[Multiplanar angulated 2D reconstruction. A new CT technique for imaging the facial nerve canal].

For imaging the facial canal in its tympanic and mastoid segments, a new technique was developed with high-resolution computed tomography (HRCT). This method is based on comparative anatomical studies and makes it possible to depict the course of the facial canal, especially in malformations of the middle ear and in cases of fractures, tumors and cholesteatomas. A longitudinal scan of the petrous part of the temporal bone is obtained by reconstruction based on primary axial CT-standards. In these longitudinal scans the facial canal is shown both in its tympanic and mastoidal segment. For longitudinal reconstruction the scan is orientated through the anterior margin of the carotid canal and petrous pyramid. For evaluating the facial canal in this study, the lateral semicircular canal and stylomastoid foramen are sure landmarks. The sensitivity for evaluating the tympanic segment of the facial canal is 100%. This new technique should be applied in cases in which the exact course of the facial canal must be known preoperatively.