목적: Pneumolabyrinth, the presence of air within the labyrinth, is an extremely rare radiological finding after temporal bone trauma. The purpose of this study is to evaluate the radiological features of pneumolabyrinth in patients with temporal bone fracture (TBFx). 방법:Temporal bone computed tomography (TBCT) of 401 patients with TBFx or skull base fracture (SBFx) from January 2004 to July 2014 were retrospectively reviewed. TBCT was performed using a high- resolution CT scanner (Somatom Sensation 62, Siemens Medial Solutions, Malvern, Pa). It was performed with the following parameters 0.6mm section thickness, a 512 x 512 matrix, 0.1 mm2 pixel size. In order to differentiate otic capsule sparing and disrupting fracture, we adjusted the TBCT window setting as comprising window level (L) to 600 Hounsfield unit (HU) and window width (W) to 2000 HU. The HU was checked using the Marosis m-view systems region of interest (ROI) function to confirm the air density. When the HU was below - 800, we considered the lesion as air density. 결과:Only 5 of a total 401 patients were diagnosed as a pneumolabyrinth. Although all of these 5 patients had a otic capsule disrupting fracture, pneumolabyrinth was detected in less than 1% of otic capsule disrupting fractures (0.6%, 5/83) and there is no patient with pneumolabyrinth in otic capsule sparing fractures (0%, 0/318). The mean areas of the air density were 5.38 mm2 in axial scan and 6.57 mm2 in coronal scan. Locations of the pneumolabyrinth were detected at the vestibule in all 5 cases and there were 2 cases that showed air densities at the semicircular canal or cochlea simultaneously. 결론:Pneumolabyrinth is an extremely rare condition even in otic capsule disrupting fracture. To detect the pneumolabyrinth, imaging mode of TBCT should be rearranged with high quality and size and HU of lesion should be considered to rule out technique- related artifact (aliasing artifact).