Improving SNR of 3T MRI using an Inductively Coupled Passive Birdcage

Motivation: MRI coils are typically connected to MRI systems via cables limiting patient comfort and restricting imaging modalities. Wireless (passive), inductively coupled coils offer benefits in terms of flexibility, patient comfort, and imaging capabilities, that were mainly demonstrated for 1.5T and lower field systems. Goal(s): This study aims to explore the applicability of inductively coupled, circularly polarized coil technology in 3T systems. Approach: The approach is evaluated by developing an inductively coupled birdcage resonator and measuring achievable SNR improvements. Results: Imaging experiments indicate that the coil can provide up to 7 dB of SNR improvement, here demonstrated over a spherical 18 cm gel phantom. Impact: Avoiding connecting cables in RF coil receivers will positively impact patient comfort and remove the risk of interference due to common mode currents. The design of an inductively coupled birdcage is presented, which provides an SNR improvement in 3T systems.