Pre- and Postoperative Evaluations of Patients with Unilateral Vocal Fold Paralysis Using Ultra-high-resolution Computed Tomography

Abstract

Computed tomography is useful for diagnosing laryngeal trauma, the extension of laryngeal cancer and lymph node metastasis of carcinoma. Yumoto et al. reported that helical CT was useful for evaluating three-dimensional images of the laryngeal structure. Furthermore, they performed helical CT in patients with unilateral vocal fold paralysis in order to understand the laryngeal morphology. Hiramatsu et al. reported that this approach visualized the movement of the arytenoid cartilages on reconstruction imaging. The present study evaluated six patients with unilateral vocal fold paralysis whose voices improved after phonosurgery. Two patients underwent arytenoid adduction and thyroplasty typeI, two underwent only thyroplasty typeI, and two underwent injection surgery. The virtual endoscopic images reconstructed from ultrahigh-resolution CT (UHRCT) showed a gap in the posterior glottal region in the cases for whom preoperative evaluations using flexible laryngoscopy had been very difficult due to supraglottic hypertension. Postoperative changes in the arytenoid position were observed on three-dimensional images. UHRCT was shown to be effective for selecting the phonosurgery approach. This modality is a very important tool for determining which phonosurgical procedures to perform and for evaluating the postoperative change. We successfully evaluated the anatomical changes, glottal closure and position of arytenoid cartilages preand postoperatively using UHRCT.