The elusive gallbladder

30 minute of the hepatobiliary study, pre-CCK administration. The question was raised if this was the gallbladder or distended duct.  An additional image was obtained in the LAO view to further determine if this was the gallbladder..

After review of the LAO view (5 minute acquisition time) it was decided that this looked like the gallbladder, so the CCK study could begin.

Using the same position as the previous LAO image, the computer was set-up for CCK infusion and  acquisition. As the study was started it was noted that the gallbladder appeared.

In review the structure that was originally thought to be the gallbladder was most likely distended common bile duct.

Thanks to Larisa Levran

Dilated Common Bile Duct

When blockages can occur in the  bile ducts, they can become dilated. These blockages can be associated with gall stones or cholangiocarcinomas. Dilated ducts are also common in patients following cholecystecomy, which may increase in size over time. However this is usually of no significance by itself, unless there are other findings such as pancreatitis or elevated liver functions.

The non-contrast CT images above demonstrated an incidental finding of dilated common bile duct (yellow outline) in a female with a history of cholecystectomy. Hepatobiliary scan requested to determine duct patency.

4 mCi Tc Choletec was administered intravenously and imaging was completed in the anterior projection for 1 hour. The images demonstrate normal  passage of the Tc Choletec through the common bile duct and into the small intestine, demonstrating no blockage in the common bile duct.

Reference image - Gallbladder (green) liver (orange) kidneys (light blue) aorta (red) inferior vena cava (blue)

Reference: Are dilating bile ducts a cause for concern?  ML Wilkinson, Gut 1999;45:637-638