Magnetic resonance imaging perfusion is associated with disease severity and activity in multiple sclerosis

Purpose The utility of perfusion weighted imaging in multiple sclerosis (MS) is not well investigated. The purpose of this study was to compare baseline normalized perfusion measures in subgroups of newly diagnosed MS patients. We wanted to test the hypothesis that this method can differentiate between groups defined according to disease severity and disease activity at one year follow-up. Methods Baseline magnetic resonance imaging (MRI) including a dynamic susceptibility contrast perfusion sequence was performed on a 1.5 Tesla scanner in 66 patients newly diagnosed with relapsing-remitting MS. From the baseline MRI, cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) maps were generated. Normalized (n) perfusion values were calculated by dividing each perfusion parameter obtained in white matter lesions by the same parameter obtained in normal appearing white matter. Neurological examination was performed at baseline and at follow-up approximately one year later to establish the multiple sclerosis severity score (MSSS) and evidence of disease activity (EDA). Results Baseline nMTT was lower in patients with MSSS>3.79 (p=0.016), in patients with EDA (p=0.041) and in patients with both MSSS>3.79 and EDA (p=0.032) at one-year follow-up. Baseline nCBF and nCBV did not differ between these groups. Conclusions Lower baseline nMTT was associated with higher disease severity and with presence of disease activity one year later in newly diagnosed MS patients. Further longitudinal studies are needed to confirm whether baseline normalized perfusion measures can differentiate between disease severity and disease activity subgroups over time. This is a post-peer-review, pre-copyedit version of an article published in Neuroradiology. The final authenticated version is available online at: http://dx.doi.org/10.1007/s00234-017-1849-4