he advantages of ERCP include direct visualization of the ampullary region and direct access to the distal common bile duct for cholangiography or choledochoscopy

MRI with magnetic resonance cholangiopancreatography (MRCP) offers a focused, noninvasive test for the diagnosis of biliary tract and pancreatic diseas

The primary use of biliary scintigraphy is in the diagnosis of acute cholecystitis, which appears as a nonvisualized gallbladder, with prompt filling of the common bile duct and duodenum.

CT is also the initial test of choice in evaluating patients with suspected malignancy of the gallbladder, the extrahepatic biliary system, or nearby organs such as the head of the pancreas.

Small stones in the common bile duct frequently get lodged at the distal end of it, behind the duodenum, and are, therefore, difficult to detect

extrahepatic bile ducts are also well visualized by transabdominal ultrasound, with the exception of the retroduodenal portion

Transabdominal ultrasound is the initial investigation of any patient suspected to have disease of the biliary tree.

An elevated white blood cell (WBC) count may indicate or raise suspicion of acute cholecystitis (infection within the gallbladder). If associated with an elevation of bilirubin, alkaline phosphatase, and transaminases, cholangitis (infection within the biliary tree) should be suspected. Cholestasis (an obstruction to bile flow) is generally characterized by an elevation of conjugated bilirubin and a rise in alkaline phosphatase, but it may have no transaminitis. Such a pattern may suggest choledocholithiasis (stones in the common bile duct) or an obstructing lesion such as a stricture or cholangiocarcinoma. I

CK is released endogenously from the enteroendocrine cells in the duodenum in response to a mea

One of the main stimuli to this coordinated effort of gallbladder emptying is the hormone cholecystokinin (CCK).

Hydrochloric acid, partly digested proteins, and fatty acids entering the duodenum from the stomach after a meal stimulate the release of secretin from the S-cells of the duodenum, and increases bile production and flow.

The cystic artery arises from the right hepatic artery in about 90% of cases, but it may arise from the left hepatic, common hepatic, gastroduodenal, or superior mesenteric arteries

Anomalies of the hepatic artery and the cystic artery are quite common, occurring in as many as 50% of cases

Additional small bile ducts (of Luschka) may drain directly from the liver fossa into the body of the gallbladder. If present, but not recognized at the time of a cholecystectomy, a bile leak and subsequent accumulation of bile (biloma) may occur in the abdom

A partially or completely intrahepatic gallbladder is associated with an increased incidence of cholelithiasis,

bout 70% of people, these ducts unite outside the duodenal wall and traverse the duodenal wall as a single duct. In about 20%, they join within the duodenal wall and have a short or no common duct, but open through the same opening into the duodenum. In about 10%, they exit via separate openings into the duodenum, termed pancreas divisum.

spiral valves of Heister.

equently, a visible lymph node (Lund’s or Mascagni’s node, often referred to as Calot’s node) overlies the insertion of the cystic artery into the gallbladder wall

hen the cystic artery reaches the neck of the gallbladder, it divides into anterior and posterior divisions.

hepatic duct is longer than the right and has a greater propensity for dilatation as a consequence of distal obstruction.