Reed Relay-Switched Tuning Circuit for Stretchable RF Coils in Low Field, Portable MRI

Motivation: Portable low-field MRI opens doors for low-cost and point-of-care imaging, but comes at the expense of decreased SNR, resulting in inferior image quality. Goal(s): We aim to increase SNR with stretchable, subject-adaptable, helmet coils for low-field, portable MRI brain imaging. Specifically, a single-channel Tx/Rx volume coil for brain imaging at 72 mT. Approach: We use a flexible 3D printed former and elastic bands for stretchable coil former. To account for the coil’s variable inductance, we develop an MATLAB-controlled autotuning circuit, composed of 8 capacitor values that can be switched in/out via Reed relays. Results: We present a preliminary coil and autotuning system design. Impact: To unlock portable MRI's full potential, we must boost SNR without sacrificing portability or safety. Our solution involves stretchable RF coil caps that mold to the subject's head in conjunction with an auto-tuning system for optimal performance.