The Association of Radiologists under the umbrella of the Hokkaido Prefectural Federation of Agricultural Cooperatives for Health and Welfare (Hokkaido Koseiren) set up in 2003 a committee with the aim of improving the accuracy of mass health examinations. Recently, the committee reviewed the results of abdominal examinations by sonography performed at the eight hospitals affiliated with the Koseiren during fiscal 2006 that ended March 31, 2007. Of those individuals who underwent thorough health checkups, 91.3% had their abdomen examined by ultrasound. Something anomalous was detected in 68.1% of the examinees and 4.5% needed to undergo closer checkups, the rate of response to which was 74.5%. The detection ratio of cancer by ultrasonography was worked out at 0.048%. The ratio of patients requiring a closer exam to the total and the cancer detection ratio varied widely from hospital to hospital. The wide dispersion was ascribable to the difference in the standard of judgment for indicating closer examinations and the difference in the number of examinees so far as the cancer detection ratio was concerned, from hospital to hospital. A look at the primary findings of anomalies revealed that fatty liver topped the list accounting for 27.4% followed by cholelithiasis with 3.6%. From this, we realized that the abdominal examinations by sonography served to detect cancer and lifestyle-induced health problems as well. Organ-wise, the cancer cases found during the period from 1998 to 2009 broke down as follows: kidney (79 cases), liver (40 cases), pancreas (30 cases), gall bladder (24 cases), others (8 cases) and spleen (none). The cancer detection ratio per year ranged from 0.03 to 0.05% during the period.