Higher Strength MRI Offers Greater Detection of Cortical Lesions in MS

Cortical lesions play a major role in the progression of multiple sclerosis (MS). A recent study looked to longitudinally characterize the development and evolution of cortical lesions in MS across the cortical width, as well as their relationship with white matter lesion accrual.

The study enrolled 20 participants with relapsing-remitting MS and 13 with secondary progressive MS, along with 10 healthy age-matched controls, from 2010 to 2016. The patients underwent 2 imaging sessions (mean interval, 1.5 years), which used 7.0-Tesla magnetic resonance imaging (MRI) for T2-weighted gradient-echo images for cortical and white matter lesion segmentation and 3.0-T T1-weighted images for cortical surface reconstruction and cortical thickness estimation. This type of MRI scanner is more than twice as powerful as more everyday versions and is more sensitive to cortical lesions.

The authors found that the 7T MRI was able to detect cortical lesions more often than what had been seen in previous studies, and the images showed that 25 of the study participants had formed new cortical lesions. Additionally, the images showed that the number of lesions that formed in the cortical region was double the number that grew in the brain’s white matter. The total volume of cortical lesions identified was determined as an indicator of neurological disability.

“We also found that these lesions can predict disability progression more than white matter lesions, which are the typical lesions of MS we’ve been studying for years,” said senior study author Caterina Mainero, MD, PhD in an interview.

The study found that the cortical lesions were more likely to concentrate on the brain’s surface in the sulci. The authors suggested that the flow of the fluid surrounding the brain and spine may be more limited in these areas, thus making the sulci more prone to inflammation.

When monitoring individuals with MS, physicians should take into consideration the key role that cortical lesions play in the progression of the disease, wrote the authors. The researchers will look to replicate these findings in a larger population of patients with MS in future studies.

Reference

Treaba C, Granberg T, Sormani M, et al. Longitudinal characterization of cortical lesion development and evolution in multiple sclerosis with 7.0-T MRI [published online April 9, 2019]. Radiology.doi.org/10.1148/radiol.2019181719