[Image processing of early gastric cancer cases]

Computer image processing was used to enhance gastric lesions in order to improve the detection of stomach cancer. Digitization was performed in 25 cases of early gastric cancer that had been confirmed surgically and pathologically. The image processing consisted of grey scale transformation, edge enhancement (Sobel operator), and high-pass filtering (unsharp masking). Gery scale transformation improved image quality for the detection of gastric lesions. The Sobel operator enhanced linear and curved margins, and consequently, suppressed the rest. High-pass filtering with unsharp masking was superior to visualization of the texture pattern on the mucosa. Eight of 10 small lesions (less than 2.0 cm) were successfully demonstrated. However, the detection of two lesions in the antrum, was difficult even with the aid of image enhancement. In the other 15 lesions (more than 2.0 cm), the tumor surface pattern and margin between the tumor and non-pathological mucosa were clearly visualized. Image processing was considered to contribute to the detection of small early gastric cancer lesions by enhancing the pathological lesions.