Impact of slice-specific z-shimming on T2*-weighted EPI for functional MRI of the human spinal cord at 7 Tesla

Résumé fourni par la source

Motivation: Slice-specific z-shimming reduces signal losses in T2*-weighted EPI of the human spinal cord at 3T. Goal(s): To investigate its impact for acquisitions at 7T performed with thinner slices and shorter echo times that are less susceptible to signal losses. Approach: EPI images (16 slices, 0.8×0.8×3.0 mm3) with 31 different z-shim settings compensating linear field inhomogeneities within ±0.3 mT m-1 were acquired. For each slice, the image with the maximum signal in the spinal cord was determined and compared to the image without z-shim. Results: Averaged across 20 healthy volunteers, slice-specific z-shimming significantly improves overall EPI signal intensity and reduces signal variations across slices. Impact: Z-shimming can improve the signal intensity and homogeneity of T2*-weighted EPI of the human cervical spinal cord at 7T and could thus help to improve the performance of spinal cord fMRI.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.