Clinical feasibility of the new technique of functional 3D laryngeal CT

Conclusions. Functional 3D laryngeal CT (F3DLxCT) is an informative tool for visualizing the active changes in length, tension and mass of the vocal folds for pitch control. Furthermore, volume defects and level differences of paralyzed vocal folds are easily detectable with this new technique. Objective. To evaluate the clinical feasibility of F3DLxCT images, which can provide clear coronal images of the vocal fold in each anteroposterior direction during phonation and in the resting state. Material and methods. FLxCT images were reconstructed to three dimensions to visualize laryngeal motion. FLxCT was performed in four normal controls and in four patients with unilateral vocal fold paralysis in the resting state and during phonation with three vowel sounds of different pitch. 3D images were reconstructed with segmentation and a surface-rendering algorithm on a PC, using the DICOM file of axial images. Results. The dynamic vocal fold 3D image during phonation could visualize that the thickness and volume were decreased in relatively to the pitch increase. Typical subglottic shoulder-like image formation and ventricular widening were noted with the high-pitch tone.