title: Ring and nodular multiple sclerosis lesions: a retrospective natural history study.
abstract: BACKGROUND
  In patients with multiple sclerosis (MS), contrast-enhancing lesions (CELs) on postcontrast MRI are considered markers of the inflammatory responses associated with blood-brain barrier breakdown. Based upon shape, CELs may be defined as nodular (nCEL) or ring (rCEL) lesions. Several short-term studies pointed towards the assumption that rCELs represent areas of a more aggressive inflammatory process.
  
  
  METHODS
  In the present long-term (i.e., 2 years) retrospective natural history study, we used monthly imaging to follow rCEL and nCELs evolution in 16 patients with MS during the natural history. New CELs were identified monthly on month 4-9 MRIs, using month 1-3 MRIs to ensure that all CELs were not previously enhancing. Chronic black holes (cBHs) were counted monthly upon CEL disappearance up to the 24th MRI. Generalized estimating equation methods investigated within-patient differences between rCELs and nCELs in volume and likelihood to convert into cBHs. Kaplan-Meier survival curves estimated differences in the length of persistence between cBHs originating from nCELs and cBHs deriving from rCELs.
  
  
  RESULTS
  Fifty-two new rCELs and 281 nCELs were identified. rCELs had larger mean (z = 5.06, p < or = 0.0001) volumes than nCELs. The proportion of cBHs from rCELs was similar (z = 1.81, p = 0.0710) to the proportion of cBHs from nCELs. Likewise, the length of persistence of cBHs deriving from rCELs was similar (chi(1)(2) = 2.339, p = 0.1262) to the duration of cBHs from nCELs.
  
  
  CONCLUSIONS
  Our data suggest that worse radiologic characteristics associated with the acute phase of ring contrast-enhancing lesions and nodular contrast-enhancing lesions do not necessarily reflect a poorer lesion outcome over time.
authors.affiliation: NIB-National Institute of Neurological Disorders and Stroke-NIH Building 10, Room 5C103, 10 Center Drive, Bethesda, MD 20892-1400, USA.
authors.forename: M
authors.initials: M
authors.lastname: Davis
authors.forename: S
authors.initials: S
authors.lastname: Auh
authors.forename: M
authors.initials: M
authors.lastname: Riva
authors.forename: N D
authors.initials: ND
authors.lastname: Richert
authors.forename: J A
authors.initials: JA
authors.lastname: Frank
authors.forename: H F
authors.initials: HF
authors.lastname: McFarland
authors.forename: F
authors.initials: F
authors.lastname: Bagnato
mesh_terms: D000328:Adult; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D003287:Contrast Media; D004185:Disability Evaluation; D018450:Disease Progression; D004660:Encephalitis / Q000188:drug therapy / Q000209:etiology / Q000473:pathology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008775:Methylprednisolone / Q000627:therapeutic use; D009103:Multiple Sclerosis / Q000150:complications / Q000473:pathology*; D011241:Prednisone / Q000627:therapeutic use; D012189:Retrospective Studies; D013223:Statistics as Topic; D013997:Time Factors
chemical_list: D000893:Anti-Inflammatory Agents; D003287:Contrast Media; D011241:Prednisone; D008775:Methylprednisolone