Establishing normal values for pediatric esophageal diameter on fluoroscopy.

Background: Standardized values for esophageal diameter on fluoroscopy have not been established. These values may help in the diagnosis of long-segment and diffuse esophageal narrowing, which can sometimes be subtle and difficult to diagnose.

Objective: Our objective was to establish normal values for esophageal diameter based on age for patients between 1 and 17 years old.

Materials and methods: Our retrospective study included 160 patients separated into eight groups by age with documented normal upper gastrointestinal fluoroscopic examination and normal esophageal biopsy. Three readers measured esophageal diameters in the three locations and two projections. Intra-class correlation coefficients were calculated in order to gauge reader measurement agreement. Student's t-tests were used to evaluate for statistically significant differences between male and female patients. Finally, overall means and 95% confidence intervals were calculated at each esophageal level by age group.

Results: Our readers demonstrated excellent measurement agreement (ICCs > 0.75). Three individual esophageal measurements varied between the biological sexes, but there was no reliable statistically significant difference. There was a linear upward trend in esophageal diameter with age. For each age group, the means, standard deviations, and 95% confidence intervals were calculated for esophageal diameter in each location and projection. Across all included ages, the mean esophageal diameter ranged from 11-21 mm on the anteroposterior projection and 8-17 mm on the lateral.

Conclusion: The provided ranges of normal esophageal diameters at each age and location in the pediatric population are quantitative metrics which can be used in the interpretation of fluoroscopic examinations. New reference values may lead to earlier diagnosis of esophageal pathology in the pediatric population.