Category Gastrointestinal Imaging

Extrahepatic Bile Duct Tumors

Etiology The exact pathogenesis of bile duct carcinoma has not been described, but predisposing factors are similar to those causing intrahepatic bile duct neoplasms. It is believed that long-standing inflammation causes metaplasia and, finally, carcinogenesis. Prevalence and Epidemiology Tumors of…

Intrahepatic Bile Duct Tumors

Etiology The exact pathogenesis of bile duct carcinoma has not been described, but predisposing factors include long-standing inflammation, parasitic infestation, toxin and drug exposures, and genetic abnormalities. It is believed that repeated inflammation leads to chronic bile duct injury with…

Tumors of the Gallbladder

Etiology The precise cause of gallbladder carcinoma is unknown, but cholelithiasis and pancreaticobiliary malformations are major risk factors. Gallstones and reflux of pancreaticobiliary enzymes are thought to result in chronic repetitive inflammation of the gallbladder mucosa that, over time, may…

Dilated Bile Ducts

Etiology Biliary dilatation can occur as a result of biliary obstruction, from an altered functional state (e.g., after cholecystectomy or with sphincter of Oddi dysfunction), or uncommonly as a result of a choledochal cyst. The role of imaging is to…

Diffuse Pancreatic Disease

General Considerations Diffuse involvement of the pancreas can occur with various inflammatory, infective, infiltrative, or neoplastic disorders. Any pathologic process that involves the pancreas focally also can cause diffuse involvement ( Box 51-1 ). More common causes of diffuse pancreatic…

Miscellaneous Pancreatitis

Autoimmune Pancreatitis Etiology Autoimmune pancreatitis (AIP) is a peculiar form of chronic pancreatitis characterized by a fibroinflammatory process involving multiple organs with characteristic histopathologic and serologic features, association with other autoimmune disorders, and a propensity to respond to corticosteroid therapy…

Imaging of Chronic Pancreatitis

Etiology Chronic pancreatitis is defined as an ongoing prolonged in­flammatory disease characterized by progressive irreversible structural changes resulting in permanent loss of endocrine and exocrine function. The Cambridge classification of 1983 acknowledged that chronic pancreatitis is typically associated with abdominal…

Cystic Lesions of the Pancreas

Etiology Cystic lesions of the pancreas encompass a wide spectrum of different pathologic entities, ranging from developmental, to inflammatory, to neoplastic cysts. Neoplastic cystic lesions, which are the most important, owing to their profound impact on patient prognosis and the…

Solid Pancreatic Masses

Etiology The term solid pancreatic masses, in its wide meaning, encompasses neoplastic lesions and non-neoplastic masses, ranging from anatomic variants, such as pancreatic head lobulations, to focal inflammatory processes and neoplasms. This chapter will mainly discuss solid pancreatic neoplasms and…