Local SAR management strategies to use two-channel RF shimming for fetal MRI at 3 T.

ABSTRACT:

Purpose

This study evaluates the imaging performance of two-channel RF-shimming for fetal MRI at 3 T using four different local specific absorption rate (SAR) management strategies.

Methods

Due to the ambiguity of safe local SAR levels for fetal MRI, local SAR limits for RF shimming were determined based on either each individual's own SAR levels in standard imaging mode (CP mode) or the maximum SAR level observed across seven pregnant body models in CP mode. Local SAR was constrained either indirectly by further constraining the whole-body SAR (wbSAR) or directly by using subject-specific local SAR models. Each strategy was evaluated by the improvement of the transmit field efficiency (average |B₁ ⁺ |) and nonuniformity (|B₁ ⁺ | v

SUBMITTER: Yetisir F 

PROVIDER: S-EPMC10843691 | biostudies-literature | 2024 Mar

REPOSITORIES: biostudies-literature