Comparison of simulated parallel transmit body arrays at 3 T using excitation uniformity, global SAR, local SAR, and power efficiency metrics.

ABSTRACT:

Purpose

We compare the performance of eight parallel transmit (pTx) body arrays with up to 32 channels and a standard birdcage design. Excitation uniformity, local specific absorption rate (SAR), global SAR, and power metrics are analyzed in the torso at 3 T for radiofrequency (RF)-shimming and 2-spoke excitations.

Methods

We used a fast cosimulation strategy for field calculation in the presence of coupling between transmit channels. We designed spoke pulses using magnitude least squares optimization with explicit constraint of SAR and power and compared the performance of the different pTx coils using the L-curve method.

Results

PTx arrays outperformed the conventional birdcage coil in all metrics except peak and average power efficiency. The presence of coupling ex

SUBMITTER: Guerin B 

PROVIDER: S-EPMC4201892 | biostudies-literature | 2015 Mar

REPOSITORIES: biostudies-literature