Improved spatial harmonic selection for SMASH image reconstructions

The fitting of coil sensitivity functions to spatial harmonics is central t o image reconstructions using the simultaneous acquisition of spatial harmo nics (SMASH) technique. It has previously been shown that the selection of the set of spatial harmonics used in a SMASH reconstruction can have a noti ceable effect on the quality of the reconstructed image. However, a mechani sm for automatic selection of the best set of harmonics in any particular s ituation has not been provided. In this work, a modification to the SMASH r econstruction procedure is introduced that allows the use of a weighted ave rage of all possible harmonics in a reconstruction. The new reconstruction procedure is shown to allow automatic selection of the spatial harmonics an d substantially improve SNR for both phantom and in vivo images. (C) 2001 W iley-Liss, Inc.