A Comparison between Low Rank Reduced FOV and Region Optimized Virtual Coils Reconstructions

Motivation: Reduced FOV (rFOV) imaging aims to preserve maximum signal within a region-of-interest (ROI), while minimizing contamination from outside signal and the amplification of noise. Goal(s): To compare the characteristics of two novel phased-array based rFOV techniques that function from different formulations: low-rank rFOV (LR-rFOV) and ROVir. These characteristics are ROI signal preservation, susceptibility to outside leakage, and noise amplification. Approach: Carried out adapted L-factor analysis to evaluate signal preservation and outside signal leakage for in-plane rFOV and through-slice (i.e. SMS). SNR and g-factor were also evaluated. Results: LR-rFOV outperformed ROVir in preserving ROI signal, minimizing outside signal contamination, and had less noise amplification. Impact: LR-rFOV provides better outside signal suppression and better preserves ROI signal than ROVir. This approach enables one to save time at the scanner by only prescribing the FOV over the desired ROI.