Open AccessQuantitative Comparison of Functional Contrast from BOLD-Weighted Spin-Echo and Gradient-Echo Echoplanar Imaging at 1.5 Tesla and H215O PET in the Whole Brain
Author(s) -
Mark J. Lowe,
Joseph T. Lurito,
Vincent P. Mathews,
Micheal D. Phillips,
Gary D. Hutchins
Publication year - 2000
Publication title -
journal of cerebral blood flow and metabolism
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.167
H-Index - 193
eISSN - 1559-7016
pISSN - 0271-678X
DOI - 10.1097/00004647-200009000-00008
Subject(s) - cerebral blood flow , cortex (anatomy) , nuclear medicine , thalamus , gyrus , magnetic resonance imaging , cerebral cortex , motor cortex , functional magnetic resonance imaging , primary motor cortex , nuclear magnetic resonance , positron emission tomography , medicine , neuroscience , psychology , physics , radiology , stimulation
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.