AXIAL HRCT, 2-DIMENSIONAL AND MAXIMUM INTENSITY PROJECTION RECONSTRUCTIONS IN TEMPORAL BONE-LESIONS

Axial and coronal high resolution computer tomography (HRCT) of the te mporal bone is an important imaging technique to evaluate hearing loss . However the acquisition of the coronal imaging proves uncomfortable to the patient and is not always technically possible in old and ill p atients. Clinical diagnoses of chronic otitis media, mastoiditis, chol esteatoma and cochlear otosclerosis in 10 patients were studied on a t hird generation CT scanner. Axial 1 mm HRCT slices were acquired and t he images were transferred to an Advantage Windows workstation where t wo-dimensional (2D) multiplanar and sagittal maximum intensity project ion (MIP) reformations were performed. Our aim was to study the abilit y of this technique to identify several small structures of the tempor al bone in Various diseases. In all cases the finer structures of the temporal bone were identified in axial HRCT images. The tegmen tympani , atticus and the cochlea were best seen in the 2D coronal reconstruct ions. The aditus ad antrum, facial canal, vestibule and the semicircul ar canals were best seen on 2D sagittal reconstructions. The joints be tween the bony ossicles of the middle ear was best seen in the sagitta l MIP reconstructions. Our results suggest that axial HRCT, 2D multipl anar and MIP reconstructions of the temporal bone produce images with sufficient diagnostic quality in patients with hearing loss.