Design of a 13-Channel Hybrid Array System for Foot/Ankle Magnetic Resonance Imaging at 7T/300MHz

TL;DR

This paper presents a novel 13-channel hybrid array system utilizing microstrip lines and high permittivity materials for enhanced foot and ankle MRI at 7T, improving coverage and field uniformity.

Contribution

The work introduces a new 13-channel hybrid array design combining microstrips and a volume coil for ultrahigh field foot/ankle MRI at 7T, with electromagnetic validation.

Findings

Demonstrates improved magnetic field distribution at 7T

Shows reduced SAR and coupling between elements

Provides extensive coverage and uniformity in imaging

Abstract

Microstrip lines are being used in MR applications due to their unique properties, such as reduced radiation loss, high-frequency capability, and reduced perturbation of sample loading to the RF coil compared to conventional coils. Here, we present the design of the 13-channel hybrid array consisting of 12 Microstrips, 1 volume half birdcage coil placed on the foot/ankle phantom, and high permittivity materials to cover the maximum area of the subject at 7T/300MHz. We demonstrate using electromagnetic simulations, magnetic field distribution, SAR performance, and the coupling performance of the array elements. This work provides an ultrahigh field multichannel RF solution to lower extremity MR imaging with excellent imaging coverage and field uniformity.