This is a report on the precision controlled gastric mass screenings conducted under the sponsorship of the Welfare Federation of Agricultural Cooperatives in Nagano Prefecture and the assessment test using some samples of radiographic stomach images.
Physicians and x-ray technicians participated in the test and interpreted in their own ways the radiographs of 30 healthy cases and 20 cases of cancer of the stomach. Experienced physicians and technicians made better scores on the test than those less experienced in reading radiographs. Physicians read a little better that technicians in checkups of different parts regardless of years of experience, but the difference was not significant. In terms of FP and FN percentages (?), physicians scored 40.5% and 20.8% on the first tryout, and 34.0% and 29.0% on the second tryout.
The 1988 mass screening found 67.4% of cancer in antral and angular areas and 23.8% on the lesser curvature side of the angular area.
Grade 5 means that “No doubt about the existence of cancerous lesions.” In the 1983 screening, 25% of the grade 5 cases turned out to be nothing wrong upon close examination. The figure went down to 5.9% in the 1988.