Doubling EPI resolution by acquiring two k-space lines per readout gradient reversal using TRAIL
De Vita E, Ordidge R, Priest A
University College London, UCL Hospitals NHS Trust
The resolution of single-shot EPI is restricted because of limits on the readout length due to T2* decay and distortion. A new method is presented which doubles the resolution of EPI in the phase-encode direction without increasing the readout length, based on a modification of the recently published Two Reduced Acquisitions InterLeaved (TRAIL) method (Priest et al, MRM 2004). Distortion is reduced by a factor of two. The correction of N/4 Nyquist ghosts in the images is also addressed. The new method is complementary to, and could in principle be combined with, existing approaches such as parallel imaging.