Chapter 10

GB polyp (adenoma)

Benign epithelial tumor Clinically- asymptomatic or dull RUQ pain Sono: Echogenic intraluminal focus Non-mobile Non-shadowing GB wall thickening

GB Metastatic Extension

Direct Extension: Pancreas Stomach Bile duct Indirect Extension Melanoma - most common Lung Kidney Esophagus Sono: Focal GB wall thickening Intraluminal mass Non-shadowing Absence of gallstones

Intrahepatic Biliary Neoplasms

Found more frequently in middle-aged women clinical presentation includes abdominal pain or mass or jaundice or both (if the mass is near the porta hepatis). Sonographic appearance: Cystic mass with multiple septa and papillary excrescences Mass may show variations in this pattern and appear as unilocular, calcified, or multiple. Lesion may be associated with dilation of the intrahepatic ducts. Differential diagnoses include a hemorrhagic cyst or infection, echinococcal cyst, abscess, or cystic metastasis.

Dilated Biliary Ducts- CHD

The common hepatic duct has an internal diameter of <4 mm. A duct diameter of 5 mm is borderline, and 6 mm requires further investigation. A patient may have a normal-size hepatic duct and still have distal obstruction. The common bile duct has an internal diameter slightly greater than that of the hepatic duct. Generally a duct >6 mm in diameter is considered borderline; >10 mm is dilated. Most common cause is the presence of a tumor or thrombus within the ductal system**. Process may be found in the extrahepatic or intrahepatic ductal pathway. Obstruction of biliary ductal system is diagnosed by ultrasound when the sonographer finds the presence of ductal dilation. This finding is called "too many tubes" or "shotgun" sign when intrahepatic ducts are dilated. Fibrosed or infiltrative disease of the liver may prevent intrahepatic dilation because of a lack of compliance of the hepatic parenchyma. Painful jaundice is seen with acute obstruction or infection that may invade the biliary tree.

Hepatic ducts

The common hepatic duct is approximately 4 mm in diameter Variable with age Descends within the edge of the lesser omentum. It is joined by the cystic duct to form the common bile duct.

Mirizzi Syndrome

Uncommon impacted stone in the cystic duct, which creates extrinsic mechanical compression of the common hepatic duct. Patient presents with painful jaundice .Stones may penetrate into the common hepatic duct or the gut, resulting in a cholecystobiliary or cholecystenteric fistula. Cystic duct inserts unusually low into the common hepatic duct; thus the two ducts have parallel alignment, which allows for the development of this syndrome. On ultrasound, an intrahepatic ductal dilation is seen with a normal-size common duct and a large stone in the neck of the gallbladder or cystic duct.

Cholecystitis

inflammation of the GB Several forms Acute or chronic Acalculous Emphysematous -Gangrenous

GB removal

(cholecystectomy)The sphincter of Oddi loses tonus. Pressure within the common bile duct drops to that of intraabdominal pressure. - Bile is no longer retained in the bile ducts; it is free to flow into the duodenum during fasting and digestive phases. -The extrahepatic bile ducts dilate, usually less than 1 cm.

Sludge

, or thickened bile, frequently occurs from bile stasis May be seen in patients with prolonged fasting hyperalimentation therapy obstruction of the gallbladder Sono Non-shadowing low-amplitude echoes Layers in the dependent portion of the GB Echoes move slowly with position change Can fill entire GB Can appear as a sludge ball Can contain small stones

GB variants

-The most common variant of the gallbladder is the Phrygian cap. Junctional fold- fold at neck Hartmann pouch- small posterior pouch at GB neck

Adenomyomatosis

A hyperplastic change in the gallbladder wall Papillomas may occur singly or in groups and may be scattered over a large part of the mucosal surface of the gallbladder .Papillomas are not precursors to cancer .Various patient positions and compression show the lesion to be immobile in the gallbladder

Distinguishing Bile Ducts from Intrahepatic Structures

Alteration in the anatomic pattern: Is adjacent to the main (right) portal vein segment and the bifurcation. This appearance is more pronounced in individuals who display greater degrees of dilation of the intrahepatic bile ducts. Irregular walls of dilated bile ducts: As the intrahepatic biliary system dilates, the course and caliber of ducts become increasingly tortuous and irregular. Stellate confluence of dilated ducts: This appearance is noted at the points where the ducts converge. Dilated ducts look similar to the spokes of a wheel. Acoustic enhancement by dilated bile ducts: Both portal veins and ducts are surrounded by high-amplitude reflections. Peripheral duct dilation: Visualizing hepatic ducts in the liver periphery is normally unusual, whereas dilated bile ducts may be observed.

GB torsions

Although the occurrence is rare, the floating variant does have potential for twisting off of the blood supply, resulting in a condition termed gallbladder torsion or gallbladder volvulus, in which the patient will present with right upper quadrant pain. Very rare Elderly women Associated with a mobile gallbladder with a long suspensory mesentery Symptoms present typical of acute cholecystitis. Sonographic findings -Gallbladder massively inflamed and distended -Cystic artery and cystic duct may become twisted If the gallbladder becomes twisted more than 180 degrees, then a risk of gangrene exists. Surgical intervention is the treatment.

Hemobilia

Blood in the bile ducts Main cause of hemobilia is biliary trauma secondary to percutaneous biliary procedures or liver biopsies Other causes include: Cholangitis, cholecystitis, vascular malformations, abdominal trauma, and malignancies Clinical findings Pain BleedingJaundice Sonographic appearance of blood in the biliary tree Depends on the length of time the blood has been present Acute hemorrhage will appear as fluid with low-level internal echoes. Look for blood clots that may move in the duct with extension into the gallbladder.

Other Causes of Obstruction

Cholangiocarcinoma Klatskin tumor Mirizzi Syndrome Tumors arising from the common bile duct and ampullar carcinoma have the same ultrasonic features as pancreatic tumors. A specific pattern exists when the ampulloma bulges inside a dilated common bile duct. Cancer of the biliary convergence or of the hepatic duct usually infiltrates the ductal wall without bulging outside. Imaging these tumors may be difficult; the diagnosis is indirect and based on biliary dilation above the tumor.

Cholangitis

Cholangitis is an inflammation of the bile ducts.Causes: Congenital or acquired stricture InfectionParasiteBiliary stasisUlcerative colitis AIDS Cholangitis May be identified as Oriental sclerosing cholangitis. Other forms include •AIDS cholangitis•acute obstructive suppurative cholangitis Patients have malaise and fever, followed by sweating and shivering, right upper quadrant pain, and jaundice. In severe cases, patient is lethargic and in shock. Laboratory values show leukocytosis and an elevation of serum alkaline phosphatase and bilirubin. Sono: Biliary dilation Thickening of bile duct walls PneumobiliaGB hydrops

Choledochal Cysts

Congenital cystic dilation of the biliary tree Can be focal or diffuse May be the result of pancreatic juices refluxing into the bile duct •because of an anomalous junction of the pancreatic duct into the distal common bile duct •causing duct wall abnormality, weakness, and outpouching of the ductal walls Rare More common in women than in men (4:1) Increased incidence in infants May be associated with gallstones, pancreatitis, or cirrhosis Symptoms Abdominal mass Pain Fever Jaundice Diagnosis may be confirmed with a nuclear medicine hepatobiliary scan Type I is a fusiform dilation of the common bile duct. Most common, along with type Iva Associated with a long common channel (>20 mm) between the distal bile duct and the pancreatic duct Type II cysts are true diverticuli of the bile ducts. Type III cysts (choledochoceles) are confined to the intraduodenal portion of the common bile duct. Type IVa cysts are intrahepatic and extrahepatic biliary dilations. Type IVb cysts are confined to the extrahepatic biliary tree. Type V cysts have been classified as Caroli's disease.

Ascariasis

Disease is caused by the parasitic roundworm, Ascaris lumbricoides, which uses a fecal-oral route of transmission. The worms may be 20 to 30 cm long and 6 cm in diameter. The worms grow in the small bowel before entering the biliary tree through the ampulla of Vater. Cause acute biliary obstruction Clinically, the patient may be asymptomatic or have biliary colic, pancreatitis, or biliary symptoms. Sono: •Spaghetti-like echogenic structure in the bile ducts •Non-shadowing •Posterior enhancement

congenital abnormalities

Duplication- can be partial or complete Septations Floating gallbladder Agenesis Intrahepatic or ectopic location Hypoplasia•Associated with cystic fibrosis

Courvoisier's GB

Enlarged, hydropic GB Painless jaundice Typically due to a pancreatic head mass compressing the distal bile duct

Hydropic GB

Enlargement of the GB Causes:Obstruction of the cystic duct -Prolonged biliary stasis Surgery Hepatitis DM -Gastrinitits

GB layers

GB 3 wall layers: mucosal layer fibromuscular layer serosal layer The gallbladder has a neck, body, and fundus. The neck is contiguous with the cystic duct which connects the gallbladder to the rest of the biliary tree -Venous drainage- Cystic vein -Empties into portal vein -Blood supply is via the cystic artery Branch of right hepatic artery

Hilar Cholangiocarcinoma

Includes jaundice, pruritus, and elevated cholestatic liver parameters. Begins in the right or left bile duct and then extends into the proximal duct and distally into the common hepatic duct and contralateral bile ducts. Tumor may extend outside of the ducts to involve the adjacent portal vein and arteries. Chronic obstruction leads to atrophy of the involved lobe. Majority of patients die within 1 year of diagnosis.

Gangrenous Cholecystitis

Is a serious, painful complication of acute cholecystitis that may lead to perforation. Perforation- tear in GB wall, GB rupture Gangrene- tissue loss due to decreased blood supply Occurs after a prolonged infection, which causes the gallbladder to undergo necrosis. Ulcerations and perforations may be present, resulting in pericholecystic abscesses or peritonitis. Gallstones or fine gravel occur in 80% to 95% of patients. The common echo feature of gangrene is the presence of diffuse medium to coarse echogenic densities filling the gallbladder lumen in the absence of bile duct obstruction. This echogenic material has the following three characteristics Does not cause shadowing Is not gravity-dependent Does not show a layering effect Gallbladder wall may be thickened and edematousWall striations or intraluminal membranes

Distal Cholangiocarcinoma

Is difficult to distinguish from hilar cholangiocarcinoma; progressive jaundice is seen in the majority of patients. Tumor mass may be sclerosing or polypoid. Tumor spread in the superior ductal system and extrahepatic area should be carefully evaluated. May extend into the adjacent lymph nodes.Sonographic findings Sclerosing tumor is nodular with focal irregular ductal constriction and wall thickening. Has a hypoechoic and hypovascular appearance with poorly defined margins

Acalculous Cholecystitis

Is the acute inflammation of the gallbladder in the absence of cholelithiasis 5-10% of acute cholecystitis cases Is most likely caused by decreased blood flow through the cystic artery Extrinsic compression of the cystic duct by a mass or lymphadenopathy may also cause this condition. Conditions that produce depressed motility (e.g., trauma, burns, postoperative patients, HIV, etc.) may precede the development of acalculous cholecystitis Clinically, the patient has a positive Murphy's sign.

Klatskin Tumor

Klatskin tumor is a specific type of cholangiocarcinoma that can occur at the bifurcation of the common hepatic duct, with involvement of both the central left and right ducts. The most suggestive sonographic feature that indicates cholangiocarcinoma is isolated intrahepatic duct dilation. Although the obstructing mass may not be imaged, a nonunion of the right and left ducts is characteristic for a Klatskin tumor. Sono: Small echogenic mass near hepatic hilum Dilation of the intrahepatic bile ducts Normal extrahepatic ducts

Acute Cholecystitis

Most common cause of is gallstones Other causes: Infection or idiopathic Acute cholecystitis is caused by stones being impacted in the cystic duct or in the neck of the gallbladder (Hartmann's pouch). Acute right upper quadrant pain -Positive Murphy's sign Inspiratory arrest upon palpation of gallbladder area Fever Nausea/vomiting Leukocytosis -Increased serum bilirubin and alkaline phosphatase levels Risk Factors Female prevalence 40-50 years Cholelithiasis ComplicationsEmpyemaemphysematous or gangrenous cholecystitis Perforation Ascending cholangitis Gallbladder wall >3 mm Distended gallbladder lumen >4 cm Gallstones• Cholelithiasis seen in 90% of cases Impacted stone in Hartmann's pouch or cystic duct Positive Murphy's sign Increased color Doppler flow Pericholecystic fluid collection

Cholelithiasis

Most common disease of the gallbladder Single, large gallstone or multiple tiny stones Tiny stones are the most dangerous because they can enter the bile ducts and obstruct the outflow of bile .After a fatty meal, the gallbladder contracts to release bile; if the outflow tract is blocked by gallstones, then pain results. Patients may be asymptomatic until a stone lodges in the cystic or common duct. RUQ pain with radiation to the shoulder after a high-fat meal is a typical presentation for cholelithiasis. Epigastric pain, nausea, and vomiting develop when the symptoms become acute. Patients often fall under the category of the "five Fs": fat, female, forty, fertile, and fair Other risk factors include pregnancy, diabetes, oral contraceptive use, hemolytic diseases, diet-induced weight loss, and total parenteral nutrition.

Chronic Cholecystitis

Most common form of gallbladder inflammation Result of numerous attacks of acute cholecystitis with subsequent fibrosis of the gallbladder wall Clinically, patients may have some transient RUQ pain, but not the tenderness as experienced with acute cholecystitis .Sono- does not appear different from acute cholecystitis

Metastases to the Biliary Tree

Most common tumor sites that can spread to the biliary system are from the breast, colon, or melanoma.** Metastases can affect the intrahepatic and extrahepatic ductal systems. On sonography, the appearance of metastases is similar to that of cholangiocarcinoma.

Reasons for no visible GB

Non-fasting pt Surgically absent Obliteration of GB lumen by air or stone Patient body habitus Ectopic location Agenesis

CBD

Normal common bile duct has a diameter of up to 7 mm. The first part of the duct lies in the right free edge of the lesser omentum. The second part of the duct is situated posterior to the first part of the duodenum.The third part lies in a groove on the posterior surface of the head of the pancreas. It ends by piercing the medial wall of the second part of the duodenum approximately halfway down the duodenal length. The common bile duct is joined by the main pancreatic duct; together they open through a small ampulla (the ampulla of Vater) into the duodenal wall.

Suprapancreatic Obstruction

Originates between the pancreas and the porta hepatis The head of the pancreas, the intrapancreatic duct, and pancreatic duct are normal with ultrasound. The most common cause for this obstruction is malignancy or adenopathy at this level.

Pneumobilia

Pneumobilia is air within the biliary tree secondary to biliary intervention, biliary-enteric anastomoses, or common bile duct stents. In the patient with an acute abdomen, pneumobilia may be caused by the following: Emphysematous cholecystitis Inflammation from an impacted stone in the common bile duct Prolonged acute cholecystitis, which may lead to erosion of the bowel Sonographic findings The air in the bile ducts appears as bright, echogenic linear structures that follow the portal triads. The posterior dirty shadow and reverberation artifact are seen. Movement of tiny air bubbles with a change in the patient's position should be noted.

GB carcinoma

Primary carcinoma of the gallbladder is rare and is nearly always a rapidly progressive disease with a mortality rate approaching 100%. Associated with cholelithiasis in approximately 80% to 90% of patients Twice as common as cancer of the bile ducts, and occurs most frequently in women >60 years of age Arises in the body of the gallbladder or rarely in the cystic duct Tumor infiltrates the gallbladder locally or diffusely and causes a thickening and rigidity of the wall. Adjacent liver is often invaded by direct continuity, extending through tissue spaces, the ducts of Luschka, the lymph channels, or some combination of these.

Choledocholithiasis

Primary choledocholithiasis is the formation of calcium stones in the bile duct. These stones may result from disease, causing strictures or dilation of the bile ducts, leading to stasis .•Sclerosing cholangitis, Caroli's disease, parasitic infections, chronic hemolytic diseases, prior biliary surgery Secondary choledocholithiasis denotes the majority of stones in the common bile duct have migrated from the gallbladder. Common duct stones are usually associated with calculous cholecystitis.

Emphysematous cholecystitis

Rare complication of acute cholecystitis The presence of gas-forming bacteria in the gallbladder wall and lumen with extension into the biliary ducts Rapidly progressive and fatal in 15% of patients •Surgical emergency Gangrene with associated perforation is a complication Risk Factors Affects men more often 50% are diabetic Sonographic appearance depends on the amount of gas within the wall of the gallbladder Gallstones may not be present in 30% to 50% of patients If the gas is intraluminal Prominent bright echo is demonstrated along the anterior wall with a ring down or comet-tail artifact directly posterior to the echogenic structure. If a large amount of gas is present Appears as a "packed bag" or WES sign with a curvilinear echogenic area with complete posterior fuzzy shadowing

Carolis disease

Rare congenital abnormality most likely inherited in an autosomal recessive fashion Type 5 choledochal cyst Communicating cavernous ectasia of the intrahepatic ducts congenital segmental saccular cystic dilation of major intrahepatic bile ducts (multiple cystic dilations) Found in the young adult or pediatric population Symptoms: recurrent cramplike upper abdominal pain Intermittent jaundice Abdomen pain Fever May be associated with renal disease or congenital hepatic fibrosis Cystic disease of the kidney (medullary sponge kidney) is strongly associated with Caroli's disease. Two types of Caroli's disease Simple classic form More common form associated with periportal hepatic fibrosis Multiple cystic structures in the area of the ductal system converge toward the porta hepatis. Masses seen as localized or diffusely scattered cysts communicate with the bile ducts. Differential diagnosis includes polycystic liver disease. Ducts may show a beaded appearance as they extend into the periphery of the liver. Ectasia of the extrahepatic and common bile ducts may be present. Sludge or calculi may reside in the dilated ducts. Segmental, saccular, or beaded appearance of the intrahepatic bile ducts Multiple cystic structures in the liver that communicate with the biliary tree

Cholangiocarcinoma

Rare malignancy that originates within the larger bile ducts (usually the common duct or common hepatic duct) Intrahepatic cholangiocarcinoma Is the second most common primary malignancy of the liver*** Incidence of this tumor has risen, secondary to increasing number of patients with liver cirrhosis and hepatitis C infection. These tumors are often unresectable with a poor prognosis. Sonographic findings Large hepatic mass Hypoechoic to hyperechoic Heterogeneous texture or hypovascular solid mass Biliary ductal dilation associated with these obstructive masses in one third of cases

Porcelain Gallbladder

Rare occurrence that is defined as calcium incrustation of the gallbladder wall. Associated with gallstones in the majority of patients a form of chronic cholecystitis Occurs more often in older female patients Diagnosis made as an incidental finding or mass found on physical examination Significance: 25% of these patients will develop cancer on the gallbladder wall. Bright echogenic echo is seen in the region of the gallbladder with posterior shadowing .The differential will include a packed bag or WES sign.

Hyperplastic Cholecystitis

Represented by a variety of degenerative and proliferative changes of the gallbladder Hyperconcentration Hyperexcitability Hyperexcretion Two types of hyperplastic cholecystitis: Cholesterolosis Adenomyomatosis A condition in which cholesterol is deposited within the lamina propria of the gallbladder. The disease process is associated with cholesterol stones in 50% to 70% of patients. Often referred to as a "strawberry gallbladder"because the mucosa resembles the surface of a strawberry. Most patients do not show thickening of the gallbladder wall. Small percentage of patients with this condition will show cholesterol polyps. Polyps are small, well-defined soft-tissue projections connected by the stalk to the gallbladder wall. These polyps are usually found in the middle third of the gallbladder and are <10 mm in diameter.

Clinical signs of GB disease

Right upper quadrant (RUQ) abdominal pain develops after the ingestion of greasy foods. -Nausea and vomiting sometimes occur and may indicate the presence of a stone in the common bile duct. -A gallbladder attack may cause pain in the right shoulder. -Jaundice is a clinical sign of gallbladder disease. -Increased LFTs -intolerance to fatty foods Positive Murphy sign -Postprandial pain

GB physiology

The gallbladder is located posterior to the right lobe of the liver within the gallbladder fossa intraperitoneal organ Function- store bile The gallbladder contracts as a result of cholecystokinin, a hormone released by the duodenum. -The normal gallbladder generally measures 2.5 to 4 cm in diameter and 7 to 10 cm in length. -The walls are less than 3 mm thick. Dilation of the gallbladder is known as hydropsOver 5cm in TRV

Porta Hepatic Obstruction

This area of obstruction is usually the result of a neoplasm. In patients with obstruction at the level of the porta hepatis, ultrasound will show intrahepatic ductal dilation and a normal common duct. Hydrops of the gallbladder may be present.

Extrahepatic Biliary Obstruction

Three primary areas for biliary obstruction: Intrapancreatic Suprapancreatic Porta hepatic Three conditions cause the majority of biliary obstruction at the level of the distal duct and cause the extrahepatic duct to be entirely dilated: Pancreatic carcinoma Choledocholithiasis Chronic pancreatitis with stricture formation