[Brain functional MRI of the visual cortex with echo planar imaging].
Brain functional MR imaging (fMRI) is a non invasive imaging method for detecting neural activity. We performed functional MRI of the visual cortex with gradient-echo echo planar imaging (GE-EPI) and spin-echo EPI (SE-EPI) using 1.5T MRI system. Visual stimuli was performed with a checkerboard patterns. Magnitude and temporal phase of correlation between each pixel's time-course and sine functions at the frequency of the stimulus was calculated. In all subjects, the activation area in visual cortex obtained from SE-EPI was smaller than that from GE-EPI. Temporal phase delay images from both GE-EPI and SE-EPI showed signal spread from the primary visual cortex to peripheral supplementary areas. Temporal phase analysis is important to discriminate the source of the hemodynamic response to neural activation in fMRI.
Yamada
H
H
Department of Radiology, Fukui Medical School.
D017352:Echo-Planar Imaging / Q000379:methods*; D006801:Humans; D010775:Photic Stimulation; D014793:Visual Cortex / Q000033:anatomy & histology / Q000502:physiology*