Metamaterials can reduce MRI scanning times by 50%

A group of researchers from Russia, Australia and the Netherlands has developed a technology that can reduce magnetic resonance imaging (MRI) scanning times by more than 50%, allowing hospitals to drastically increase the number of scans without changing their equipment. This extraordinary leap in efficiency is achieved by placing a layer of metamaterials onto the bed of the scanner, thereby improving the signal-to-noise ratio.

The details of this research appear in a paper in Advanced Materials. This patent-pending technology is currently being co-developed by MediWise, a UK company that specializes in commercializing metamaterials for medical applications.

MRI scanning is a commonly-used analytical technique in medicine, biology and neurology for monitoring subtle physiological changes in internal organs. For instance, a timely MRI procedure can detect tissues affected by cancer at the earliest stage of the disease. However, effective MRI diagnostics depends almost entirely on the quality of the resulting MRI images.

Now, the group of Russian, Australian and Dutch researchers has demonstrated that the quality of MRI images can be substantially increased with the aid of metamaterials – artificial periodic structures that can interact with electromagnetic radiation in an extraordinary fashion.

"This is the first real demonstration of the practical potential of metamaterials for MRI imaging enhancement and scanning time reduction, " says Yuri Kivshar, head of the Nonlinear Physics Centre at the Australian National University in Canberra, and co-author of the paper. "Our research may evolve into new healthcare applications and commercial products."

By placing a specially-designed metamaterial comprising an array of metallic wires under the object being studied in an MRI scanner, the researchers showed that it is possible to increase the signal-to-noise ratio in the scanned area. This means that, compared to an ordinary MRI scanner, either a higher resolution image can be obtained over the same scanning time or an image with the same resolution can be obtained in a shorter time.

In addition, the metamaterial is able to suppress the electric field that can cause tissue heating – a phenomenon that may compromise the safety of the whole MRI procedure. This problem has recently become even more pressing with the arrival of high-field and ultra-high-field MRI scanners for medical applications. These high-field MRI scanners can produce higher-resolution images but at the expense of greater tissue heating.

By using the metamaterial, however, the scientific group managed to avoid tissue heating entirely, while still preserving high resolution. Furthermore, this approach does not require making any changes to the hardware of the MRI scanner; instead, it utilizes an inexpensive functional add-on device that can be used with any existing MRI scanner.

"Our metamaterial can be embedded directly into the patient table of any commercially available MRI scanner. However, in the future we see even more potential in the concept of special smart clothing for MRI scanning," says Alexey Slobozhanyuk, first author of the paper and a researcher at the International Laboratory of Applied Radiophysics at ITMO University in St Petersburg, Russia.

"Stripes of our metamaterial can be sewn in the clothes. The examination of patients, wearing such clothes, would lead to higher resolution MRI images, while the special design will enable a homogeneous enhancement of the signal-to-noise ratio, which does not pose any risk to the patients' health. As a result, with metamaterials you will be able to improve the characteristics of low-field MRI to the extent that their functionality is comparable to high-field MRI."

The duration of an MRI exam can also prove problematic for patients. In ordinary MRI devices, the scanning may last from 15 to 60 minutes, and during this time the patient must remain completely still. The possibility of achieving detailed images in a shorter time will make the procedure more convenient for the patient and could also reduce queue times in hospitals.

"Our idea of using metamaterials in order to receive images with higher detailization will allow doctors to localize and study oncological diseases, " says Kivshar. "Based on the images obtained with an MRI scanner, the surgeon determines the structure of the inflammation, which afterwards will serve as a blueprint for his scalpel during the operation."

"Metamaterials have been proven to add value through their ability to process electromagnetic and sound waves in ways that no natural material can do," comments George Palikaras, founder and CEO of MediWise. "This leads to emerging business opportunities creating genuinely disruptive products. The scientific field of metamaterials is rapidly evolving and impacting traditional industries such as aerospace, telecoms, cleantech and now healthcare. The technology has the potential to extend the life of MRI imaging machines but, more importantly, it will make the scan quicker, more accurate and safer to patients. We are honored to work alongside world-leading academic partners, and to help advance this important innovation from the laboratory to the marketplace."

This story is adapted from material from ITMO University, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.