title: Contrast-enhanced MR imaging of the endolymphatic sac in patients with sudden hearing loss.
abstract: Our objective was to evaluate the frequency of contrast enhancement of the endolymphatic sac in patients with sudden hearing loss. Forty consecutive patients with sudden sensorineural hearing loss (20 males and 20 females; age range 11-82 years), 40 age-matched control subjects, and 5 patients with Meniere's disease were examined using the same imaging protocol on a 1.5-T MR system. Pre- and post-contrast-enhanced T1-weighted 3D spoiled gradient-echo sequence (3D SPGR; TR/TE=23/10 ms, no. of excitations=1, flip angle=30 degrees) images were obtained using a voxel size of 0.6 x 0.7 x 0.8 mm(3). Contrast enhancement in the area of the endolymphatic sac was assessed by two radiologists, and the frequency of contrast enhancement was compared between the three study groups. Enhancement of the ipsilateral endolymphatic sac was observed in 30 of the 40 patients with sudden hearing loss (75%). Twenty of these 30 patients also showed enhancement on the contralateral side, and 1 patient showed enhancement only on the contralateral side. Only 1 of the 5 patients with Meniere's disease showed enhancement. Nine of the 40 control subjects (22.5%) showed enhancement (bilateral enhancement in 5 subjects, unilateral in 4). The frequency of enhancement in patients with sudden hearing loss was significantly higher than that in control subjects ( P<0.0001) or patients with Meniere's disease ( P<0.05). The frequency of contrast enhancement of the endolymphatic sac is significantly increased in patients with sudden hearing loss, but further study is necessary to clarify the relationship between this finding and the pathophysiology of sudden hearing loss.
authors.affiliation: Department of Radiology, Nagoya University School of Medicine, 65 Tsurumai-cho, Shouwa-ku, Nagoya 466-8550, Japan. naganawa@med.nagoya-u.ac.jp
authors.forename: Shinji
authors.initials: S
authors.lastname: Naganawa
authors.forename: Tokiko
authors.initials: T
authors.lastname: Koshikawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fukatsu
authors.forename: Takeo
authors.initials: T
authors.lastname: Ishigaki
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nakashima
authors.forename: Nobuyasu
authors.initials: N
authors.lastname: Ichinose
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D003287:Contrast Media; D004712:Endolymphatic Sac / Q000473:pathology*; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008575:Meniere Disease / Q000473:pathology; D008875:Middle Aged
chemical_list: D003287:Contrast Media