The width of the common bile duct in relation to age and stone disease. An ultrasonographic study.

The common bile duct (CBD) was measured in 600 ultrasound studies. In normal patients the mean width of the CBD increased from 2.8 mm in the age group 20 years or younger to 4.1 mm in patients 71 years of age or older. The mean width of the CBD for all age groups in normal cases was 3.4 (range 2 to 11 mm). In presence of cholelithiasis the mean width of the CBD was 4.5 mm (range 2 to 15 mm). There was no further increase of the CBD after cholecystectomy (mean width 4.6 mm, range 2 to 12 mm). The CBD in patients with hepatocellular disease was wider than normals (mean 4.4 mm) and markedly increased in patients with pancreatic disease (mean 6.2 mm, range 2 to 21 mm) due to obstruction in several cases.