1Radiology, University of Wisconsin - Madison, Madison, WI, United States; 2Electrical Engineering, University of Southern California, Los Angeles, CA, United States; 3Mayo Clinic, Rochester, MN, United States
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.