Safety and imaging performance of two-channel RF shimming for fetal MRI at 3T.

ABSTRACT:

Purpose

This study investigates whether two-channel radiofrequency (RF) shimming can improve imaging without increasing specific absorption rate (SAR) for fetal MRI at 3T.

Methods

Transmit field ( B1+ ) average and variation in the fetus was simulated in seven numerical pregnant body models. Safety was quantified by maternal and fetal peak local SAR and fetal average SAR. The shim parameter space was divided into improved B1+ (magnitude and homogeneity) and improved SAR regions, and an overlap where RF shimming improved both classes of metrics compared with birdcage mode was assessed. Additionally, the effect of fetal position, tissue detail, and dielectric properties on transmit field and SAR was studied.

Results

A region of subject-specific RF shim parameter space i

SUBMITTER: Yetisir F 

PROVIDER: S-EPMC8530882 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature