RF Power Amplifier Drift Compensation for Reliable B1 Mapping Using Bloch-Siegert Technique

Motivation: RFPA drift affects reproducibility of B1+ mappingGoal(s): The goal of study is to investigate factors influencing RFPA output drift and introducing a real-time feedback mechanism to compensate for driftApproach: B1+ with Bloch-Siegert shift technique is measured in a repetitive manner and reproducibility of maps is assessed. The RFPA output is continuously monitored through the use of DICOs, and adjustments to the transmit voltage are made to compensate for driftResults: The findings indicate that RFPA output drift is more noticeable with extended RF pulses and shorter TR. Implementing real-time drift correction effectively minimizes drift, leading to enhanced stability in B1+ mapsImpact: Our demonstration of real-time feedback to mitigate RFPA drift enhances measurement accuracy and reproducibility. This approach can be advantageous to achieve the consistency and reliability of research, particularly in the context of multi-center studies.