[Senile common bile duct. Radiological study].

From this study carried out under sufficiently strict conditions to analyze normal common bile ducts of the third to the tenth decade, with radio-geometric measurement redusurement reducing errors as far as possible, it appears that: a) there is no difference in the frequency and the density of opacification of the bile duct in young or elderly subjects, b) that the radiological diameter of the normal bile duct becomes enlarged with time, according to the formula: (see article) which may be considered in routine clinical practice as a true increase in diameter of about 1 mm per decade. The limits of true diameter of the bile duct, in our experience, were +/- 3 mm at 30 years to +/- 7 mm after 80 years.