Coupled stack-up volume RF coils for low-field MR imaging

Motivation: Low-field MRI has garnered significant attention in recent years due to its unique advantages in safety, cost-effectiveness and accessibility. However, lower field strength comes with an inherently lower SNR as its primary limitation. Goal(s): In this work, we introduce a novel volume RF coil design using coupled stack-up resonators to mitigate this challenge. Approach: To demonstrate the proposed design, we take 0.5T as an example field strength and designed a prototype coupled stack-up volume coil operating in the 20MHz range. Results: Compared to the birdcage coil, the proposed design significantly improves RF field efficiency and homogeneity, ultimately enhancing the performance of low-field MRI. Impact: The proposed stack-up volume coil outperforms the standard birdcage coil in B1 efficiency and field homogeneity at low fields, ultimately improving the performance of low-field MRI and advancing its applications.