1Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom, 2Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom
DTI sequences based on EPI allow rapid acquisitions of image
slices by traversing k-space lines in opposite directions following a single RF
excitation. During long acquisition trains, phase errors caused by field
inhomogeneity can lead to distortion. Acquiring slices in multiple shots can
mitigate this effect. Motion between shots, however, results in ghosting that
cannot be corrected. We show that slice-wise phase correction by entropy
minimisation reduces ghosting compared to the manufacturer software (ParaVision
4.0, Bruker). Second, we propose an algorithm to automatically detect and
reject slices with residual motion-induced ghosting, and validate it in a large
cohort of mice.
