This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Radiology
Pseudo Poal doppler signal (continuous flow) in the hepatic vein in the setting of Budd chiari syndrome indicates: 
Select and explain. 
A. Paial IVC obstruction, B. Congenetal web in IVC, C. Poal vein thrombosis, D. Renal vein thrombosis
A: Paial IVC obstruction
Answer: A: Paial IVC obstruction 
Explanation: The normal blood flow in the IVC and hepatic veins is phasic in response to both the cardiac and respiratory cycles. In Budd chiari syndrome, flow in the IVC, hepatic veins, or both changes from phasic to absent, reversed, turbulent, or continuous. Continuous flow has been called a pseudo poal Doppler signal and appears to reflect either paial IVC obstruction or extrinsic IVC compression. Ref: J Ultrasound Med 2006; 25:373-379.