title: Parallel traveling-wave MRI: a feasibility study.
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 B 1- 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 B(1) fields and improve the parallel imaging performance. The proposed method is also validated by using 7T MR imaging experiments.
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA.
authors.forename: Yong
authors.initials: Y
authors.lastname: Pang
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Vigneron
authors.forename: Xiaoliang
authors.initials: X
authors.lastname: Zhang
mesh_terms: D005240:Feasibility Studies; D006257:Head; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008953:Models, Anatomic; D019047:Phantoms, Imaging; D012680:Sensitivity and Specificity