Abdominal Sonography Part 1 The Biliary Tract Part II Holdorf Abdominal Sonography Part 1 The Biliary Tract Part II

OUTLINE PART 2 Pit Laboratory values Gallbladder carcinoma Adenomyomatosis Biliary obstruction Common duct measurement Dilated Intrahepatic ducts Fatty meal Level of obstruction Choledocholithiasis Mirizzi syndrome Bile duct carcinoma Cholagnitis Biliary atresia Pneumobilia Choledochal cyst Caroli’s disease Pancreatic adenocarcinoma

Laboratory Values Bilirubin Bilirubin is the end product of hemoglobin breakdown. Total bilirubin = conjugated bilirubin + unconjugated bilirubin. Conjugation is the process of removing protein (albumin) from unconjugated bilirubin making it soluble. Conjugation is important for bilirubin disposal. This reaction not only renders the pigment excretable by the liver, but also detoxifies this waste product.

Laboratory Values Increased INDIRECT or UNCONJUGATED bilirubin results from: Increased bilirubin production (hemolysis) or Decreased liver conjugation. Increased DIRECT or CONJUGATED bilirubin (soluble) results from: Decreased biliary excretion (bile duct obstruction).

Laboratory Values Alkaline Phosphatase (ALP) ALP is an enzyme found in bone, liver and placenta. ALP increases in diseases that impair bile formation, specifically BILE DUCT OBSTRUCTION. ALP also increases with bone growth (growing children) and pregnancy. ALP is also a sensitive indicator of liver and bone cancer. ALP increases with: Biliary obstruction Liver disease (Hepatitis, Hepatocellular Ca) Bone growth and diseases Hyperparathyroidism Pregnancy

Gallbladder Carcinoma Presents with an: Intraluminal mass Asymmetric wall thickening or A mass that fills the gallbladder lumen. Associated findings include: Liver metastases Lymphadenopathy Bile duct dilatation (Intra-hepatic) Cholelithiasis

Gallbladder Carcinoma Rare: 2-4 % of all gastrointestinal malignancies Usually unresectable 5 year survival rate of 1%

Gallbladder Carcinoma

Metastatic GB Ca

Adenomyomatosis Hyperplastic changes involving the gallbladder wall causing overgrowth of the mucosa, thickening of the wall, and formation of diverticula. Diverticula within the gallbladder wall (Rokitansky-Aschoff sinuses or RAS) accumulate stones or sludge within them.

Adenomyomatosis Sonograpically seen as hyperechoic foci within a thickened gallbladder wall. Associated with a comet-tail (reverberation) artifact. Differentiating between adenomyomatosis and cholesterolosis may be difficult.

Adenomyomatosis with comet tail artifacts

Adenomyomatosis

Biliary Obstriction In the majority of patients, biliary obstruction is due to pathology of the distal CBD: Gallstones or Carcinoma of the Head of the Pancreas. These are the two most common lesions. Biliary obstruction is considered clinically when the patient presents with jaundice. There may or may not be associated RUQ pain and or a palpable RUQ mass.

Biliary Obstruction Serum alkaline phosphatase and conjugated bilirubin levels are typically elevated. Obstruction of the distal CBD results in progressive dilatation of the extrahepatic and intrahepatic biliary tree (distal to proximal). Causes of biliary obstruction: Choledocholithiasis (Biliary duct stone) Pancreatic carcinoma Cholangiocarcinoma (Carcinoma of the biliary ducts) Cholangitis (Inflammation of the bile ducts Mirizzi Syndrome Choledochal cyst (cystic dilatation of the bile ducts) Gallbladder carcinoma

Biliary Obstruction Distal CBD

Biliary Obstruction- Enlarged CBD and Pancreatic Duct

Common Duct Measurement The common hepatic duct is routinely measured (lumen only) at the point where the right hepatic artery courses between the portal vein and the biliary duct. The size of the extrahepatic bile duct is the most sensitive means of distinguishing medical vs. surgical jaundice. (Medical-due to acute or chronic hepatitis or cirrhosis: Surgical-due to stones, tumors or strictures).

Common Duct Measurement The diameter of the common duct increases with age with 10 mm being the upper normal value in elderly patients. Measurement criteria: 1. One millimeter per decade rule-the common duct diameter increased with age. One millimeter per decade is a acceptable rate of size increase. Thus, at age 60, duct size may normally be 6 mm and at age 80, duct size may normally be 8 mm.

Common Duct Measurement 2. Typically the normal common duct diameters are: Normal < 5 mm Equivocal 6 to 7 mm Dilated > 8 mm Post cholecystectomy, the common duct acts as a reservoir for bile storage and may increase up to 10 mm or 1 cm

Common duct dilated S/P cholecystectomy

Common duct – Shotgun or parallel channel sign

Dilated intrahepatic ducts Criteria to differentiate intrahepatic bile ducts from portal veins: Parallel channel sign or Shotgun sign: refer to the dilated hepatic duct adjacent to the portal vein. Irregular and tortuous bile ducts: biliary ducts are more tortuous than the accompanying portal vein. Stellate confluence: bile ducts branch in a star-shaped configuration. Acoustic enhancement- bile structures attenuate sound less than blood producing posterior acoustic enhancement.

Irregular dilated intrahepatic bile ducts

Fatty Meal Biliary dynamics, gallbladder contractility, or obstruction, can be assessed by administering a fatty meal. Cholecystokinin- a hormone that is released into the blood by the ingestion of fatty foods, causes gallbladder contraction. Equivocal bile duct dilation or abnormal lab values (conjugated bilirubin, alkaline phosphatase) would be reasons to administer a fatty meal. Negative result-unchanged or decreased size. Positive result- duct increase in size

Level of Obstruction The part of the biliary tree that dilates as a result of obstruction depends on the level of obstruction.

Distal Common Bile Duct Obstruction- entire system distends including the gallbladder

Common Hepatic Obstruction. Only proximal ducts will distend Common Hepatic Obstruction. Only proximal ducts will distend. The gallbladder will be contracted.

Obstruction at the junction of the right and let hepatic ducts – Intrahepatic ducts dilate- GB contracted.

Biliary radicals

Choledocholithiasis Formation or presence of calculi in the bile ducts. Most common cause of extrahepatic obstructive jaundice. Symptoms include: Biliary colic (RUQ pain) Jaundice Laboratory values that increase: (all three will increase) Conjugated serum bilirubin Alkaline phosphatase GGT

Definitions Conjugated serum bilirubin Refer back to the laboratory section. GGT (Gamma-glutamyltransferease) GGT is predominantly used as a diagnostic marker for liver diseased. Elevated levels suggests diseases of the liver, biliary system, and pancrease

Choledocholithiasis cont. Complications of choledocholithiasis include: Biliary cirrhosis Cholangitis Pancreatitis Diagnostic Tests include: ERCP (endoscopic retrograde cholangiopancreatography) PTC Percutaneous transhepatic cholangiography CT Ultrasound

Homework: Just what is an ERCP and PTC?

Mirizzi Syndrome Extrahepatic biliary obstruction due to an impacted stone in the cystic duct causing extrinsic mechanical compression of the common duct. Associated findings include: Intrahepatic duct dilation Cystic duct stone Curved segmental stenosis of CHD Cholescystocholedocal fistula

ERCP showing Mirizzi Syndrome

Homework Just what is a Cholescystocholedocal fistula?

Bile Duct Carcinoma Cholangiocarcinoma Bile duct adenocarcinomas usually originate within extrahepatic bile ducts (CHD or CBD). A klatskin Tumor is a cholangiocarcinoma located at the hepatic hilum (junction of right and left hepatic duct) resulting in intrahepatic but not extrahepatic biliary dilation. Predisposing conditions include: Ulcerative colitis Sclerosing cholangitis Carol’s disease Choledochal cyst Parasitic infection Chemical toxins.

Homework: Definitions Ulcerative colitis Sclerosing cholangitis Carol’s disease (soon to come) Choledochal cyst

Bile Duct carcinoma cont. Diagnostic test include: Ultrasound CT Choleangiography- Choleangiography is the imaging of the bile ducts (also known as the biliary tree) by x-rays. There are at least two kinds of cholangiography: percutaneous transhepatic cholangiography (PTC): Examination of liver and bile ducts by x-rays. This is accomplished by the insertion of a thin needle into the liver carrying a contrast medium to help to see blockage in liver and bile ducts. Endoscopic retrograde cholangiopancreatography (ERCP). Although this is a form of imaging, it is both diagnostic and therapeutic, and is often classified with surgeries rather than with imaging.

Cholangitis Infection and inflammation of the biliary ducts resulting in wall thickening that compromises the lumen of the bile duct. Associated with Choledocholithiasis Biliary tract interventions Ulcerative colitis Symptoms Fever Jaundice RUQ pain

Cholangitis cont. Results in increased: Serum conjugated bilirubin Serum alkaline phosphatase Serum amylase and lipase Leukocytosis

Cholangitis

Biliary Atresia Jaundice persisting beyond 4 weeks is most commonly due to biliary atresia or neonatal hepatitis. Absence of the extrahepatic biliary tree. Associated with polysplenia syndrome with abdominal heterotaxia. Sonographically seen as two-vessel portal triad (portal vein and proper hepatic artery seen only)

Biliary atresia is suspected in infants with jaundice. Surgical drainage with the Kasai Portoenterostomy is the most successful in the treatment of biliary atresia if perfumed before 90 days of life.

Definitions Polysplenia syndrome A congenital disease manifested by multiple small accessory spleens. Heterotaxia A rare congenital defect in which the major visceral organs are distributed abnormally within the chest and abdomen. Kasai Portoenterostomy A surgical treatment performed on infants with biliary atresia to allow for bile drainage. In these infants, the bile is not able to drain normally from the small bile ducts within the liver into the larger bile ducts that connect to the gall bladder and small intestine.

Pneumobilia Pneumobilia is air in the biliary system. It is commonly associated with an ERCP (endoscopic retrograde cholangiopancreatogram). Ultrasound findings include variable length echogenic foci in the intrahepatic bile ducts. Comet-tail or reverberation artifacts are typically associated with air in the biliary tree. Arterial calcification may mimic pneumobilia. Plain film radiography can differentiate air from calcifications.

Pneumobilia

Choledochal cyst Congenital anomalies of the bile ducts consisting of cystic dilatation of the intra and extrahepatic bile ducts. Sonographic findings include: Two cystic structures in the RUQ (gallbladder and dilated extrahepatic ducts) Intrahepatic bile duct dilatation

Choledochal cyst cont. Choledochal cysts are prevalent in Asia. More than 33% of reported cases are from Japan. Symptoms usually occur before age 10. Pancreatitis Cholangitis Hepatic abscesses Cirrhosis Portal hypertension cholangiocarcinoma

Choledochal cyst

Caroli’s Disease Congenital abnormality of the biliary tract characterized by multifocal segmental dilatation of the intrahepatic bile ducts. This is a specific type of choledochal cyst. Common in childhood and second to third decades of life. Associated with Congenital hepatic fibrosis Portal hypertension Medullary sponge kidney Infantile polycystic kidney disease Renal tubular ectasia Choledochal cyst

Caroli’s disease cont. Ultrasound findings Multiple cystic structures that converge toward the porta hepatis communicating with the bile ducts. Sludge and calculi may accumulate in these ectatic (dilated) ducts resulting in posterior acoustic shadowing. Complications include: Recurrent cholangitis Biliary calculi and obstruction Hepatic abscess Cholangiocarcinoma

Caroli’s disease

Caroli’s Disease

Pancreatic Adenocarcinoma Most common cause of malignant neoplasm obstructing the biliary tree. Pancreatic adenocarcinoma at the head of the pancreas typically causes “Courvoisier gallbladder”. This is an enlarged, non-diseased gallbladder due to a mechanical obstruction of the common bile duct.

Courvoisier gallbladder

Homework for Part 2 What are Rokitansky-Aschoff Sinuses? What pathology is associated with Rokitansky-Aschoff Sinuses? What is the sonographic presentation of gallbladder Carcinoma? What three other findings should be investigated to confirm the diagnosis of gallbladder carcinoma? What are the two most common causes of biliary tract obstruction? What lab values are most likely to be elevated due to biliary tract obstruction? What are the two signs that indicate intrahepatic bile duct dilatation? Name three extra hepatic biliary ducts. What pathology causes intrahepatic dilatation without extra hepatic biliary dilatation? Describe the sonographic appearance of pneumobilia (air in the biliary tree.) What is the most common reason for pneumobilia? Choledochal cyst usually occurs in Asian women. Symptoms of pain, jaundice, and an abdominal mass may be present. What are the sonographic features associated with a choledochal cyst? What is the sonographic appearance of Caroli’s disease? What other genetically acquired conditions are associated with Caroli’s disease? What is a Courvoisier gallbladder? Describe the sonographic appearance of milk of calcium bile. Bile duct carcinoma (cholangiocarcinoma) is an uncommon cancer. What predisposing conditions are associated with this cancer? What is the name of the cholangiocarcinoma located at the hepatic hilum?