Magnetic resonance imaging (MRI) is one of the most valuable tools doctors use to diagnose disease. However, even with today’s advanced scanners, it is still difficult to produce clear images of some areas. The deep structures of the brain and the delicate tissues of the eyes and surrounding orbits are particularly challenging because of the hardware responsible for transmitting and receiving high-frequency signals.
Now, a team led by Nandita Saha, a doctoral student in Professor Thoralf Niendorff’s Ultra-High Field Magnetic Resonance Experimental Laboratory at the Max Delbrück Center, has developed a new MRI antenna based on advanced engineering materials. This innovation produces clearer images in less time and can be integrated into existing MRI systems rather than requiring an entirely new machine. Their discovery is advanced materials.
The project brought together experts in MRI physics, clinical ophthalmology, and translational imaging from the Max Delbrück Center and Rostock University Medical Center. Rostock researchers are also helping validate the technology for future clinical use.
“By using the concept of metamaterials, we were able to guide radio frequency fields more efficiently and demonstrate how advanced physics can directly improve medical images,” said Niendorff, senior author of the paper. “This study points the way to faster, clearer MRI scans that could benefit patients in many clinical areas.”
Metamaterials improve MRI performance
MRI scanners create images by sending radio frequency (RF) signals into the body while applying a strong magnetic field. When the tissue responds to these signals, the scanner collects the information needed to generate an image. Generally, a stronger signal will produce a clearer, more detailed scan.
Traditional MRI antennas, also known as RF coils, are often unable to collect sufficient signals from tissues located deep within the body or in anatomically complex areas. As a result, image quality may be reduced and scanning sessions may take longer.
To overcome this limitation, researchers incorporated metamaterials directly into MRI antennas. Metamaterials are specially designed structures that interact with electromagnetic waves in ways that natural materials cannot. In testing, the new antenna strengthened the signal from the target tissue, increased spatial resolution, improved image clarity and accelerated data collection.
An important advantage is that the antenna is compatible with existing MRI equipment, eliminating the need for expensive new infrastructure. The researchers tested their design by imaging the eyes and orbits of volunteers using a 7.0 Tesla MRI scanner.
“Our study shows clear relevance for ophthalmological applications, as it can facilitate anatomically detailed and high spatial resolution MRI of the eye,” said co-author of the paper Professor Oliver Stacks from the University of Rostock’s Faculty of Medicine. “This offers the possibility of opening a window into the eye and into (patho)physiological processes that have hitherto been largely inaccessible.”
Possibilities beyond eye image processing
“Our goal was to reimagine MRI hardware from the modern physics of antenna design,” Saha adds.
He said the technology could also be applied to protect sensitive areas of the body during MRI scans by reducing unnecessary heating around medical implants. Additionally, MRI-guided cancer therapy could be improved by more precisely targeting RF energy for procedures such as tumor hyperthermia and thermal tissue ablation.
Faster scans and better diagnosis
MRI exams can be time-consuming and uncomfortable because they have difficulty capturing important anatomical details, especially if repeat scans are required. By producing clearer images more quickly, the new antenna can reduce scan times and give doctors more confidence in their diagnoses.
Because the antenna is compact and lightweight, it can also be customized to different parts of the body, potentially improving patient comfort during imaging.
Niendorff said the design could eventually be adapted to MRI systems that operate at both lower and higher field strengths than 7.0 Tesla. It could also be tailored to image organs beyond the eyes, orbits and brain, and could be used to monitor metabolism and track how drugs move through the body.
The technology could also improve specialized MRI techniques that image atoms other than hydrogen, such as sodium and fluorine, by producing stronger signals and higher-quality images.
“Imaging hardware innovations have the potential to transform diagnostics, and this study is an important step towards the next generation of MRI technology,” said study co-author Dr Eva Beller from Rostock University Medical Center.
next step
The research team is preparing a large-scale clinical study involving multiple hospitals while modifying the antennae for additional organs, including the heart and kidneys. The long-standing cooperation between Stax and Niendorff will continue through the appointment of mutual visiting researchers.
This project was funded by the DFG as a collaboration between the Max Delbrück Center and the Medical University of Rostock.
