Quantitative endoscopy: precise computerized measurement of metaplastic epithelial surface area in Barrett's esophagus.

BACKGROUND/AIMS: The inability to precisely measure the area of Barrett's metaplasia has impaired the study of its natural history and response to therapy. This study used a novel computer program that creates two-dimensional maps of the esophagus allowing for calculation of the area of Barrett's metaplasia.

METHODS

Endoscopic photographs of Barrett's models and patients were obtained by independent endoscopists. The program transformed the photographs into maps, and the area of Barrett's metaplasia was calculated.

RESULTS

Using models, calculated areas correlated with actual areas (r = 0.96) with an overall error of 5.2%. Color, size, shape, diameter of the model, or endoscopist's experience did not affect the accuracy. Accuracy did improve by decreasing the interval between photographs from 4 cm (10.0% error) to 2 cm (4.8% error). In patients, area calculations from maps created by independent technicians correlated precisely (r = 0.99) at 1-cm (n = 22) and 2-cm (n = 40) intervals. Independent endoscopists correlated precisely in producing photographs for map construction (r = 0.99; n = 20).

CONCLUSIONS

This novel computer technology produces two-dimensional maps of Barrett's metaplasia that can be used to accurately calculate area. Minimal interobserver variability in obtaining photographs is found.