抄録
This article reviews the basics of 3 dimensional computed tomography (3D-CT) and its application for non-neoplastic laryngeal disease. A wide variety of 3D-CT images can be obtained with the use of helical or multislice-helical CT scans. Images that are especially useful are derived from multiplanner reconstruction (MPR) and virtual endoscopy. The combination of both techniques enables us to obtain accurate anatomical information on the basis of virtual reality, and to help plan phonosurgery. Such anatomical information that can be comprehensively evaluated include : severity of vocal fold atrophy, location and extent of laryngeal stenosis, size of the laryngeal ventricle, relative location of vocal folds and arytenoid cartilage to the thyroid cartilage, and the height of the paralyzed vocal fold. These characteristics are not adequately evaluated with only the use of laryngoscope, even though it is a golden-standard for diagnosis of laryngeal disease. At present, there are several limitations with 3D-CT. 3D-image reconstruction takes much time and skill. The movement of vocal folds cannot be evaluated, since time resolution is insufficient. These limitations still prevent 3D-reconstruction to be a widely used modality. However, as a modality for preoperative evaluation of phonosurgery, 3D-reconstruction images are already in practical use, making up for laryngoscope shortcomings.
