LAUSR

OBJECTIVES To determine the differentiating features of autoimmune central nervous system (CNS) vasculitis and multiple sclerosis (MS) on susceptibility-weighted imaging (SWI). METHODS Seventy-three patients (27 with autoimmune CNS vasculitis and 46 with MS) who underwent magnetic resonance imaging with SWI sequence were included. The features of lesions and distinct SWI findings were investigated in both diseases. RESULTS On SWI, autoimmune CNS vasculitis presented with a higher prevalence of multiple microbleeds (48.1%), cortical superficial siderosis (70.4%), and tortuosity of the vascular route (59.3%) than were found in MS (p < 0.001, p < 0.001, and p = 0.001, respectively). Multivariable logistic analysis showed that multiple microbleeds and cortical superficial siderosis were associated with a much higher probability of a diagnosis of autoimmune CNS vasculitis than of MS (OR 19.09, 95% CI 1.13-321.18, p = 0.041; and OR 13.20, 95% CI 2.22-78.30, p = 0.005, respectively). The presence of more than eleven lesions was associated with a lower probability of a diagnosis of autoimmune CNS vasculitis than of MS (OR 0.14, 95% CI 0.03-0.73, p = 0.020). CONCLUSIONS SWI may be a useful adjunct in distinguishing autoimmune CNS vasculitis from MS. The identification of multiple microbleeds and cortical superficial siderosis can point to a diagnosis of autoimmune CNS vasculitis.