Optically controlled on-coil amplifier with RF monitoring feedback.

ABSTRACT:

Purpose

To develop a new optically controlled on-coil amplifier that facilitates safe use of multi-channel radiofrequency (RF) transmission in MRI by real-time monitoring of signal phase and amplitude.

Methods

Monitoring was carried out with a 4-channel prototype system by sensing, down sampling, digitizing, and optically transmitting the RF transmit signal to a remote PC to control the amplifiers. Performance was evaluated with benchtop and 7 T MRI experiments.

Results

Monitored amplitude and phase were stable across repetitions and had standard deviations of 0.061 μT and 0.0073 rad, respectively. The feedback system allowed inter-channel phase and B₁ amplitude to be adjusted within two iterations. MRI experiments demonstrated the feasibility of this appro

SUBMITTER: Gudino N 

PROVIDER: S-EPMC5839114 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature