High dynamic range B 1 + mapping for the evaluation of parallel transmit arrays.

ABSTRACT:

Purpose

Demonstration of a high dynamic-range and high SNR method for acquiring absolute B1+$$ {\mathrm{B}}_1^{+} $$ maps from a combination of gradient echo and actual-flip-angle measurements that is especially useful during the construction of parallel-transmit arrays.

Methods

Low flip angle gradient echo images, acquired when transmitting with each channel individually, are used to compute relative B1+$$ {\mathrm{B}}_1^{+} $$ maps. Instead of computing these in a conventional manner, the equivalence of the problem to the ESPIRiT parallel image reconstruction method is used to compute B1+$$ {\mathrm{B}}_1^{+} $$ maps with a higher SNR. Absolute maps are generated by calibration against a single actual flip-angle acquisition when transmitting on all channels simultaneously.

SUBMITTER: Felder J 

PROVIDER: S-EPMC11680734 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature