Where is the common bile duct (CBD) located in relation to the head of the pancreas?

The common bile duct (CBD) is located posterior and lateral to the head of the pancreas. This anatomical relationship is significant because it helps in understanding the positioning of structures during abdominal imaging, particularly ultrasound.

The CBD runs close to the duodenum and the head of the pancreas, flowing through the hepatopancreatic ampulla (Ampulla of Vater) where it joins with the pancreatic duct before entering the duodenum. Recognizing that the CBD is posterior and lateral assists sonographers in correctly identifying these structures during an ultrasound examination, which can be crucial when evaluating conditions like biliary obstruction or pancreatitis.

Understanding this spatial relationship also aids in preventing misinterpretation of ultrasound images, ensuring the clarity of diagnosis.