Functional MRI using interleaved EPI

: One of main purposes of functional MRI is to identify functional map on human brain. We considered spatial resolution was a important factor and investigated influences of it on signal changes and activated region size. Functional images were acquired with Echo-Planar imaging (EPI) and interleaved EPI (IEPI). IEPI is superior in spatial resolution but inferior in signal to noise ratio (SNR) to EPI. As a result of Student's t-test analysis, activated region sizes of IEPI reduced to less than half those of EPI while IEPI had larger signal increase than EPI. We confirmed that the reduction was caused by low SNR and our estimation analysis could prevent it.