[en] A prospective study was carried out in 100 patients with carcinoma of the digestive tract, in whom a CT-scan and a radionuclide scan were made prior to operation. The CT-scan and the radionuclide scan had the same degree of diagnostic reliability (about 80% correct diagnoses). Routine pre-operative CT or isotope scans do not in the authors' experience alter the surgical managemnent. From the in vitro investigation in which the liver is cut into the same slices as the computerized tomography, it appears that liver metastases larger than 3.5 cm diameter are always seen, while smaller metastases may be missed. The alkaline phosphatase and the gamma GT are no reliable estimations in establishing the diagnosis of liver metastases. (Auth.)