Dependence of Scan Parameters on Nerve Fiber Crossing Depiction in Diffusion Spectrum Imaging in Clinical Practice.

OBJECTIVE: The objective of this study was to show the effect of the number of sampling points (NS) and the maximum b value (bmax) on fiber crossing detection in diffusion spectrum imaging (DSI) in clinical practice.

METHODS: We performed 3-Tesla DSI in which we changed the NS (62-258) while keeping bmax at 8000 s/mm and in which we changed the bmax (4000-8000 s/mm) while keeping the NS at 129. The superior longitudinal fasciculus volume and the proportion of nerve voxels in which at least 2 (Rcr2) or 3 (Rcr3) nerve fiber bundles crossed were calculated.

RESULTS: When bmax was set to 8000 s/mm, mean Rcr2 and Rcr3 values and superior longitudinal fasciculus volumes significantly increased with higher NSs, but they did not significantly change when we varied bmax with 129 NS.

CONCLUSIONS: Depiction sensitivity of nerve fiber crossing in DSI improves at higher NS and bmax settings, but a bmax insensitivity appears at an intermediate NS such as 129.