Fast Imaging Technique for fMRI: Consecutive Multishot Echo Planar Imaging Accelerated with GRAPPA Technique

Figure 1

Simplified pulse sequence diagram. (a) The definition of a segment in multishot EPI, which consists of a fat-saturating RF pulse, a slice-selective RF pulse, navigators, and a data acquisition. Timing diagrams of (b) cmsEPI for 6 segments and (c) accelerated cmsEPI with reduction factor of for 6 segments. For the reference data of , all six segments need to be acquired but in two sets: one includes 1st, 3rd, and 5th segments and the other 2nd, 4th, and 6th segments as described in (d). Fat Sat.: fat saturation; FA: flip angle; Nav.: navigation echo; Seg.: segment; TR: repetition time or time for acquisition of one slice.