title: Transport augmentation through the blood-inner ear barriers of guinea pigs treated with 3-nitropropionic acid and patients with acute hearing loss, visualized with 3.0 T MRI.
abstract: OBJECTIVE
  To visualize the permeability changes in the blood-inner ear barriers of guinea pigs with acute mitochondria dysfunction and in patients with acute hearing loss using contrast agent-enhanced MRI.
  
  
  METHODS
  An animal model of acute mitochondria dysfunction-induced hearing loss was created by introducing 3-nitropropionic acid (3-NP) intratympanically in guinea pigs. Vestibular disorder and hearing loss were evaluated. An MRI was performed at 2 h after either intravenous (IV) or intratympanic administration of dimeglumine gadopentetate (Gd-DTPA), using 3D fast-recovery fast spin-echo (FRFSE) and 3D fluid-attenuated inversion recovery (FLAIR) sequences. The inner ears of patients with acute hearing loss were imaged using a 3D-FLAIR sequence with a 3 T MRI machine at 2 h post-IV injection with Gd-DTPA at a routine dosage.
  
  
  RESULTS
  Guinea pigs treated with 3-NP showed severe hearing loss and vestibular dysfunction. MR imaging with a 3D-FLAIR sequence at 2 h post-IV injection of Gd-DTPA was an optimal method for visualizing transport augmentation through the blood-inner ear barriers. Apoptosis appeared in the stria vascularis and Reissner's membrane of cochleae treated with 3NP. Similar MRI changes were observed in patients with SSHL and Ménière's disease 2 h post-IV injection with Gd-DTPA using the 3D-FLAIR sequence.
  
  
  CONCLUSIONS
  Variations of Gd-DTPA transport through the blood-inner ear barriers induced by mitochondria toxin was visualized in guinea pigs using a clinical 3.0 T machine. IV injection of Gd-DTPA with 2 h of waiting time and imaging with 3D-FLAIR are optimal methods. The MRI observation of the inner ear in the animal model was translatable to patients with acute hearing loss, using an IV injection of Gd-DTPA at the routine dosage.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Changhai Hospital, Second Military Medical University, Shanghai, People's Republic of China. zoujinghb@hotmail.com
authors.forename: Jing
authors.initials: J
authors.lastname: Zou
authors.forename: Meng
authors.initials: M
authors.lastname: Li
authors.forename: Ya
authors.initials: Y
authors.lastname: Zhang
authors.forename: Guiliang
authors.initials: G
authors.lastname: Zheng
authors.forename: Donghui
authors.initials: D
authors.lastname: Chen
authors.forename: Shiyue
authors.initials: S
authors.lastname: Chen
authors.forename: Hongliang
authors.initials: H
authors.lastname: Zheng
mesh_terms: D000328:Adult; D000818:Animals; D001299:Audiometry; D001309:Auditory Threshold; D003051:Cochlea / Q000502:physiology; D003287:Contrast Media; D004247:DNA / Q000235:genetics; D053938:DNA Fragmentation; D007758:Ear, Inner / Q000378:metabolism* / Q000473:pathology*; D005260:Female; D019786:Gadolinium DTPA; D006168:Guinea Pigs; D006319:Hearing Loss, Sensorineural / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D009574:Nitro Compounds / Q000494:pharmacology*; D011422:Propionates / Q000494:pharmacology*; D014724:Vestibular Function Tests
chemical_list: D003287:Contrast Media; D009574:Nitro Compounds; D011422:Propionates; D004247:DNA; D019786:Gadolinium DTPA; C015392:3-nitropropionic acid