Newly updated international guidelines on the use of MRI in diagnosis and monitoring of multiple sclerosis have made several major changes to the previous recommendations released in 2015, based on evolving evidence in recent years.
The new recommendations on MRI are included in a position statement released by the Magnetic Resonance Imaging in Multiple Sclerosis study group, the Consortium of Multiple Sclerosis Centres and the North American Imaging in Multiple Sclerosis Cooperative MRI guidelines working group (MAGNIMS–CMSC–NAIMS).
Published in Lancet Neurology, the consensus statement recommends changes in MRI acquisition protocols, such as emphasising the value of three dimensional-fluid-attenuated inversion recovery as the core brain pulse sequence to improve diagnostic accuracy and ability to identify new lesions to monitor treatment effectiveness.
The new guidelines provide recommendations for the judicious use of gadolinium-based contrast agents and also extend recommendations on the use of MRI in patients with multiple sclerosis in childhood, during pregnancy, and in the post-partum period.
“In these new recommendations, we further simplified and shortened the brain MRI protocol for monitoring purposes, thereby making it easier and more likely to be used than previous guidelines,” the authors wrote.
“We also recommend a new baseline brain MRI scan without gadolinium at least three months after treatment initiation and annual follow-up scans after that without gadolinium.”
The writing group, led by Prof Mike P Wattjes of the Department of Diagnostic and Interventional Neuroradiology, Hannover Medical School, Germany, said the recommendations reflected evolving safety concerns about the repetitive administration of intravenous gadolinium-based contrast agents (GBCAs) due to the potential risk of gadolinium accumulation in the brain
“As GBCAs are not necessary in many clinical situations, particularly during monitoring of treatments for multiple sclerosis, their judicious and scarce use seems prudent,” they advised.
The guidelines also concluded that there was not enough evidence to recommend spinal cord MRI for routine follow-up monitoring of disease activity in patients with MS, as it was technically challenging and would disproportionately increase the scanning time.
“However, obtaining spinal cord MRI is important for diagnosis, when assessing the initial extent of CNS involvement (ie, disease burden), and in other special circumstances, including unexplained and unexpected disease worsening and the possibility of a diagnosis other than multiple sclerosis,” the authors said.
And despite the accumulating evidence, the guideline writing group decided that they could not yet recommend implementation of volumetric analysis, newly described imaging features, and quantitative MRI measures in routine clinical practice.
The most promising of these techniques were high-resolution susceptibility-based MRI, for detecting the central vein sign and discriminating chronic active lesions, and new approaches to identifying cortical lesions. But validation studies in clinical practice were required, they said.
“The value of quantitative changes in brain and spinal cord volume measures as predictors of the evolution of multiple sclerosis and in monitoring the effects of treatment has been shown in research settings and clinical trials. However, to make implementation of volume measurements in routine clinical practice feasible, several potential sources of error—including, but not limited to, confounding physiological factors on brain volume measures and the accuracy, reproducibility, and value of volumetric tools—need to be appropriately accounted for and managed,” they wrote.
“Standardisation and implementation of new and potentially more sensitive and specific imaging techniques than those that are currently used represent two of the greatest challenges but also two of the greatest opportunities in the near future, particularly as new treatments focusing on neuroprotection, remyelination, and neuronal repair emerge,” they concluded.