A low rank k-space approach to channel-by-channel reduced FOV imaging

Motivation: To introduce a channel-by-channel reduced field-of-view (FOV) method for an arbitrary region of interest (ROI). Goal(s): With Nc channels as input, we output Nc channels, with the signal outside of the target ROI vectorially nulled while preserving the original channel sensitivity profiles and relative phases for each channel. Approach: Using a full-FOV calibration set, we learned the linear operators needed to be applied on local k-space neighbors across all channels in order to vectorially cancel the signal outside of the target-ROI for any channel. Results: We were able to generate reduced FOV images in phantom and in vivo settings. Impact: A reduced FOV method is introduced that determines the linear operators needed to vectorially cancel the signal outside the target ROI. The output is the Nc channels with the region outside of the target ROI cancelled while preserving channel sensitivities.