Ultrasonographic dimensions of the common bile duct in Chinese children: results of 343 cases.

Background: At present, the diagnostic criteria of congenital cholangiectasis are still vague.

Purpose: The aim of this study was to assess the diameter references of the common bile duct (CBD) in pediatric population in different age groups with ultrasound.

Methods: The diameter of the common bile duct was measured with ultrasound in 343 Chinese Han children aged 1 day to 14 years (mean: 3.2 years, median: 2.8 years) who were all free of hepatic and biliary tract disease. The ultrasound records, gender, and age were collected for reviewed analysis.

Results: A total of 343 children were included, and the CBD was clearly detected in 322 cases (93.9%). The mean diameter of this population was 1.58 ± 0.70 mm. (ranging from 0.4 to 4.4mm). Spearman correlation analysis showed that the diameter of CBD was positively associated with age (r=0.573, P<0.001). The percentile method demonstrated that the diameter references of CBD was as follows: ≤ 1 years: ≤ 2.26 mm; ≤ 4 years: ≤ 2.99 mm; ≤ 7 years: ≤ 3.03 mm; and ≤ 14 years: ≤ 4.10mm.

Conclusions: There was a close correlation between CBD width and the age. The range of CBD widths in each age group will be helpful in the diagnosis of biliary dilatation in childhood.