title: Differential diagnosis and prognosis of T1-weighted post-gadolinium intralabyrinthine hyperintensities.
abstract: OBJECTIVE
  The aim of this longitudinal study is to describe the different intralabyrinthine lesions yielding high signal intensity on T1-weighted (T1W) images after intravenous gadolinium and then to analyze the follow-up of these patients.
  
  
  METHODS
  Thirty-seven patients were included and followed clinically and radiologically. A precise analysis of MR labyrinthine signals allowed exact depiction of the different lesions. Special interest is focused on the intralabyrinthine fluid signal on 3D high-resolution T2W images.
  
  
  RESULTS
  The enhanced T1W labyrinthine hyperintensities correspond to two different categories: intralabyrinthine enhancement (15 intralabyrinthine schwannomas, 13 labyrinthitis, 1 inflammatory granuloma) and spontaneous T1W hyperintensities (8 intralabyrinthine hemorrhages). Hemorrhagic lesions show a substantial decrease of the intralabyrinthine fluid signal on the 3D HRT2 that evolves to ossification. In labyrinthitis, the importance of the initial labyrinthine fluid signal decrease on the 3D HRT2 is well correlated with the hearing prognosis.
  
  
  CONCLUSIONS
  A meticulous analysis of inner ear lesions allows various intralabyrinthine lesions, in particular schwannomas, to be differentiated from labyrinthitis. T1W imaging without gadolinium is essential for the correct diagnosis of rapidly evolving hearing loss. In labyrinthitis and intralabyrinthine hemorrhage, 3D HRT2 brings an interesting prognostic factor for the chance of hearing recovery.
authors.affiliation: Department of Radiology, CHU Lille, Huriez Hospital INSERM, unit U703, University Nord of France, Lille, France. f-dubrulle@chru-lille.fr
authors.forename: F
authors.initials: F
authors.lastname: Dubrulle
authors.forename: R
authors.initials: R
authors.lastname: Kohler
authors.forename: C
authors.initials: C
authors.lastname: Vincent
authors.forename: P
authors.initials: P
authors.lastname: Puech
authors.forename: O
authors.initials: O
authors.lastname: Ernst
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003287:Contrast Media; D003937:Diagnosis, Differential; D004428:Ear Neoplasms / Q000175:diagnosis*; D007758:Ear, Inner / Q000473:pathology; D005260:Female; D005682:Gadolinium; D006801:Humans; D007759:Labyrinth Diseases / Q000175:diagnosis*; D007762:Labyrinthitis / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009442:Neurilemmoma / Q000175:diagnosis*; D011379:Prognosis; D055815:Young Adult
chemical_list: D003287:Contrast Media; D005682:Gadolinium