Radiation dose in investigations of the large bowel. Comparison of radiation doses in examinations of the colon with double-contrast barium enema with the Welin modification and colonoscopy.

Because of the increasing and repeated application of colonoscopy and double-contrast barium enema with the Welin modification in connection with the checking of patients who have been treated for neoplastic polyps, we have found it valuable to examine the amount of radiation that the patients are exposed to in the two kinds of examinations. The radiation dose in the examination of the colon with the Welin modification (35 examinations) and at colonoscopy (114 examinations) was, on an average, 387 and 10 mSv, respectively. Since colonoscopy gives a possibility not only of diagnosis but also of treatment and also exposes the patients to 40 times less radiation than X-ray examination with the Welin modification, we recommend colonoscopy for diagnosis and treatment of neoplastic colonic polyps.