[A roentgenological study of Chilaiditi's syndrome].
The studies on Chilaiditi's syndrome reported in Japan have been mostly case reports on one or two cases. There have been studies on 356 cases in all. We have selected 262 cases with detailed data takes from the above 356 cases, together with 116 further cases of Chilaiditi's syndrome that we have encountered up to 1990, i.e. since our previous report in 1965. We also investigated roentgenograms, complications, interpositions and age distribution. The syndrome was mostly found in middle-aged and elderly patients of 50 years or older. More male patients were involved than female, however this is not necessarily true if the total number of patients under study is taken into account. Among the complications, gastric and duodenal diseases (ulcer and carcinoma) were most frequently found, accounting for 20.6% of the total reported cases in Japan. In our own study, the percentage was as high as 33.7% because radiography with contrast medium was positively conducted on the digestive tract. Of the interpositions, the colon accounted for 93.1% of our cases, and 72.9% of the total reported cases in Japan. The involved sites were mostly the right hepatic flexure of the colon and the transverse colon. From the reports by other researchers in the past and our data from 1965, 1975 and 1977, it appears that the incidence is about 0.003-0.03%. There were no subjective symptom specific to Chlaiditi's syndrome, and there may be various factors accounting for the occurrence of the syndrome. The symptoms were primarily based on the underlying diseases, and Chilaiditi's syndrome merely indicates the condition where the digestive tract interposes between the diaphragm and liver. Therefore, we regard this as a radiographical sign rather than a syndrome, and we propose that this should be called "Chilaiditi's sign". We also emphasize that the digestive tract must be strictly examined if this sign is to be noted.