Evaluation of Normal Epiglottis on Computed Tomography with Special Attention to Thickness

To our knowledge, this is the first study to investigate the thickness of the normal epiglottis on computed tomography (CT) in a Japanese population. The focus was on determining the thickness of a normal epiglottis, which could then serve as a reference in detecting abnormalities. We believe that this would facilitate diagnosing and determining the extent of cancerous invasion of the supraglottis and secondary invasion of the epiglottis. This retrospective study was based on a review of radiographic data in patient charts. Cervical CT scans obtained from 79 Japanese patients (44 men [55.7%] and 35 women [44.3%]; age range, 28-85 years; mean, 58.9 years) showing a normal epiglottis under laryngoscopy were evaluated. The thickness of the epiglottis was measured on CT scans and the results analyzed with the Student's t-test, an analysis of variance, and the Tukey-Kramer test. The epiglottis in men was significantly thicker than that in women (p<0.05). A statistically significant difference was observed in thickness depending on longitudinal height (p=<0.001). The thickness at the median was larger than that bilaterally in all patients (p=<0.001). No statistically significant difference was observed in thickness depending on side or age. The thickness of the normal epiglottis was established at each level. We believe that these data could serve as a reference in diagnosing and detecting abnormalities of the epiglottis.