Elimination of Artefacts in Fast Spin Echo Imaging Caused by T2 Decay During the Echo Train by Combining Novel K-space Ordering (Feathering) and Parallel Imaging
Carmichael D, Thomas D, Ordidge R
Insititute of Neurology, University College London
In multi-echo imaging sequences like the fast spin echo (FSE), the point spread function (PSF) in the phase encoding direction is significantly degraded. This is due to discontinuities in adjacent k-space data obtained at different echo times caused by T2 decay. To improve the PSF, data are acquired alternately at different echo times (called feathering) in the regions of discontinuity. Using GRAPPA with feathered array coil data it is possible to reconstruct data over the region of the discontinuity from both echo times. This is used to dramatically improve the PSF, eliminating artefacts in both simulations and FSE images.