Determination of Diameter and Angulation of the Normal Common Bile Duct using Multidetector Computed Tomography

Background/Aims: Common bile duct stones are associated with the extent of dilation of the common bile duct as well as its angulation. Multidetector computed tomography (MD CT) has a good resolution for the definition of the anatomical features of the common bile duct. Methods: The multiplanar reformation images of 398 patients that underwent multidetector CT for the diagnosis of disorders not related to the bile duct were examined. The diameter and angulation were categorized by gender and age. Results: The average diameter and angulation of the common bile duct was 6.7 mm and 132.6 degrees. There was a statistically significant correlation between age and the common bile duct diameter. The Pearson correlation analysis for age and diameter resulted in a value of 0.415 (p<0.001). And the common bile duct (CBD) diameter in people older than 51 years of age showed a significant difference compared to the subjects younger than 50 years of age (p<0.01). However, the degree of angulation has no correlation with age. Conclusions: We suggest that CBD diameters in patients more than 50 years of age can be more than 7 mm and be within normal limits. (Gut and Liver 2009;3. 306-310)