CT in carcinoma of the larynx and pyriform sinus: value of phonation scans.

The structural and functional information obtained from CT performed during quiet breathing and phonation of the letter E was investigated in 25 patients with carcinoma of the larynx or pyriform sinus. Significant additional information was obtained from the phonation scans in all patients. In 16 patients, vocal cord dysfunction was found on the phonation scans. In 14 patients, phonation CT demonstrated an abnormal aryepiglottic fold better than CT during quiet breathing. A pyriform sinus was distorted or displaced in 11 patients and CT during phonation was more accurate than laryngoscopy or CT during quiet breathing in detecting abnormalities deep to this region. CT scans were the most accurate method of detecting tumor extension into the subglottic space, and into the preepiglottic space; each extension was seen in seven patients. Thyroid cartilage destruction was detected only by CT in six patients. CT scans during phonation should be an integral part of laryngeal CT and in conjunction with laryngoscopy could possibly replace laryngography for the evaluation of patients with laryngeal carcinoma.