Pancreatic and ampullary carcinoma. Ultrasound, computed tomography, magnetic resonance imaging and angiography.

Ultrasound remains the most readily available and least expensive of the imaging techniques used in assessment of the upper abdomen. Ultrasound is very useful in the detection of pancreatic tumors as well as in the evaluation of the extent of the disease. If ultrasound fails technically or is inconclusive, CT is recommended. Determination of CA 19-9 may help to decide whether ultrasound should be followed by CT or other examinations (51). Patients with any equivocal or inconclusive abnormality on ultrasound or CT should undergo ERCP. Even when ultrasound and CT of the pancreas appear normal there may be an indication for performing ERCP if the clinical suspicion of pancreatic cancer is still strong (52). Angiography is a reliable method of assessing major vascular tumor involvement, which to most surgeons would be a sign of unresectability. Although for some investigators CT is superior to angiography in assessing vascular involvement, angiography is performed preoperatively in many cases because it delineates the vascular anatomy, which can be abnormal in up to one third of patients. Percutaneous biopsy is an important technique for confirming the radiologic diagnosis of unresectable pancreatic carcinoma, particularly for differentiating pancreas carcinoma from other focal pancreatic lesions such as islet cell tumor, lymphoma, and chronic pancreatitis.