Computerized axial tomography in the assessment of thyroid cartilage invasion by laryngeal carcinoma: a prospective...

The purpose of this study was to assess the value of computerized axial tomography (CAT) in canine larynges that exhibit controlled surgical defects, and in 18 patients with biopsy-proved epidermoid carcinoma of the larynx who were studied prospectively. Five canine larynges with sequential surgical defects of 0 mm, 5 mm, 10 mm, and 15 mm were studied by CAT in order to evaluate our ability to identify defects in the thyroid cartilage. A 5-mm collimator with overlapping sections at 3-mm intervals and a 13-mm collimator with 5-mm overlapping sections were both used for each stage of the experiment. Results show significantly improved resolution with the 5-mm collimator compared with the 13-mm unit. In the human study group, results demonstrated excellent (100%) soft-tissue tumor site correlation. It appears from this study that we still lack a highly reliable radiographic technique for evaluating preoperatively with accuracy the integrity of the thyroid cartilage in the patient with carcinoma of the larynx.