University of Nottingham researchers, in collaboration with the Centre for Kidney Research and Innovation (CKRI) in the U.K., are developing sodium MRI as a potential, and promising, advance in scanning technology. The research team has been awarded an MRC Discovery Grant and a university investment, totaling £1 million, to explore and develop the potential of this diagnosis and monitoring tool, whose main application will be kidney disease.
Current magnetic resonance imaging (MRI) techniques rely on the hydrogen present in the body’s water and fat to produce scans. However, this technique does not produce sufficiently detailed information on tissue health and disease progression. Sodium MRI uses much smaller sodium ions, naturally occurring in the body and involved in many functions associated with pathology, as biomarkers for imaging.
Despite its potential, imaging by sodium detection is challenging due to the poor detectability of the sodium signal in biological tissue in currently available MRI scanners. The size of the molecules is, however, this technique’s greatest asset, as the small sodium ions can give a much more detailed and accurate picture of the structure and health of an organ. The research team plans to use high and ultra-high magnetic field scanners to circumvent detectability obstacles, in a process that will involve MRI coils for sodium imaging as receivers of radio-frequency signals in the MRI scan, tuned to the specific frequency of sodium ions.
The team will focus on kidney disease, as kidneys are important in regulating sodium levels in the body. By imaging the distribution of sodium in a healthy kidney, researchers can then compare it to a diseased kidney, potentially recovering key information regarding diagnosis, disease progression, adequacy of treatments, and the importance of sodium and water balance in dialysis.
“If we can image how sodium is distributed in the kidney and how that differs in a diseased kidney, the impact on the diagnosis and treatment of kidney injury or disease is potentially great,” Dr. Susan Francis, a study co-researcher with the university’s Sir Peter Mansfield Imaging Centre (SPMIC), said in a news release.
New insights in other diseases might also be possible. “Sodium accumulation in the skin is a biomarker for kidney stress but we will also be examining how salt is distributed in the skin and muscle. This has lots of clinical applications, for diseases like muscular dystrophy for example,” Dr. Francis said. “Theoretically we should also be able to study sodium concentration in red blood cells which again has major implications for disease diagnosis and treatment. The technique will give a picture of the body’s naturally occurring sodium and how it is trafficked in the body and will not require any invasive addition of sodium to the scanned subject.”
The research project will involve the scanning of healthy volunteers, combining conventional MRI to track water in the body with sodium MRI to analyze the concentration and behavior of sodium ions. Chronic kidney disease or acute kidney injury patients will then participate in a second smaller trial.