Ceramic resonators for targeted clinical magnetic resonance imaging of the breast

Alena Shchelokova,Elizaveta Nenasheva,Viacheslav Ivanov,Irina Melchakova,Anna Andreychenko,Egor Kretov,Svetlana Serebryakova,Alexey Slobozhanyuk,Ivan Sushkov,Anna Mikhailovskaya,Pavel Belov

doi:10.1038/s41467-020-17598-3

Abstract

Currently, human magnetic resonance (MR) examinations are becoming highly specialized with a pre-defined and often relatively small target in the body. Conventionally, clinical MR equipment is designed to be universal that compromises its efficiency for small targets. Here, we present a concept for targeted clinical magnetic resonance imaging (MRI), which can be directly integrated into the existing clinical MR systems, and demonstrate its feasibility for breast imaging. The concept comprises spatial redistribution and passive focusing of the radiofrequency magnetic flux with the aid of an artificial resonator to maximize the efficiency of a conventional MR system for the area of interest. The approach offers the prospect of a targeted MRI and brings novel opportunities for high quality specialized MR examinations within any existing MR system.

Highlights

Human magnetic resonance (MR) examinations are becoming highly specialized with a pre-defined and often relatively small target in the body
Dielectric materials are widely used in ultra-high field magnetic resonance imaging (MRI) with static field strength 7 Tesla to enhance RF transmit efficiency locally and to reduce the specific absorption rate (SAR)[15,16,17,18]
The targeted clinical MRI concept uses a artificial resonator, which consists of several dielectric discs with a very high relative permittivity separated by specific gaps filled with a low dielectric constant material (Fig. 1c)

Summary

Introduction

Human magnetic resonance (MR) examinations are becoming highly specialized with a pre-defined and often relatively small target in the body. The conventional concept of excitation and reception of the electromagnetic signal at clinical MR systems (i.e., 1.5–3 Tesla) includes a large, human-sized transmit radiofrequency (RF) volume body birdcage coil and receive-only surface coil (Fig. 1a) This combination provides acceptable image quality of MR examinations of the whole body as well as body parts or organs but has some limitations in the current state-of-the-art. These limitations are exceptionally prominent for a modern trend of highly specialized clinical MR investigations with a relatively small (compared to average body size) target (e.g., the head, spine, joint, breast)[2]. They usually degrade MR image quality or their reconstruction time is unacceptably long for clinical workflow

Methods

Results

Conclusion