A monopole/loop dual-tuned RF coil for ultrahigh field MRI

Quantitative Imaging in Medicine and Surgery

Xinqiang Yan¹  Xiaoliang Zhang³  Rong Xue² 

[1] State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China;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;State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China;Beijing Institute for Brain Disorders, Beijing 100053, China;;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

关键词: Magnetic resonance image (MRI);    dual-tuned (DT);    radiofrequency coil;    sodium;    monopole;    loop;    decouple;    trap;    sensitivity;    signal-to-noise ratio (SNR);   

DOI  :  10.3978/j.issn.2223-4292.2014.08.03

学科分类：外科医学

来源: AME Publications

【 摘 要 】

Proton and heteronuclear MRI/MRS using dual-tuned (DT) coils could provide both anatomical and metabolic images without repositioning the subject. However, it is technologically challenging to attain sufficiently electromagnetic (EM) decoupling between the heteronuclear channel and proton channel, and keep the imaging areas and profiles of two nuclear channels highly matched. In this study, a hybrid monopole/loop technique was proposed for DT coil design and this technique was validated by implementing and testing a DT ¹H/²³Na coil for MR imaging at 7T. The RF fields of the monopole (¹H channel) and regular L/C loop (²³Na channel) were orthogonal and intrinsically EM decoupled. Bench measurement results demonstrated the isolation between the two nuclear channels was better than -28 dB at both nuclear frequencies. Compared with the conventional DT coil using trap circuits, the monopole/loop DT coil had higher MR sensitivity for sodium imaging. The experimental results indicated that the monopole/loop technique might be a simple and efficient design for multinuclear imaging at ultrahigh fields. Additionally, the proposed DT coils based on the monopole/loop technique can be used as building blocks in designing multichannel DT coil arrays.

【 授权许可】

Unknown