Closely Spaced Double-Row Microstrip RF Arrays for Parallel MR Imaging at Ultrahigh Fields

摘要

Radiofrequency (RF) coil arrays with high count of elements, e.g., closely spaced multi-row arrays, exhibit superior parallel imaging performance in magnetic resonance imaging (MRI). However, it is technically challenging and time-consuming to build multi-row arrays due to complex coupling issues. This paper presents a novel and simple method for closely spaced multi-row RF array designs. Induced current elimination decoupling method has shown the capability of reducing coupling between microstrip elements from different rows. In this study, its capability for decoupling array elements from the same row was investigated and validated by bench tests, with an isolation improvement from -8.9 to -20.7 dB. Based on this feature, a closely spaced double-row microstrip array with 16 elements was built at 7 T. S (21) between any two elements of the 16-channel closely spaced double-row microstrip array was better than -14 dB. In addition, its feasibility and performance was validated by MRI experiments. No significant image reconstruction-related noise amplifications were observed for parallel imaging even when reduced factor (R) achieves 4. The experimental results demonstrated that the proposed design might be a simple and efficient approach in fabricating closely spaced multi-row RF arrays.