Screening Technique Helps Diagnose Enteric Lesions

A computer-assisted screening technique discriminates among thousands of capsule endoscopy (CE) images obtained for diagnosing enteric lesions.

Capsule endoscopy, using what is practically a microcamera, can acquire 40-60 thousand images of the gastrointestinal (GI) tract, even though the number of images obtained for lesions is less than 500 for most patients. However, the CE reader (technician) has to scan thousands of the images, one by one, because the reader cannot establish beforehand in which of the images the lesions will be seen. This results in a large burden on the CE reader's eyes, stamina, and time.

Professor Jun-Chao Wu, M.D. and Dr. T. Gan from the West China Hospital of the Sichuan University (Chengdu, China) developed a diagnostic technique in which the kind of images screened by image-processing software (IPS) is based on the characteristic colors and contours of the lesions. This technique deselects a large number of normal images from the original set of images and keeps only 10%-15% for analysis.

Sensitivity in the screening of the commonly encountered enteric lesions by IPS varied from 42.9-91.2%, with a mean of 74.2%, compared with results obtained by the CE readers. Specificity and accuracy rates were still low, and the images for the rarely encountered lesions were difficult to differentiate from the normal images. However, a large number of normal images were excluded, and the mean reading time decreased from five hours down to one.

The computer-aided diagnosis technique trial was described in the December 7, 2008 issue of the World Journal of Gastroenterology (WJG).