Cystic Dilatation of the Extrahepatic Bile Duct

Mechanical biliary obstruction is the most common cause of extrahepatic bile duct dilatation. Upon initial imaging, an obstructive lesion should be sought. Once an obstructive lesion is excluded, congenital etiologies of bile duct dilatation should be considered. Choledochal cysts, unlike obstructive dilatation, generally have more focal ex-trahepatic bile duct dilatation or are typically more expansive than is usually encountered in mechanical dilatation (Fig. 2). It may be more difficult to differentiate a choledochal cyst that has mild or fusiform dilatation of the extrahepatic duct from a duct that is dilated secondary to an obstructing lesion. In these cases, magnetic resonance cholangiopancreatography (MRCP) and/or endo-scopic retrograde cholangiopancreatography (ERCP) are useful to exclude an obstructing lesion and to evaluate the pancreaticobiliary junction [9]. An anomalous pancreati-cobiliary junction is commonly observed in patients with choledochal cyst. Occasionally, pancreatic pseudocysts, echinococcal cysts, and cystic biliary neoplasms such as biliary cystadenoma or biliary cystadenocarcinoma may occur in or around the porta hepatis, simulating a biliary dilatation and choledochal cyst. The appearance of rimlike calcification and enhancing septations or mural nodules should help to establish the diagnosis of a biliary cystadenoma or cystadenocarcinoma. Likewise, echinococcal cysts generally have evidence of inner membranes, daughter cysts, or rim-like peripheral calcification. MR of echinococcal cysts may show a low-

Dilatation Pancreatic Duct

Fig. 2. Choledochal cyst in a three-year-old boy evaluated for a palpable right upper quadrant mass. a Transverse sonogram at the level of the pancreatic head shows dilatation of the common bile duct. b MRCP shows a Todani Type IV choledochal cyst with marked extrahepatic bile duct dilatation extending into the right and left hepatic ducts, cystic duct, and gallbladder

Fig. 2. Choledochal cyst in a three-year-old boy evaluated for a palpable right upper quadrant mass. a Transverse sonogram at the level of the pancreatic head shows dilatation of the common bile duct. b MRCP shows a Todani Type IV choledochal cyst with marked extrahepatic bile duct dilatation extending into the right and left hepatic ducts, cystic duct, and gallbladder signal intensity fibrous capsule and membranes on T2-weighted images.

10 Ways To Fight Off Cancer

10 Ways To Fight Off Cancer

Learning About 10 Ways Fight Off Cancer Can Have Amazing Benefits For Your Life The Best Tips On How To Keep This Killer At Bay Discovering that you or a loved one has cancer can be utterly terrifying. All the same, once you comprehend the causes of cancer and learn how to reverse those causes, you or your loved one may have more than a fighting chance of beating out cancer.

Get My Free Ebook


Post a comment