[Radiation dosage and clinical value of conventional tomography and high resolution computerized tomography of the nose and ear].

Hypocycloidal (frontal and temporal) tomography of the base of the skull is compared with high resolution computed tomography (HR-CT) with respect to dose and clinical usefulness. In most cases HR-CT is indicated because of its better density resolution in comparison with conventional hypocycloidal tomography. As the X-ray beam is directed at the slice plane the dosage is noticeably less than when using conventional tomography. Slice thickness depends on the required geometric resolution. This is an additional factor in radiation protection.