Direct imaging of radio-frequency modes via traveling wave magnetic resonance imaging

作者：Tonyushkin A^*; Deelchand D K; Van de Moortele P F; Adriany G; Kiruluta A

来源：Journal of Applied Physics, 2016, 119(2): 024904.

DOI：10.1063/1.4940019

We demonstrate an experimental method for direct 2D and 3D imaging of magnetic radio-frequency (rf) field distribution in metal-dielectric structures based on traveling wave (TW) magnetic resonance imaging (MRI) at ultra-high field (> 7 T). The typical apparatus would include an ultra-high field whole body or small bore MRI scanner, waveguide elements filled with MRI active dielectrics with predefined electric and magnetic properties, and TW rf transmit-receive probes. We validated the technique by obtaining TW MR images of the magnetic field distribution of the rf modes of circular waveguide filled with deionized water in a 16.4 T small-bore MRI scanner and compared the MR images with numerical simulations. Our MRI technique opens up a practical non-perturbed way of imaging of previously inaccessible rf field distribution of modes inside various shapes metal waveguides with inserted dielectric objects, including waveguide mode converters and transformers.

• 出版日期2016-1-14