Rapid T1 Relaxation Time Quantification with Enhanced Accuracy Using Simultaneous Acquisition of Phase-Encoding in Inversion-Recovery EPI

Motivation: The inversion-recovery method for T1 mapping typically requires a relatively long acquisition time which can be significantly shortened using EPI techniques. However, substantial geometric distortions in EPI often hinder accurate T1 quantification. Goal(s): We propose a novel IR-EPI scheme that simultaneously acquires EPI data with the reversed phase-encoding direction in a single IR measurement. Approach: Geometric distortions of IR-EPI data were corrected using the blip-up/blip-down approach. Its performance was evaluated in direct comparison to that of original IR-EPI. Results: The proposed scheme enables effective distortion correction for IR-EPI data, enhancing T1 mapping accuracy while providing rapid, whole-cerebrum acquisition at 7T. Impact: The proposed IR-EPI scheme enables effective geometric distortion correction in IR-EPI data, with only a negligible increase in scan time. Consequently, the greater structural similarity to co-registered MP2RAGE significantly enhances T1 mapping accuracy, while providing rapid, whole-cerebrum acquisition at 7T.