Parallel traveling-wave MRI: A feasibility study

Authors

  • Yong Pang,

    1. Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
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  • Daniel B. Vigneron,

    1. Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
    2. UCSF/UC Berkeley Joint Graduate Group in Bioengineering, Berkeley, California, USA
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  • Xiaoliang Zhang

    Corresponding author
    1. Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
    2. UCSF/UC Berkeley Joint Graduate Group in Bioengineering, Berkeley, California, USA
    • Department of Radiology and Biomedical Imaging, University of California San Francisco, Byers Hall, Room 102D, 1700 4th Street, San Francisco, CA 94158-2330
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Abstract

Traveling-wave magnetic resonance imaging utilizes far fields of a single-piece patch antenna in the magnet bore to generate radio frequency fields for imaging large-size samples, such as the human body. In this work, the feasibility of applying the “traveling-wave” technique to parallel imaging is studied using microstrip patch antenna arrays with both the numerical analysis and experimental tests. A specific patch array model is built and each array element is a microstrip patch antenna. Bench tests show that decoupling between two adjacent elements is better than -26-dB while matching of each element reaches -36-dB, demonstrating excellent isolation performance and impedance match capability. The sensitivity patterns are simulated and g-factors are calculated for both unloaded and loaded cases. The results on Bmath image sensitivity patterns and g-factors demonstrate the feasibility of the traveling-wave parallel imaging. Simulations also suggest that different array configuration such as patch shape, position and orientation leads to different sensitivity patterns and g-factor maps, which provides a way to manipulate B1 fields and improve the parallel imaging performance. The proposed method is also validated by using 7T MR imaging experiments. Magn Reson Med, 2011. © 2011 Wiley-Liss, Inc.

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