Transmission of travelling-wave with a simple waveguide for rodents MRI at 9.4 T

TL;DR

This paper demonstrates the use of a simple parallel-plate waveguide combined with a circular RF coil to achieve travelling-wave MRI imaging of rodents at 9.4 T, addressing B1 inhomogeneity issues in ultra high field MRI.

Contribution

It introduces a novel, simple waveguide design for travelling-wave MRI at 9.4 T in small animals, expanding the application of twMRI beyond clinical scanners.

Findings

Successful imaging of rats at 9.4 T using the proposed waveguide setup.

Reduction of B1 inhomogeneity in ultra high field small animal MRI.

Feasibility of simple waveguide designs for high-field animal MRI.

Abstract

Standard coils can cause inhomogeneities due to the standing wave patterns at ultra high field MRI. This B1 inhomogeneity can be overcome using the travelling-wave MRI (twMRI) approach. The ma- jority of twMRI research has been done with clinical MRI scanners at 7T or above. More recently, this concept has been also used with animal MRI systems, using circular-cross section waveguides and dielectric materials for both type of scanners. We have demonstrated that twMRI can be used at 3 T with clinical systems and a parallel-plate waveguide. Here, we investigated the use of a parallel- plate waveguide and a RF circular coil to generate rat images with an animal MRI at 9.4 T.