Self Shielding Multi-turn RF Surface Coil Planar Arrays for Low-field MRI at 2MHz

Motivation: Low field MRI using RF based gradients can reduce both its cost and bulk. Multi-channel RF arrays can enable this. Effective methods to decouple these coils and mitigate EMI are necessary for building efficient RF encoding based systems. Goal(s): To improve multi-channel RF array performance for low field MRI and automatically reject EMI. Approach: Develop an array of multi-turn surface coils with concentric shields. These are verified with an EMI rejection test and geometric decoupling tests. Results: These coils automatically reject environmental noise and add two additional geometric coupling modes when used in an array, allowing for more array configurations. Impact: RF array decoupling and EMI mitigation are challenging at low-field. We develop a method to decouple RF coil arrays by leveraging counter-wound multiturn surface coils allowing for additional decoupling modes. These coils are also self-shielded, providing added EMI mitigation.