3. Endoscopic retrograde cholangiography and Percutaneous transhepatic cholangiography
Endoscopic retrograde cholangiography (ERC) and Percutaneous transhepatic cholangiography (PTC) are two critical diagnostic techniques used to diagnose cholestasis. ERC is a procedure where small probes are inserted into the pancreatic and biliary ducts, which are then used to inject a contrast dye for visualization. On the other hand, PTC is a more aggressive procedure where a contrast dye is injected directly into the bile ducts using a needle. These procedures allow for visualizing any blockages or abnormalities of the bile ducts and are essential for diagnosing cholestasis.
In the case of ERC, a catheter is passed into the pancreatic and biliary ducts, and a contrast dye is injected. This dye helps in outlining the ductal structure and any blockages or abnormalities. For PTC, the contrast dye is injected directly into the bile ducts using a needle, allowing for more detailed visualization of the bile ducts. This allows the doctor to determine if a blockage, narrowing, or abnormal structure exists.