Comparison of BOLD and CBV-weighted fMRI Studies using Multiple-refocused Spin-Echo
Jin T, Kim S
University of Pittsburgh
In fMRI, spin-echo sequences can provide better spatial localization to the brain parenchyma than gradient-echo sequences because the dynamic-averaging effect is more prominent for field inhomogeneities of small scales. In order to investigate the mechanisms of the BOLD and CBV-weighted SE signal change, high resolution multiple-refocused spin-echo (MSE) measurements were conducted at 9.4T, which suppress the dynamic-averaging effect by the additional refocusing pulses. It was suggested that the T2* effect can contribute significantly to the fMRI contrast in a SE-EPI sequence because of the long EPI readout time. This effect was also evaluated and found to be negligible in our results.