[A three-dimensional reconstruction of the temporal bone by the helical scanning CT and its clinical application].

The current availability of 3 dimensional (3-D) imaging from Computed Tomography (CT) has yielded new anatomical information and pre-and postoperative evaluations. However, little discussion as to the 3-D structural image of the temporal bone has been reported because conventional CT does provide sufficient data to produce such images. The Helical scanning CT gathers continuous and multiple slice image data since it consists of an X-ray tube that continuously rotates around the patient while the patient moves continuously into the CT scanner. Thus, application of the Helical scanning CT has made it possible to reconstruct 3-D images of the minute and complicated structure of the temporal bone. We evaluated 3-D images from 9 typical cases, examined from February to October 1992. As a result, we found that the 3-D images reconstructed with this system are useful for evaluation of the postoperative state of tympanoplasty, the diagnosis of anomalies of the bony labyrinth, and examining the extent of bone destruction induced by trauma, cholesteatoma, etc.