Optimization of pseudo-continuous arterial spin labeling at 7T with parallel transmission B1 shimming.

ABSTRACT:

Purpose

To optimize pseudo-continuous arterial spin labeling (pCASL) for 7 T, and to further improve the labeling efficiency with parallel RF transmission transmit B₁ ( B1+ ) shimming.

Methods

pCASL parameters were optimized based on B1+/B0 field distributions at 7 T with simulation. To increase labeling efficiency, the B1+ amplitude at inflowing arteries was increased with parallel RF transmission B1+ shimming. The "indv-shim" with shimming weights calculated for each individual subject, and the "univ-shim" with universal weights calculated on a group of 12 subjects, were compared with circular polarized (CP) shim. The optimized pCASL sequences with three B1+ shimming modes (indv-shim, univ-shim, and CP-shim) were evaluated in 6 subjects who underwent two repeate

SUBMITTER: Wang K 

PROVIDER: S-EPMC8616784 | biostudies-literature | 2022 Jan

REPOSITORIES: biostudies-literature