In:
Journal of Cerebral Blood Flow & Metabolism, SAGE Publications, Vol. 20, No. 9 ( 2000-09), p. 1331-1340
Abstract:
Spin-echo and gradient-echo echoplanar functional magnetic resonance imaging (fMRI) studies at 1.5 Tesla (T) were used to obtain blood oxygenation level-dependent (BOLD) contrast images of the whole brain in seven strongly right-handed women during execution of a complex motor task. Five subjects underwent subsequent H 2 15 O positron emission tomography (PET) studies while performing the same task. Group-averaged results for changes in the MRI relaxation rates R 2 * and R 2 at 1.5T in response to neuronal activation in nine cortical, subcortical, and cerebellar motor regions are reported. Results for each method are grouped according to tissue type—cerebral cortex (precentral gyrus and supplementary motor area), subcortical regions (thalamus and putamen), and cerebellar cortex (superior lobule). The observed changes in R 2 * from activation-induced oxygenation changes were more variable across brain regions with different tissue characteristics than observed changes in R 2 . The ratio of ΔR 2 * to ΔR 2 was 3.3 ± 0.9 for cerebral cortex and 2.0 ± 0.6 for subcortical tissue. ΔR 2 *, ΔR 2 , and relative blood flow changes were ΔR 2 * = −0.201 ± 0.040 s −1 , ΔR 2 = −0.064 ± 0.011 s −1 , and Δf/f = 16.7 ± 0.8% in the cerebral cortex; ΔR 2 * = −0.100 ± 0.026 s −1 , ΔR 2 = −0.049 ± 0.009 s −1 , and Δf/f = 9.4 ± 0.7% in the subcortical regions; and ΔR 2 * = −0.215 ± 0.093 s −1 , ΔR 2 = −0.069 ± 0.012 s −1 , and Δf/f = 16.2 ± 1.2% in the cerebellar cortex.
Type of Medium:
Online Resource
ISSN:
0271-678X
,
1559-7016
DOI:
10.1097/00004647-200009000-00008
Language:
English
Publisher:
SAGE Publications
Publication Date:
2000
detail.hit.zdb_id:
2039456-1
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