Quantitative susceptibility mapping (QSM) in deep gray matter as a neurodegeneration marker in relapsing-remitting and secondary-progressive multiple sclerosis

Purpose. The aim of the study was to investigate changes in iron distribution in the brain of patients with multiple sclerosis (MS) using magnetic resonance imaging (MRI) technique – quantitative susceptibility mapping (QSM) – in comparison with clinical data. Materials and methods. Three groups of patients were included in this prospective study: 47 patients with relapsing-remitting MS (RRMS), 20 patients with secondary progressive MS (SPMS) and 39 healthy controls. For all patients we collected clinical data, including history of present illness (H&P) and disability degree, and performed brain MRI followed by QSM maps obtaining and assessing relative magnetic susceptibility in subcortical structures. Results. We found an increase in magnetic susceptibility in the heads of the caudate nuclei and in putamen in patients with SPMS as compared to RRMS. At the same time, a decrease in magnetic susceptibility in the thalamic pulvinar was detected in patients with MS in the long term, but a sharp hyperintensity in conjunction with decreasing volume was observed in some patients. Conclusion. Increased magnetic susceptibility on the QSM in subcortical structures of the brain, reflecting iron content, is more typical for patients with SPMS, which may indicate the prognostic value of these changes.