New technology detects changes in the brain beyond the lesions seen with normal MRI scans.
Since its inception, magnetic resonance imaging (MRI) has been lauded for its ultra-sensitivity in identifying plaques in the brain and spine of patients with multiple sclerosis (MS). In the years since, it has become vital for diagnosing MS, in addition to gauging response to treatment or disease progression.
But despite the capabilities of standard MRI — equipped with conventional 1.5-, or 3-tesla (T) magnetic field strength — the technology isn't sensitive enough to detect all the components of this neurodegenerative disease in which the body's immune system attacks the fatty protective myelin sheath surrounding nerve fibers.
Now, a new study published online Jan. 4 in the journal Radiology found that high-resolution MRI of neurochemicals termed MR spectroscopic imaging at 7.0 T can help visualize pathologic findings beyond the lesions in participants with multiple sclerosis. It detected MS-relevant neurochemical changes in the normal-appearing white matter and cortical gray matter of the brain that were associated with patients' disability.
The research was led by Eva Heckova, Ph.D., a postdoctoral researcher in the High Field MRCentre at the Medical University of Vienna in Austria.
"If the results are confirmed in further clinical longitudinal studies, MR spectroscopic imaging could become a standard imaging tool for initial diagnosis, for disease progression and therapy monitoring," Heckova says.
MR spectropic imaging allows for assessment of brain metabolism and is of keen interest in MS, where MRI showing merely structure cannot adequately shed light on microscopic components of disease activity.
The study recruited 65 participants with MS and 20 age- and sex-matched healthy controls, with an average age of 32, between January 2016 and December 2017. Metabolic ratios were obtained in white matter lesions, normal-appearing white matter and cortical gray matter regions.
MR spectroscopic imaging at 7.0 T permitted visualization of brain metabolic alterations, particularly those related to neuroinflammation, which cannot be visible with conventional T1- or T2-weighted MRI.
“Seven-tesla MR spectroscopy offers improved signal-to-noise ratios and improved spectral resolution compared with lower field strengths, such as 3.0 and 1.5T,” Peter B. Barker, D.Phil., professor of radiology and oncology at the Johns Hopkins University School of Medicine in Baltimore, wrote in an editorial accompanying the trial’s results. “As a result, more compounds can be detected with higher accuracy. However, before these improvements can be realized in practice, many engineering challenges have to be overcome ...”
The National Multiple Sclerosis Society expressed optimism that this trial could pave the way toward better diagnostic tools. "We find this research finding to be intriguing and encourage the research team to continue to explore the utility of this approach in the diagnosis of MS,” says Julie Fiol, the society's associate vice president for healthcare access.