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Comparison of diffusion‐weighted high‐resolution CBF and spin‐echo BOLD fMRI at 9.4 T
Author(s) -
Lee SangPil,
Silva Afonso C.,
Kim SeongGi
Publication year - 2002
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/mrm.10117
Subject(s) - cerebral blood flow , nuclear magnetic resonance , functional magnetic resonance imaging , neuroscience , communication noise , blood oxygen level dependent , physics , psychology , medicine , cardiology , linguistics , philosophy
The quantification of blood oxygenation‐level dependent (BOLD) functional MRI (fMRI) signals is closely related to cerebral blood flow (CBF) change; therefore, understanding the exact relationship between BOLD and CBF changes on a pixel‐by‐pixel basis is fundamental. In this study, quantitative CBF changes induced by neural activity were used to quantify BOLD signal changes during somatosensory stimulation in α‐chloralose‐anesthetized rats. To examine the influence of fast‐moving vascular spins in quantifying CBF, bipolar gradients were employed. Our data show no significant difference in relative CBF changes obtained with and without bipolar gradients. To compare BOLD and CBF signal changes induced by neural stimulation, a spin‐echo (SE) sequence with long SE time of 40 ms at 9.4 T was used in conjunction with an arterial spin labeling technique. SE BOLD changes were quantitatively correlated to CBF changes on a pixel‐by‐pixel and animal‐by‐animal basis. Thus, SE BOLD‐based fMRI at high magnetic fields allows a quantitative comparison of functional brain activities across brain regions and subjects. Magn Reson Med 47:736–741, 2002. © 2002 Wiley‐Liss, Inc.