Improved Region-Optimized Virtual Coils for Cartesian Acquisition Geometries

Motivation: ROVir (Region-Optimized Virtual coils) is a technique that constructs MRI virtual coils in a way that seeks to simultaneously maximize the amount of information captured by the smallest number of virtual coils (coil compression/dimensionality reduction) while also suppressing signal from undesired spatial regions (avoiding aliasing/leakage artifacts). Although ROVir generally performs well, its performance can sometimes be limited by coil geometry. Goal(s): To improve the performance of ROVir. Approach: We exploit the structure of Cartesian imaging, calculating distinct ROVir weights for each position along the fully-sampled readout. Results: The proposed approach enables substantially better dimensionality reduction and signal suppression performance. Impact: The proposed approach provides substantially better signal suppression and coil compression for Cartesian acquisitions, alleviating burdens on data acquisition (reducing the need for sequence-based signal suppression and enabling reduced-FOV imaging) and reducing the computational complexity of image reconstruction.