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Early changes in water diffusion, perfusion, T 1 , and T 2 during focal cerebral ischemia in the rat studied at 8.5 T
Author(s) -
Calamante Fernando,
Lythgoe Mark F.,
Pell Gaby S.,
Thomas David L.,
King Martin D.,
Busza Albert L.,
Sotak Christopher H.,
Williams Stephen R.,
Ordidge Roger J.,
Gadian David G.
Publication year - 1999
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/(sici)1522-2594(199903)41:3<479::aid-mrm9>3.0.co;2-2
Subject(s) - perfusion , ischemia , magnetic resonance imaging , diffusion , oxygenation , cerebral blood flow , nuclear magnetic resonance , occlusion , blood flow , medicine , perfusion scanning , arterial spin labeling , cardiology , chemistry , radiology , physics , thermodynamics
The time evolution of water diffusion, perfusion, T 1 , and T 2 is investigated at high magnetic field (8.5 T) following permanent middle cerebral artery occlusion in the rat. Cerebral blood flow maps were obtained using arterial spin tagging. Although the quantitative perfusion measurements in ischemic tissue still pose difficulties, the combined perfusion and diffusion data nevertheless distinguish between a “moderately affected area,” with reduced perfusion but normal diffusion; and a “severely affected area,” in which both perfusion and diffusion are significantly reduced. Two novel magnetic resonance imaging observations are reported, namely, a decrease in T 2 and an increase in T 1 , both within the first few minutes of ischemia. The rapid initial decrease in T 2 is believed to be associated with an increase in deoxyhemoglobin levels, while the initial increase in T 1 may be related to several factors, such as flow effects, an alteration in tissue oxygenation, and changes in water environment. Magn Reson Med 41:479–485, 1999. © 1999 Wiley‐Liss, Inc.