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
A specific diagnostic criteria for Budd Chiari syndrome among the following is: 
Select and explain. 
A. Intrahepatic collaterals, B. Dilated paraumbilical vein, C. Post acoustic shadowing, D. None of the above
A: Intrahepatic collaterals
Answer: A: Intrahepatic collaterals 
Explanation: Intrahepatic collaterals are a specific diagnostic criterion for BCS. Paraumbilical vein is an exception, which is also seen in poal hypeension. Collaterals are either intrahepatic, which communicate with systemic vessels subcapsular collaterals or from an occluded hepatic vein to a non occluded hepatic vein or to the caudate lobe veins Ref: J Ultrasound Med 2006; 25:373-379.