Application of 4D-CT Scanning in Differential Diagnosis of Arytenoid Subluxation and Vocal Fold Paralysis

Abstract

To differentiate arytenoid subluxation and vocal fold paralysis by CT cine mode scanning combined with three-dimensional (3D) reconstruction image. Seventy-six patients with suspected vocal fold dyskinesia were collected. All patients were examined being asked to inhale deeply and then make "Yi" sound continuously during CT scanning with cine mode. The optimal maximum opening and minimum closing phases of glottis were selected and 3D reconstruction images were performed. The length of vocal fold, the width of glottis, and the subglottal convergence angle, anteversion angle, elevation angle, valgus angle, and varus angle of cricoarytenoid joints were measured. Vocal fold deformation was divided into three types: type I, type II, and type III. Kappa test was used to compare the consistency between CT diagnosis and clinical diagnosis. Single-factor analysis of variance was used to analyze the statistical differences among arytenoid subluxation, vocal fold paralysis, and normal vocal fold. There was high consistency between CT diagnosis and clinical diagnosis (k=0.731, P < 0.05), as well as significant differences in the opening width of glottis between type I and type III, the valgus and varus angles of cricoarytenoid joints between type I and type II or type III, and the subglottal convergence angles among the three types of vocal fold deformation. CT scanning with cine mode combined with 3D reconstruction can display the changes of larynx structures in vocal fold dyskinesia, and can be used for the differential diagnosis of arytenoid cartilage subluxation and vocal fold paralysis.