Abstract
Hepatodiaphragmatic interposition of the colon (Chilaiditi syndrome) is considered to be rare conditions. The incidence of this condition is not exactly known in Japan. In order to know this incidence, we reviewed 116, 825 roentgenograms of chest mass survey, and detected 17 cases (0.015%) of Chilaiditi syndrome. The condition was observed in 6 males (0.016%) and 11 females (0.014%). The average age of the males was 68, 7, of the females 66.5. The frequency tends to increase with age, and no difference in two sexes was observed