Sonographic assessment of the epiglottis

The ideal diagnostic test for the diagnosis of epiglottitis would be simple, rapid, noninvasive, and highly accurate, performed at the bedside, and would not use ionizing radiation. The purpose of this study was to assess the utility of ultrasound to image the epiglottis and to determine the range of normal epiglottis diameter for men and women.

This was a prospective study of a convenience sample of 100 subjects between the ages of 18 and 50 years who had no known acute or chronic laryngeal diseases or surgeries. The anterior neck of each subject was scanned in both the long and short axis with a 5-10 MHz linear transducer. Sonographically, the epiglottis appeared as a curvilinear, hypoechoic structure with an echogenic pre-epiglottic space. The sonographic appearance of the epiglottis and the pre-epiglottic space were recorded and anteroposterior measurements of the epiglottis just distal to the hyoid bone were made. Comparisons between men and women were performed with use of a Student's t-test. Pearson's correlation analysis was performed to evaluate the relationship between subject height and epiglottic size.

The epiglottis was visualized in all 100 subjects including 62 women and 38 men. The average patient age was 35.2 +/- 8.1 years. The epiglottic thickness was 2.39 +/- 0.15 mm. This was greater in men (2.49 +/- 0.13 mm) than in women (2.34 +/- 0.13 mm) (p < 0.001). There was moderate correlation between height and epiglottic thickness (R = 0.48). However, when this was analyzed separately for men and women, there was no significant correlation between epiglottic thickness and height.

Bedside ultrasonography is easy to perform and can accurately evaluate the epiglottis. Further analysis should include patients with known epiglottic disease to assess the utility of this technique to detect pathologic enlargement.