SEGMENTAL ENHANCEMENT OF THE COCHLEA ON CONTRAST-ENHANCED MR - CORRELATION WITH THE FREQUENCY OF HEARING-LOSS AND POSSIBLE SIGN OF PERILYMPHATIC FISTULA AND AUTOIMMUNE LABYRINTHITIS

PURPOSE: To relate the finding of selective enhancement of different t urns of the cochlea to the frequency range of the hearing loss measure d by audiogram. METHODS: Six patients aged 23 to 53 years, four men an d two women, who presented with sudden hearing loss and had segmental enhancement of different turns of the cochlea on contrast-enhanced MR imaging were included in this retrospective study. The patients were i maged on a 1.5 T MR imaging system using pre- and postcontrast axial T 1-weighted images and postcontrast coronal T1-weighted images through the temporal bone. RESULTS: The basal turn of the cochlea enhanced sel ectively in five of the six patients and the apical turn enhanced in t he sixth patient. All patients had sensorineural hearing loss. Three o f the patients with basal turn enhancement had predominantly high-freq uency hearing loss, whereas the patient with apical turn enhancement h ad predominantly low-frequency hearing loss. The two other patients wi th basal turn enhancement had complete hearing loss. Three patients ha d presumed autoimmune labyrinthitis. The other three patients had stro ng clinical and surgical evidence of a perilymphatic fistula. CONCLUSI ON: Contrast-enhanced MR imaging may demonstrate selective enhancement of different turns of the cochlea. In certain patients, the areas of enhancement may correlate with specific hearing loss in the frequencie s mapped by the enhancing segment. Enhancement of the cochlea may repr esent radiologic evidence of cochlear inflammation secondary to a peri lymphatic fistula.