Lesions in the cortex, the most outer layer of the brain, have recently become part of the diagnostic criteria for multiple sclerosis (MS), but are notoriously hard to visualize when using conventional MRI-images (sequences). Piet Bouman, PhD candidate at the MS Center Amsterdam, and his colleagues have examined which MRI sequences could best be used in order to visualize cortical MS lesions. Bouman’ s results have been published in the renowned journal Brain.

The study shows that cortical MS lesions play a pivotal role in patients’ complaints and disease course. Cortical lesions are, however, highly inconspicuous on conventional clinical MRI sequences (T1, T2, FLAIR). In this study published in Brain, Bouman and colleagues have found that by the use of the more advanced MRI sequences Double Inversion Recovery (DIR) and Phase-Sensitive Inversion Recovery (PSIR), an increased number of cortical lesions can be visualized.

Piet Bouman

Post-mortem brain tissue

For this study, Bouman has used brain tissue from deceased patients with MS. MRI-scans were made with both conventional clinical sequences (T1, T2, FLAIR) and advanced sequences (DIR and PSIR). Then, the brains were extracted and a microscope was used to look for cortical lesions in the tissue. Next, for each MRI sequence, it was determined which cortical lesions were discernible and which were not. It was found that, when using advanced DIR and PSIR sequences, a higher number of cortical lesions were discernible than when using conventional clinical MRI sequences.

Broadening availability

Advanced MRI sequences DIR and PSIR are difficult to acquire. Hence, their availability is not self-evident in many peripheral and even university medical centers. Current research by Bouman focuses on broadening the availability of DIR and PSIR MRI sequences, in order to create a better understanding of how cortical lesions affect both physical and mental functioning of patients with MS. Furthermore, these MRI sequences could potentially speed up the diagnostic process of MS.

Read the original article by Piet M Bouman et al.: Histopathology-validated recommendations for cortical lesion imaging in multiple sclerosis.