Imaging Uganda/Africa

Indications for Biliary Ultrasound

1. Common Clinical Scenarios

• Right upper quadrant (RUQ) abdominal pain
• Suspected cholelithiasis or choledocholithiasis
• Jaundice (obstructive vs. hepatocellular)
• Abnormal liver function tests (especially elevated ALP and GGT)
• Fever of unknown origin (screening for cholangitis)

2. Specific Clinical Indications

• Acute cholecystitis: RUQ pain + fever + leukocytosis
• Biliary obstruction: Jaundice + pruritus + pale stools
• Post-liver transplant: Monitor for biliary strictures
• Chronic liver disease: Evaluate for secondary biliary changes

Pathological Findings

1. Cholelithiasis (Gallstones)

• Findings: Mobile hyperechoic focus with posterior shadowing
• WES triad: Wall-echo-shadow in contracted gallbladder
• Complications: Cholecystitis, empyema, porcelain gallbladder

2. Choledocholithiasis (CBD Stones)

• Findings: Echogenic intraluminal focus with shadowing
• Dilation: CBD >6 mm with proximal ductal dilation
• Twinkling artifact: May be seen on color Doppler

3. Biliary Obstruction

• Intrahepatic: "Too many tubes" sign (multiple dilated ducts)
• Extrahepatic: "Double barrel" sign (dilated CBD + portal vein)
• Causes: Stones (75%), tumors (20%), strictures (5%)

4. Cholangitis

• Findings: Ductal dilation + wall thickening + intraluminal debris
• Clinical: Charcot's triad (fever, jaundice, RUQ pain)

5. Choledochal Cysts

• Type I: Fusiform dilation of the CBD, are the most common (80%)
• Type II: Are true diverticula of the bile ducts and are very rare
• Typr III: The “choledochoceles,” are confined to the intraduodenal portion of the CBD
• Type IV:
  • Type IVa: Cysts are multiple intrahepatic and extrahepatic biliary dilations
  • Type IVb: Cysts are confined to the extrahepatic biliary tree.
• Type V: Caroli disease has been classiied as a type V cyst. However, it has a diferent embryonic origin and is not a true choledochal cyst.

6. Caroli Disease. A rare congenital disorder characterized by segmental, non-obstructive dilation of intrahepatic bile ducts. Caroli disease leads to saccular dilation or, less often, fusiform dilation of the intrahepatic biliary tree, resulting in biliary stasis, stone formation, and bouts of cholangitis and eventually sepsis. Unlike recurrent pyogenic cholangitis, the ductal contents do not form a cast of the dilated system and thus are more easily identiied as ductal contents.

7. Mirizzi Syndrome. A rare complication of chronic gallstone disease where extrinsic compression of the common hepatic duct (CHD) occurs due to; an impacted gallstone in the cystic duct/gallbladder neck or Secondary inflammation/fibrosis causing biliary obstruction

• Dilated CHD & intrahepatic ducts above the level of obstruction (normal CBD below)
• Impacted stone - Hyperechoic focus with shadowing in gallbladder neck/cystic duct
• Wall thickening - Gallbladder/cystic duct wall >3mm with edema
• "Parallel channel" sign - Dilated CHD adjacent to portal vein
• Gallbladder contraction - Small, shrunken gallbladder
• Pericholecystic inflammation - Hyperechoic fat, fluid collections
• Liver parenchyma changes - Possible edema near porta hepatis

8. Hemobilia. This is due to iatrogenic biliary trauma mostly caused by percutaneous biliary procedures or liver biopsies, cholangitis or cholecystitis, vascular malformations or aneurysms, abdominal trauma, and malignancies. The appearance of blood within the biliary tree is similar to blood clots encountered elsewhere; Most oten, the clot is echogenic or of mixed echogenicity, and retractile, conforming to the shape of the duct. Occasionally, hemobilia may appear tubular with a central hypoechoic area. Acute hemorrhage will appear as fluid with low-level internal echoes. Blood clots may be mobile. Extension into the gallbladder is common.

9. Pneumobilia. Refers to air within the biliary tree, most commonly caused by; Post-surgical states (e.g., sphincterotomy, biliary-enteric anastomosis), Biliary-enteric fistulas (e.g., gallstone ileus), Infection (emphysematous cholecystitis/cholangitis) or Iatrogenic (ERCP, stent placement). Air in the bile ducts has a characteristic appearance. Bright, echogenic linear structures following the portal triads are seen, more oten in a nondependent position. Posterior “dirty” shadowing, reverberation, and ring-down artifacts are seen with large quantities of air. Movement of the air bubbles, best seen just ater changing the patient’s position, is diagnostic.

10. Biliary Tree Infection

• Acute (Bacterial, Ascending) Cholangitis
• Liver Flukes
• Recurrent Pyogenic Cholangitis
• Ascariasis
• HIV Cholangiopathy

11. Immune-Related Diseases of the Biliary Tree

• Primary Biliary Cirrhosis and Autoimmune Cholangitis
• Primary Sclerosing Cholangitis
• IgG4-Related Cholangitis

12. Cholangiocarcinoma

• Intrahepatic Cholangiocarcinoma
• Hilar Cholangiocarcinoma

13. Metastases to Biliary Tree. Metastases to the biliary tree mimic the varied appearance of cholangiocarcinoma, affecting both the intrahepatic and extrahepatic ducts. The history of past or concurrent malignancy along with multiple lesions should suggest metastases. In our experience the breast, colon, and skin (melanoma) constitute the primary sites of malignancy.

Cholelithiasis

• Mobile hyperechoic focus with posterior shadowing.

WES triad

• Wall echo shadow in a contracted gallbladder

Choledocholithiasis

• Small stones (arrow) are seen in the right liver lobe causing acoustic shadowing. Note the dilated duct proximal to the larger stone.

Choledocholithiasis

• Common bile duct (CBD) stones. Small stone (arrow) may not show shadowing

Biliary obstruction

• Intrahepatic (dilated bile ducts)

Biliary obstruction

• Extrahepatic - Double barrel" sign (dilated CBD + portal vein)

Choledochal cyst - Type I

• Fusiform dilation of the common bile duct (CBD) is seen, but no obstructive lesion is noted.

Choledochal cyst - Type II

• A large diverticulum (arrow) arising from the common hepatic duct at the portal hepatis and containing mobile debris.

Choledochal cyst - type III

• Fusiform dilation of the distal CBD (arrow) is demonstrated protruding into the duodenum.

Choledochal cyst - type IV

• Sagittal view of the liver shows a markedly dilated bile duct (BD) and left hepatic duct (LD).

Cholangitis

• Bile duct wall thickening (arrow) in a dilated duct.

Caroli disease

• Oblique image through the right lobe of the liver demonstrates dilated ducts with sacculations typical of Caroli disease..