu
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, 2021 6th Street SE, Minneapolis, MN 55455, USA
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Zhu XH, Merkle H, Kwag JH, Ugurbil K, Chen W. 17O relaxation time and NMR sensitivity of cerebral water and their field dependence. Magn Reson Med 2001; 45:543-9. [PMID: 11283979 DOI: 10.1002/mrm.1073] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
17O spin relaxation times and sensitivity of detection were measured for natural abundance H(2)(17)O in the rat brain at 4.7 and 9.4 Tesla. The relaxation times were found to be magnetic field independent (T(2) = 3.03 +/- 0.08 ms, T(*)(2) = 1.79 +/- 0.04 ms, and T(1) = 4.47 +/- 0.14 ms at 4.7T (N = 5); T(2) = 3.03 +/- 0.09 ms, T(*)(2) = 1.80 +/- 0.06 ms, and T(1) = 4.84 +/- 0.18 ms at 9.4T (N = 5)), consistent with the concept that the dominant relaxation mechanism is the quadrupolar interaction for this nucleus. The (17)O NMR sensitivity was more than fourfold higher at 9.4T than at 4.7T, for both the rat brain and a sodium chloride solution. With this sensitivity gain, it was possible to obtain localized (17)O spectra with an excellent signal-to-noise ratio (SNR) within 15 s of data acquisition despite the relatively low gyromagnetic ratio of this nucleus. Such a 15-s 2D (17)O-MRS imaging data set obtained for natural abundance H(2)(17)O in the rat brain yielded an SNR greater than 40:1 for a approximately 16 microl voxel. This approach was employed to measure cerebral blood flow using a bolus injection of H(2)(17)O via one internal carotid artery. These results demonstrate the ability of (17)O-MRS imaging to reliably map the H(2)(17)O dynamics in the brain tissue, and its potential for determining tissue blood flow and oxygen consumption rate changes in vivo. Magn Reson Med 45:543-549, 2001.
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Affiliation(s)
- X H Zhu
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota School of Medicine, Minneapolis, Minnesota 55455, USA
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Abstract
This work presents a novel approach for quantifying low concentrations of H(2)(17)O in vivo and explores its utility for assessing cerebral ischemia. Oxygen-17 enriched water acts as a T(2) shortening contrast agent whose effect can be suppressed by decoupling at the (17)O frequency during TE interval in a spin-echo MR image. Serial T(2)-weighted echo planar images were acquired in phantoms and rat brain with decoupler power alternated every eight images. The resulting periodic signal change (proportional to H(2)(17)O concentration) was detected by cross-correlating the square-wave decoupler power timecourse with the signal intensity in each voxel. Natural abundance (0.037 atom%) images of H(2)(17)O in rat brain were generated. The transverse relaxivity of H(2)(17)O in brain was estimated, R(2) = 2.4+/-0.5 s(-1)(atom%)(-1). After bolus injection of 1 ml of 10 atom% H(2)(17)O, brain H(2)(17)O concentration was estimated at 0.06+/-0.01 atom%. In the rat focal ischemia model, (17)O cross-correlation maps compared well with diffusion and Gd-DTPA perfusion images to indicate infarct location. Magn Reson Med 43:876-883, 2000.
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Affiliation(s)
- A J de Crespigny
- Lucas Center, Department of Radiology, Stanford University, California, USA.
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Muizelaar JP, Fatouros PP, Schröder ML. A new method for quantitative regional cerebral blood volume measurements using computed tomography. Stroke 1997; 28:1998-2005. [PMID: 9341710 DOI: 10.1161/01.str.28.10.1998] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND AND PURPOSE Knowledge of cerebral blood volume (CBV) is invaluable in identifying the primary cause of brain swelling in patients with stroke or severe head injury, and it might also help in clinical decision making in patients thought to have hemodynamic transient ischemic attacks (TIAs). This investigation is concerned with the development and clinical application of a new method for quantitative regional CBV measurements. METHODS The technique is based on consecutive measurements of cerebral blood flow (CBF) by xenon/CT and tissue mean transit time (MTT) by dynamic CT after a rapid iodinated contrast bolus injection. CBV maps are produced by multiplication of the CBF and MTT maps in accordance with the Central Volume Principle: CBV = CBF x MTT. The method is rapid and easily implemented on CT scanners with the xenon/CBF capability. It yields CBV values expressed in milliliters of blood per 100 grams of tissue. RESULTS The method was validated under controlled physiological conditions causing changes that were determined both with our technique and from pressure-volume index (PVI) measurements. The two independent estimates of CBV changes were in agreement within 15%. CBV measurements using this method were carried out in normal volunteers to establish baseline values and to compare with values using the ratio-of-areas method for calculating both CBF and CBV from the dynamic study alone. Average CBV was 5.3 mL/100 g. The method was also applied in 71 patients with severe head injuries and in 1 patient with hemodynamic TIAs. CONCLUSIONS The primary conclusions from this study were (1) the proposed method for measuring CBV accurately determines changes in CBV; (2) the MTT x CBF determinations are in agreement with the ratio-of-areas method for CBV measurements in normal volunteers and are consistent with other methods reported in the literature; (3) MTTs are significantly prolonged early after severe head injury, which when combined with the finding of decreased CBF and increased arteriovenous difference of oxygen indicates increased cerebrovascular resistance due to narrowing of the microcirculation consistent with the presence of early ischemia; and (4) CBV in the patient with TIAs was increased in the hemisphere with the occluded internal carotid artery, indicating compensatory vasodilation and probable hemodynamic cause.
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Affiliation(s)
- J P Muizelaar
- Department of Neurological Surgery, University of California, Davis, Sacramento 95817, USA
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Filgueiras CL, Winsborrow B, Ye J, Scott J, Aronov A, Kozlowski P, Shabnavard L, Summers R, Saunders JK, Deslauriers R. A 31p-magnetic resonance study of antegrade and retrograde cerebral perfusion during aortic arch surgery in pigs. J Thorac Cardiovasc Surg 1995; 110:55-62. [PMID: 7609569 DOI: 10.1016/s0022-5223(05)80009-1] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
To evaluate the effect of hypothermic circulatory arrest on brain metabolism, we used 31P-magnetic resonance spectroscopy to monitor brain metabolites in pigs during 2 hours of ischemia and 1 hour of reperfusion. Twenty-eight pigs were divided into five groups. Anesthesia (n = 5) and hypothermic cardiopulmonary bypass groups (n = 5) served as controls. In the circulatory arrest (n = 6), antegrade perfusion (n = 6), and retrograde (n = 6) brain perfusion groups, the bypass flow rate was 60 to 100 ml.kg-1.min-1. In the antegrade group, the brain was perfused via the carotid arteries at a blood flow rate of 180 to 200 ml.min-1 during circulatory arrest at 15 degrees C. In the retrograde group, the brain was perfused through the superior vena cava at a flow rate of 300 to 500 ml.min-1 during circulatory arrest at 15 degrees C. The intracellular pH was 7.1 +/- 0.1 and 7.3 +/- 0.1 in the anesthesia and hypothermic cardiopulmonary bypass groups, respectively. In the circulatory arrest group, the intracellular pH decreased to 6.2 +/- 0.1 and did not recover to its initial value (7.0 +/- 0.1) during reperfusion (p < 0.05 compared with the value obtained from the control groups at the corresponding time). Inorganic phosphate did not return to its initial level during reperfusion. In three animals in this group, levels of high-energy phosphates, adenosine triphosphate and phosphocreatine, recovered partially but did not reach the levels observed before arrest. In the group receiving antegrade perfusion, cerebral metabolites and intracellular pH were unchanged throughout the protocol. During circulatory arrest in the retrograde perfusion group the intracellular pH decreased to 6.4 +/- 0.1 and recovered fully during reperfusion (7.1 +/- 0.1). High-energy phosphates also returned to their initial levels during reperfusion. These studies show that deep hypothermic circulatory arrest with antegrade brain perfusion provides the best brain protection of the options investigated.
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Affiliation(s)
- C L Filgueiras
- Institute for Biodiagnostics, National Research Coucil, Canada, Winnipeg, Manitoba
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