"blood vessel - embolus or thrombus (on US, or CT/MR or digital angiography)"
"bile duct, ureter - calculi or tumour (on US, MRCP, CT or per-operative cholangiogram)"
"hollow organ - calculi, polyp or tumour, e.g. gallbladder or colon (on US, cholangiography, CT colonography, etc)"
"bile duct, ureter - calculi or tumour (on US, MRCP, CT or per-operative cholangiogram)"
"hollow organ - calculi, polyp or tumour, e.g. gallbladder or colon (on US, cholangiography, CT colonography, etc)"