Computerized tomography of the temporal bone.

Computerized tomography is acquiring an increasingly important role in the radiographic assessment of the temporal bone. In the latest generation of CT scanners, spacial resolution has been reduced to 0.1 cu mm and slice thickness to 1.5 mm. The main advantages of computerized tomography in comparison to multidirectional tomography are the improved contrast of the images and above all the clear demonstration of soft tissue structures and masses within or adjacent to the temporal bone. The following three applications of computerized tomography will be discussed: 1. Evaluation of intratemporal soft tissue masses. Computerized tomography allows differentiation of fluid filled from solid masses and vascular tumors. 2. Assessment of lesions extending outside the temporal bone or into the temporal bone from adjacent structures. In these cases CT will demonstrate the temporal bone involvement and the presence and extension of the intra or extra cranial component of the lesion. 3. Study of the cerebellopontine angle. Computerized tomography with infusion and combined with pneumocisternography comprise the procedure of choice for the diagnosis of acoustic neuromas and other lesions occurring in this area.