Teaching points:

• choledocholithiasis can be diagnosed with CT - liver windows help to see the stones
• mild cholangitis may serve as a hint (as in this case), evidenced by mild diffuse enhancement of the walls
• you can still have choledocholithiasis with normal caliber bile ducts
• check the liver function tests when reading the CT to determine your degree of suspicion; these stones were detected because of careful evaluation after finding out the bilirubin was elevated (they are admittedly quite subtle)
• this patient does NOT need and MRCP - they can go right to ERCP