Pancreatic imaging. Computed tomography and magnetic resonance imaging.
In the assessment of patients with acute pancreatitis, CT is the modality of choice and should be used in any patient in whom the diagnosis is in doubt, treatment has not been successful, or complications are suspected. Early diagnosis of patients at risk is facilitated by CT, and newly introduced staging criteria have proved to be accurate and helpful in managing these patients. For chronic pancreatitis, CT, ultrasound, and ERCP can be used. ERCP, however, remains the gold standard, owing to its ability to depict the pancreatic duct accurately. Often the morphologic data need to be correlated with exocrine or endocrine dysfunction of the pancreas to obtain an accurate means of staging the severity of chronic pancreatitis. Great advances in imaging of pancreatic neoplasms have been made, and differentiation between various types of tumors involving this gland often can be ascertained. Nevertheless, at this time, the early diagnosis of small, malignant lesions of the pancreas is impossible in many cases. CT and to a lesser degree ultrasound are currently the methods of choice for detecting and staging the pancreatic neoplasms pictorially, whereas ERCP has established itself as the best method for visualizing the pancreatic duct and its changes related to pancreatic neoplasia. MR imaging of the pancreas has come a long way, and further improvements are expected with the use of oral and intravenous contrast agents. At present, MR imaging appears to be mainly a problem-solving modality, but it can show improved results for small lesions (particularly islet cell tumors), which do not alter the contour of the pancreas. MR imaging appears to be capable of discerning between the serous and mucinous components of cystic neoplasms and may have a role in the assessment of patients suspected of pancreas transplant rejection.