Single-shot diffusion trace spectroscopic imaging using tetrahedral encoding with semi-LASER and radial echo-planar trajectories at 7T

Motivation: We show the first demonstration of single-shot diffusion trace-weighted radial echo planar spectroscopic imaging with tetrahedral diffusion encoding in both phantom and in vivo at 7T. Goal(s): The advantage of the single-shot DW-REPS is the reduction of the measurement time. This proof-of-concept study applies radial EPSI at 7T for diffusion trace-weighted MRSI. Approach: Trace ADCs from 3 phantom and 2 in vivo datasets were determined from single-shot DW-REPSI acquisitions. Results: Preliminary results show good agreement in the estimated phantom ADC values, while in vivo trace ADCs are generally within the expected range although the values tend to be slightly higher than previously reported. Impact: Our preliminary results indicate a promising approach for determining the orientation-independent trace ADC value with DW-REPSI at 7T. This technique can reduce the total acquisition time for DW-MRSI studies relevant for probing the intracellular properties underlying pathological conditions.