Final answer:
Percutaneous transhepatic cholangiography (PTC) is a diagnostic procedure to image the bile ducts by inserting a needle through the skin and liver to inject a contrast dye, followed by X-ray imaging. It is used to diagnose obstructions or abnormalities in the biliary tree and differs from the less invasive ERCP, which uses an endoscope passed through the digestive tract.
Step-by-step explanation:
Percutaneous transhepatic cholangiography (PTC) is a radiologic procedure used to visualize the anatomy and pathology of the bile ducts. It involves the insertion of a thin needle through the skin and liver tissue directly into the bile ducts within the liver. A contrast dye is then introduced through the needle, and X-ray images are taken to show the structure and patency of the biliary tree.This procedure is often performed in patients who may have an obstruction in the bile ducts, such as from gallstones or tumors. It is also used when non-invasive imaging techniques, like magnetic resonance cholangiopancreatography (MRCP) or ultrasound, are inconclusive or not possible. PTC may accompany other interventions such as bile drain placement or to help in planning surgery for bile duct obstructions.It's different from endoscopic retrograde cholangiopancreatography (ERCP), which is less invasive and entails the introduction of an endoscope through the mouth, down the stomach, and into the small intestine to inject dye into the bile and pancreatic ducts.