Question

CT scan of the abdomen shows a vascular structure that branches as it enters the liver. Identify the structure.

• A. SVC
• B. IVC
• C. Portal vein
• D. Splenic vein

Hint:

Which vessel divides into right and left branches at the porta hepatis to supply the Couinaud segments?

Answer 1

The Correct Option is C

Step 1: The vessel entering the liver and dividing into right and left branches at the porta hepatis is the portal vein. The portal vein carries blood from the gastrointestinal tract, gall bladder, pancreas, and spleen to the liver, so it is the dominant branching inflow vessel seen on a CT of the abdomen.
Step 2: On entering the liver, the portal vein divides and supplies the Couinaud segments, which are defined by their vascular supply. This branching pattern into the hepatic parenchyma is the classic radiological appearance described in this question.
Step 3: Why the distractors are wrong: the SVC drains the upper body into the right atrium and never enters the liver. The IVC runs in a groove on the posterior surface of the liver and receives the hepatic veins; it does not branch into the liver. The splenic vein joins the superior mesenteric vein to form the portal vein and is a tributary, not the branching structure entering the liver.
Step 4: Note that the caudate lobe (segment I) is unique, receiving supply from both left and right portal branches and draining directly into the IVC. The correct answer is the portal vein.