title: Short-term evolution of individual enhancing MS lesions studied with magnetization transfer imaging.
abstract: We performed serial monthly magnetization transfer (MT) imaging to evaluate the prevalence and evolution of structural changes in individual enhancing lesions from patients with multiple sclerosis (MS). Every 4 weeks for 3 months, we obtained dual echo, magnetization transfer (MT) imaging and, 5 min after SD (0.1 mmol/kg) gadolinium-DTPA injection, T1-weighted scans from 10 patients with early relapsing-remitting MS. We measured the MT ratio (MTR) of enhancing lesions seen on the entry scans on co-registered quantitative MTR images at entry and during the follow up. Fourty-two enhancing lesions were identified on the entry scans. According to the "maximal random fluctuation" detected for the normal-appearing white matter MTR values, 16 (38%) lesions were classified as "increasing MTR" lesions, 21 (50%) as "stable MTR" lesions, and 5 (12%) as "decreasing MTR" lesions. The classification of the lesions after the first month of follow up strongly predicted the classification at the end of the follow up (chi squared = 20.35, p = 0.0004). These results indicate that the enhancing lesion population in MS is heterogeneous, and that reparative mechanisms occurring after blood-brain barrier opening are not efficient in only a minority of the enhancing lesions from patients with early relapsing-remitting MS.
authors.affiliation: Department of Neuroscience Scientific Institute Ospedale San Raffaele, University of Milan, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Filippi
authors.forename: M A
authors.initials: MA
authors.lastname: Rocca
authors.forename: M P
authors.initials: MP
authors.lastname: Sormani
authors.forename: C
authors.initials: C
authors.lastname: Pereira
authors.forename: G
authors.initials: G
authors.lastname: Comi
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009103:Multiple Sclerosis / Q000175:diagnosis* / Q000473:pathology