title: Sensitivity of delayed gadolinium-enhanced MRI in multiple sclerosis.
abstract: BACKGROUND
  We performed this study to define the sensitivity of delayed gadolinium-enhanced magnetic resonance imaging (MRI) in detecting active lesions in the brains of patients with multiple sclerosis (MS).
  
  
  METHODS
  T1-weighted images were obtained in 27 patients with relapsing-remitting or secondary progressive MS before, 5-7 min and 20-30 min after the injection of 0.1 mmol/kg gadolinium-DTPA.
  
  
  RESULTS
  One-hundred-and-three enhancing lesions were found on the early and 110 on the delayed scans (increase=6.4%). Six patients had 8 additional lesions in the delayed scans, while 1 patient had 1 more lesion on the early scan. Two of the 12 (17%) patients with no enhancing lesions on the early scans had 2 enhancing lesions on the delayed scans. The average increase of enhancing lesion detection with delayed scanning was 14.5% for those patients who already had enhancing lesions on the early post-contrast scans. A significant increase of the enhancing lesion volume was found with delayed scanning (P=0.004).
  
  
  CONCLUSIONS
  These data indicate that it is possible to increase MRI sensitivity in detecting MS active lesions by delaying the scanning after gadolinium injection.
authors.affiliation: Department of Neurology, Scientific Institute Ospedale San Raffaele, University of Milan, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Filippi
authors.forename: T
authors.initials: T
authors.lastname: Yousry
authors.forename: M A
authors.initials: MA
authors.lastname: Rocca
authors.forename: G
authors.initials: G
authors.lastname: Fesl
authors.forename: R
authors.initials: R
authors.lastname: Voltz
authors.forename: G
authors.initials: G
authors.lastname: Comi
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D005682:Gadolinium / Q000493:pharmacokinetics; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000592:standards*; D008297:Male; D009103:Multiple Sclerosis / Q000473:pathology*; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D005682:Gadolinium