A 45 year old woman has had severe epigastric and right hypochondrial pain for a few hours. She has a normal CBC, serum ALP is raised, normal transaminase. 3 months ago she had a cholecystectomy done. What is the most appropriate investigation?

The key is C. MRCP. [Post operative US of abdomen does not give good result for hepatobiliary system. ERCP is invasive procedure and it has its considerable complications like cholangitis, injury, pancreatitis etc. Among given options MRCP is most appropriate. We shall go for ERCP after making the diagnosis confirm. For this MRCP is preferred].