Magnetic resonance imaging assessment of brain lesions for multiple sclerosis in relation to diagnosis and disability progression

Abstract

NTRODUCTION Multiple sclerosis (MS) is a major cause of neurological disability amongst young adults, with the global number diagnosed annually numbering almost 2.3 million people worldwide. Disability factors often found with MS are associated with lifestyle factors, genetics and biochemistry (Nelson, 2013). As monitoring the disease process over time has its own challenges, in such a context the need arises for a reliable biomarker/tool, like magnetic resonance imaging (MRI). Advances made with MRI technology and increased availability, since 2012, have enabled enhanced understanding and monitoring of specific pathological processes related to MS(Filippi et al., 2019). Recent studies show that 80% of MS patients have more MRI-detectable lesions when advanced sequences are used with either 1.5T or 3T magnets(Cahalane et al., 2018). METHOD Twenty-five participants with a confirmed diagnosis of MS and 25 age-matched controls enrolled for the study, with 7 participants (3 patients with MS and 4 controls), being unable to have the MRI scan, due to concerns related to either claustrophobia or illness. All participants had an MRI scan of the brain using a 3-T Siemens Skyra (Erlangen, Germany) scanner. The protocol used included fluid-attenuated inversion recovery (FLAIR) in both axial and sagittal planes, proton density (PD), T2 (in the coronal plane), magnetisation-prepared rapid acquisition gradient echo (MPRAGE), susceptibility-weighted imaging (SWI), diffusion tensor imaging (DTI), and readout segmentation of long variable echo-trains (RESOLVE) images were utilised for the lesion count. Other variables included were the genetic profiles of each participant and the assessment of disability, using the Expanded Disability Status Scale (EDSS), as well as the compiling of their biochemical, dietary and lifestyle information. RESULTS Although brain white matter lesions (WMLs) were found in both groups, an increased number of lesions was found in the MS group. Despite the WML volumes being significantly associated with the EDSS ((p<0.02), they were not found to be so with the use of age, disease duration or disease-modifying therapies (DMT). The Sequence-Adaptive Multimodal SEGmentation (SAMSEG) software identified WMLs in some control participants, with such spaces possibly accounting for vascularity and Virchow-Robin spaces, among others, since the age group represented was varied. CONCLUSION As an imaging modality, MRI is regularly evolving, with it having proven itself to continue playing an integral and pivotal role in the diagnosis and monitoring of brain pathologies.