Silent Looping Star fMRI with enhanced Encoding and Reconstruction Performance

Motivation: Silent Looping Star fMRI offers unique advantages for neuroscience investigation, but image quality is affected by undersampling artifacts. Goal(s): Here, we describe novel methods for improving the spatiotemporal encoding efficiency of Looping Star and thereby further advance its utility for silent fMRI. Approach: A new Looping Star encoding scheme which adds extra out-of-plane oscillations and thereby improves overall encoding efficiency is introduced and combined with auto-calibrated cgSENSE parallel imaging reconstruction. Results: The sharpest, most intensity uniform images and lowest background noise are demonstrated by the combination of both enhancements while maintaining BOLD sensitivity in a simultaneous, combined visual and auditory fMRI task. Impact: The combination of a new trajectory and auto-calibrated parallel imaging leads to sharper and more uniform silent fMRI images with reduced streaking artifacts as demonstrated visually and on a visual-auditory fMRI task.