Closely-spaced double-row microstrip RF arrays for parallel MR imaging at ultrahigh fields.
Radiofrequency (RF) coil arrays with high count of elements, e.g., closely-spaced multi-row arrays, exhibit superior parallel imaging performance in 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 (ICE) 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 dB to -20.7 dB. Based on this feature, a closely-spaced double-row microstrip array with 16 elements was built at 7T.S21between any two elements of the 16-channel closely-spaced 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.
Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China ; Beijing Engineering Research Center of Radiographic Techniques and Equipment, Beijing 100049, China.
Xinqiang
X
Yan
State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
Rong
R
Xue
Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California 94158, USA ; UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, California 94158, USA.
Xiaoliang
X
Zhang
Microstrip; RF array; decouple; induced current elimination (ICE); magnetic resonance image (MRI); parallel imaging