[Utility of SCG (screening colonography) and combined sigmoidoscopy-SCG in thorough physical checkups]

Given the increasing incidence of colon cancer in recent years, it is important to establish a diagnostic system for early detection and introduce it into clinical practice. A double contrast examination that uses a disposable tip and tube with an enema reservoir filled with 200 ml of 60 w/v% barium sulfate, known as SCG (screening colonography) was used in this study. In order to assess its utility SCG was performed on 1,554 patients, and 2,004 patients were examined by a within 24 hours combination of sigmoidoscopy and SCG by way of screening for colon cancer. Given the brief duration of SCG, which ranged from 10 to 13 min in most patients in the study, the efficiency of the examinations was considered to be rather high. Furthermore, the barium reached the cecum in as many as 98.7% of the patients. Overall, SCG proved to have an excellent diagnostic capability. Sigmoidoscopy-SCG, on the other hand, detected colon cancer in 114 patients (5.7%) and colon polyps in 658 patients (32.8%). The rates of detection of colon cancers and polyps were higher in the patients who tested positive in immunological fecal examinations for occult blood. Judging from our results, it may be said that for many patients receiving thorough physical checkups to screen for colon cancer, our system will provide for efficient screening whereby patients are first examined for fecal occult blood and those who test positive undergo sigmoidoscopy and SCG within the same day.