| Dynamic imaging of perfusion and oxygenation by functional magnetic resonance imaging. | |
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MedLine Citation:
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PMID: 15625411 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Cerebral blood flow can be measured with magnetic resonance imaging (MRI) by arterial spin labeling techniques, where magnetic labeling of flowing spins in arterial blood water functions as the endogenous tracer upon mixing with the unlabeled stationary spins of tissue water. The consequence is that the apparent longitudinal relaxation time (T1) of tissue water is attenuated. A modified functional MRI scheme for dynamic CBF measurement is proposed that depends on extraction of T1 weighting from the blood oxygenation level-dependent (BOLD) image contrast, because the functional MRI signal also has an intrinsic T1 weighting that can be altered by variations of the excitation flip angle. In the alpha-chloralose-anesthetized rat model at 7T, the authors show that the stimulation-induced BOLD signal change measured with two different flip angles can be combined to obtain a T1-weighted MRI signal, reflecting the magnitude of the CBF change, which can be deconvolved to obtain dynamic changes in CBF. The deconvolution of the T1-weighted MRI signal, which is a necessary step for accurate reflection of the dynamic changes in CBF, was made possible by a transfer function obtained from parallel laser-Doppler flowmetry experiments. For all stimulus durations (ranging from 4 to 32 seconds), the peak CBF response measured by MRI after the deconvolution was reached at 4.5 +/- 1.0 seconds, which is in good agreement with (present and prior) laser-Doppler measurements. Because the low flip angle data can also provide dynamic changes of the conventional BOLD image contrast, this method can be used for simultaneous imaging of CBF and BOLD dynamics. |
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Authors:
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Ikuhiro Kida; Paul K Maciejewski; Fahmeed Hyder |
Publication Detail:
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Type: Journal Article; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism Volume: 24 ISSN: 0271-678X ISO Abbreviation: J. Cereb. Blood Flow Metab. Publication Date: 2004 Dec |
Date Detail:
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Created Date: 2004-12-30 Completed Date: 2005-01-14 Revised Date: 2007-11-14 |
Medline Journal Info:
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Nlm Unique ID: 8112566 Medline TA: J Cereb Blood Flow Metab Country: United States |
Other Details:
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Languages: eng Pagination: 1369-81 Citation Subset: IM |
Affiliation:
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Magnetic Resonance Research Center, Department of Diagnostic Radiology, Yale University, New Haven, Connecticut 06510, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Brain / blood supply, metabolism Cerebrovascular Circulation* Magnetic Resonance Imaging Male Oxygen / blood* Perfusion Rats Rats, Sprague-Dawley Time Factors |
| Grant Support | |
ID/Acronym/Agency:
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DC-03710/DC/NIDCD NIH HHS; MH-67528/MH/NIMH NIH HHS; NS-37203/NS/NINDS NIH HHS; NS-44316/NS/NINDS NIH HHS |
| Chemical | |
Reg. No./Substance:
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7782-44-7/Oxygen |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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