Characteristic MR findings suggesting presumed labyrinthine hemorrhage.

OBJECTIVES: To evaluate the magnetic resonance imaging (MRI) findings of labyrinthine hemorrhage as a cause of sudden sensorineural hearing loss (SSNHL). METHODS: MRI scans of 59 patients with SSNHL were retrospectively analyzed and compared to clinical features and audiometry data. MR images included pre-enhanced T1-weighted, 3D FLAIR volume isometric turbo spin-echo acquisition (VISTA), post-enhanced T1-weighted and 4-h-delayed enhanced FLAIR VISTA, and 3D thin-section proton density-weighted images. RESULTS: High labyrinth signals were seen on pre-enhanced T1-weighted and 3D FLAIR VISTA images with no enhancement for 6 of 59 (10.2%) patients with SSNHL. In these six patients with presumed inner-ear hemorrhage, high signal intensity was seen in the endolymphatic and perilymphatic portions of the labyrinth on T1-weighted and 3D FLAIR VISTA images. In patients with SSNHL with nonhemorrhagic causes such as vestibular schwannoma or labyrinthitis, high signal or labyrinthine enhancement was seen only in the perilymphatic portion of the labyrinth on pre- or post-enhanced 3D FLAIR VISTA images. CONCLUSIONS: MRI using pre-enhanced T1-weighted, 3D FLAIR VISTA, and post-enhanced T1-weighted, 4-h delayed enhanced FLAIR VISTA images is able to identify labyrinthine hemorrhage as the cause of SSNHL. High signals in both the endolymphatic and perilymphatic portions of the labyrinth on pre- or post-enhanced 3D FLAIR VISTA images without enhancement indicate labyrinthine hemorrhage.

Quantitative Analysis of the Facial Nerve Using Contrast-Enhanced Three Dimensional FLAIR-VISTA Imaging in Pediatric Bell's Palsy

PURPOSE: To evaluate the usefulness of quantitative analysis of the facial nerve using contrast-enhanced three-dimensional (CE 3D) fluid-attenuated inversion recovery-volume isotopic turbo spin echo acquisition (FLAIR-VISTA) for the diagnosis of Bell's palsy in pediatric patients. MATERIALS AND METHODS: Twelve patients (24 nerves) with unilateral acute facial nerve palsy underwent MRI from March 2014 through March 2015. The unaffected sides were included as a control group. First, for quantitative analysis, the signal intensity (SI) and relative SI (RSI) for canalicular, labyrinthine, geniculate ganglion, tympanic, and mastoid segments of the facial nerve on CE 3D FLAIR images were measured using regions of interest (ROI). Second, CE 3D FLAIR and CE T1-SE images were analyzed to compare their diagnostic performance by visual assessment (VA). The sensitivity, specificity, and accuracy of RSI measurement and VA were compared. RESULTS: The absolute SI of canalicular and mastoid segments and the sum of the five mean SI (total SI) were higher in the palsy group than in the control group, but with no significant differences. The RSI of the canalicular segment and the total SI were significantly correlated with the symptomatic side (P = 0.028 and 0.015). In 11/12 (91.6%) patients, the RSI of total SI resulted in accurate detection of the affected side. The sensitivity, specificity, and accuracy for detecting Bell's palsy were higher with RSI measurement than with VA of CE 3D FLAIR images, while those with VA of CE T1-SE images were higher than those with VA of CE 3D FLAIR images. CONCLUSION: Quantitative analysis of the facial nerve using CE 3D FLAIR imaging can be useful for increasing the diagnostic performance in children with Bell's palsy when difficult to diagnose using VA alone. With regard to VA, the diagnostic performance of CE T1-SE imaging is superior to that of CE 3D FLAIR imaging in children. Further studies including larger populations are necessary.