Objective To study the usefulness of oral contrast-enhanced helical CT cholangiography in the diagnosis and treatment for bile duct diseases.Methods 18 cases of suspected bile duct diseases were studied. The dose of iopanoic acid was 6.0 gram (n=5), 3.0 gram (n=10) and 1.0 gram (n=3). CT scan was performed 12~14 h after administration. Reformatted 2D and 3D MIP images were got from axial source images. The opacified degree of bile duct was described as no opacification, light opacification, well opacification or overopacification . The findings of CT chonlangiography were compared with pathological and/or clinical results . Results (1) The dose ofiopanoic acid could effect the opacified degree of bile duct. It should be more than 6.0 gram to investigate intrahepatic bile duct, and 3.0gram should be enough to investigate extrahepatic bile duct; (2) Intra- and extrahepatic bile duct anatomy could be display clearly,especially the extrahepatic duct. Function of bile duct system, relations between lesion and bile duct, and the obstructed degree of bile duct could be revealed too. Sensitivity was 80% in diagnosis of negative gallstone and gallpolypus . Sensitivity was 88.9% and specificity was 100% in diagnosis of negative gall-stone in general bile duct ; (3) 2D and 3D MIP reconstructions displayed the spatiality of bile duct better.Conclusion Oral contrast-enhanced helical CT cholangiography is feasible and noninvasive. It is a well method in revealling the bile duct anatomy and diagnosing the bile duct lesions, and is useful for bile duct operations.

Objective To investigate the radiation and radioprotection in bedside digital radiography. Methods 650 cases undergoing X-ray examination in sugical wards are involved. Results The patients' X-ray radiation dose is 3.12~7.68 mGR. Conclusion To avoid unnecessary radiation, radioprotection should be emphasized when improving images' quality.