Calibrationless Chemical Shift Encoded Imaging Using a Time-Segmented K-Space Reconstruction

Samir D. Sharma¹, ², Joshua D. Trzasko³, Armando Manduca³

Conventional image-domain-based methods for chemical shift encoding are limited both by their long scan time, which can restrict spatial resolution and/or volume coverage, and their sensitivity to intraecho off-resonance, which can cause geometric distortion. Previous works have proposed either accelerating image-domain-based methods or using a k-space-based formulation to mitigate the effects of intraecho off-resonance. In this work, we develop and demonstrate a framework for accelerated k-space-based chemical shift encoding. We employ a time-segmented approximation of the multispecies MR signal equation and we exploit prior information on intercoil structure and image sparsity to achieve acceleration. We demonstrate accelerated water-fat separation with reduced geometric distortions as compared to a conventional image-domain-based method.