Radiological examinations and diagnosis of labyrinthitis

OBJECTIVE To investigate the radiological findings of labyrinthitis and evaluate the diagnosis value of HRCT and MRI. METHODS The HRCT and MR images of 27 cases ( 31 ears) with labyrinthitis,suggested by clinical examinations and abnormal changes on images coexisting,were studied. RESULTS In the 22 ears which underwent HRCT examinations,6 ears showed increase of the density of one or more structures of inner ear,8 ears showed increase of the density of structure as well as change of the shape of the inner ear,1 ear showed change of the shape only. Labyrinth inner cavity appeared local or total sclerosis and disappearance in 7 ears. Among the 22 ears,there was bony incompleteness in 4 besides the changes mentioned above. In the 9 ears which accepted HRCT and MR scanning,7 ears showed abnormal changes of different degree in the inner ear on HRCT images and the other 2 appeared normal. On MR images,all 9 ears showed decrease or disappearance of the signal of T2WI in one or more structures of membranous labyrinth. Among the 6 ears which performed contrast scanning,markedly enhancement was seen in 4 and no enhancement in 2 ears. Of all the 31 ears,cochlea was involved in 30,of which only basal turn involved in 5,upper and second turns in 2 and all turns in 23,semicircular canal involved in 26,vestibule in 20,oval window in 18 and round window in 19. CONCLUSION HRCT can demonstrate the abnormal changes of bony labyrinth,and MRI is helpful to detect the changes of labyrinth inner cavity. They have important value in the detection and diagnosis of labyrinthitis.