[Detailed structural analysis of the petrous bone using high-resolution thin-layer computerized tomography. 1. Sensitivity of substructural demonstration using a standardized study technic].

High-resolution CT, using fine sections, is a valuable method for radiological examination of the petrous bone. A standardized method of examination using the orbitomeatal and coronary plane is adequate for detailed screening of the petrous bone and shows almost all structures with high accuracy. The sensitivity of the method for showing 35 sub-structures of the inner and middle ear was investigated by examining 40 petrous bones which were normal clinically and radiologically, using the orbito-meatal and coronary planes. The radiation dose to the lens is less than from pluri-directional tomography. For special problems and for demonstrating very small structures, cuts may have to be performed in other planes, suitable for the required topography.