A team of clinicians and scientists have released a report of magnetic resonance imaging (MRI) strategies that identify measures of neuroprotection and repair in patients with multiple sclerosis (MS). The full description of each imaging modality can be found in a recent edition of Neurology.
In November 2016, a group of clinicians and scientists with expertise in MRI use for MS convened at the North American Imaging in Multiple Sclerosis (NAIMS) Cooperative workshop. The team discussed a spectrum of imaging modalities for MS, specifically emerging techniques, and this discussion was synthesized into a manuscript that was dispersed to workshop attendees. The manuscript discussed repair of acute white matter (WM) lesions, repair of chronic WM lesions, repair of energy deficits, and repair and neuroprotection of special regions.
Monitoring T1 hypointensity evolution over time represents the most common MRI measure of acute WM lesion repair. The evolution of lesions may be identified with gadolinium enhancement patterns, the latter of which may relate to WM repair. Changes in magnetization transfer ratio (MTR) often correlate with evidence of both demyelination and remyelination. The sensitivity of the modality’s acquisition parameters and field strength as well as its pathologic nonspecificity are key challenges of MTR.
Myelin water imaging (MWI) is an MRI measure that images myelin-associated water to identify neuroprotection and repair. The good intrasite and intersite reliability as well as reproducibility of MWI across platforms makes this imaging approach ideal for clinical trials.
Susceptibility-weighted imaging (SWI) is another potential target for visualizing neuroprotection and chronic lesion repair. The benefits of SWI include high spatial resolution, short data acquisition times, and high signal-to-noise ratio.
“Imaging biomarkers of neuroprotection and repair are needed to accelerate the discovery of effective treatments for all stages of MS,” the researchers wrote.
“Based on the collective opinion of the NAIMS Cooperative, it is evident there are a number of promising techniques with different strengths and limitations. Selection of a specific technique will depend on a number of factors, including clinical setting, outcome being targeted, study design, mechanisms of action of candidate drugs, patient population, and resources.”
Oh J, Ontaneda D, Azevedo C, et al; North American Imaging in Multiple Sclerosis Cooperative. Imaging outcome measures of neuroprotection and repair in MS: a consensus statement from NAIMS [published online February 20, 2019]. Neurology. doi: 10.1212/WNL.0000000000007099