Ultrasonography of the distal common bile duct: An easy-to-perform technique for better visualization

No standard ultrasonography (US) method exists for visualizing the distal common bile duct (CBD). The supine HD view is usually adopted for CBD evaluation, but duodenal or colonic gas shadowing can affect this view.

We developed and evaluated an easy-to-perform technique, the supine distal CBD view, applying the US protocol for the distal CBD evaluation. Five reviewers checked the visibility of the distal CBD and cystic duct, as well as each view's image quality and influencing factors.

The visibility of the distal CBD was enhanced on the supine distal CBD view (86.0%-94.6%) versus the supine hepatoduodenal view (40.8%-82.1%), with less variability among the reviewers. The image quality of the supine distal CBD view was superior to that of the supine HD view (2.52 ± 0.67 vs. 1.93 ± 0.86, respectively; p < 0.01). The depth of the distal CBD from the surface was significantly larger in the patients with nonvisible distal CBDs.

We present a user-friendly, easy-to-perform US view for locating and visualizing the distal CBD. With this technique, the distal CBD can be evaluated without changing a patient's position or increasing the duration of the procedure.