Positron Emission Tomography Classifies MS Lesion Subtypes

MRI with gadolinium contrast can differentiate acutely active from nonacute lesions but does not provide information about chronic lesions. In this study, investigators used a translocator protein radiotracer, [¹⁸F]-DPA-714-PET, to classify T2-weighted lesions based on inflammatory profile. White-matter lesions were classified as homogeneously active, rim-active, or nonactive. Included were 36 patients with MS (mean disease duration, 9 years), 12 with relapsing-remitting and 24 with progressive disease. PET imaging was done at baseline. Clinical assessments and MRI were conducted at baseline and 2 years.

Of 1335 T2-weighted lesions, 53% were homogeneously active, 6% rim-active, and 41% nonactive at baseline. On average, each patient had 20 h…