Roentgen Ray 1997

uhrad.com - Abdominal Imaging Case of the Day

Case #3

by: Thomas Herbener, M.D.
Sharyl Pickering, M.D.

Diagnosis: Recurrent Pyogenic Cholangitis.

Fig. 3A: Enhanced CT scan shows dilated intrahepatic bile ducts in the right lobe (arrow).

Fig. 3B: Enhanced CT scan shows markedly dilated bile ducts in the left lobe (arrows).
Note how the ducts are nearly filled with debris and stones which is more dense than bile.

Fig. 3C: Enhanced CT scan showing markedly dilated common duct (arrow)
with a small focus of air in adjacent surgical clips (short arrow).

Fig. 3D: CT scan from four years earlier showing dilated,
debris-filled intrahepatic bile ducts (between arrows).

Discussion: Recurrent pyogenic cholangitis (RPC) or Oriental cholangiohepatitis is a recurrent and chronic and biliary tract infectious process typically seen in the Asian population, particularly Chinese. The disease involves recurrent episodes of infectious cholangitis with fever, abdominal pain, and jaundice. The patient presented here was from China with classic history with recurrent episodes of cholangitis. The causative infectious agents are typically bacterial such as E. coli and other coliforms. However biliary tract parasites such as Ascaris lumbricoides and Clonorchis sinensis are common coexistent pathogens, and it is not clear which infectious agents are the primary cause or representative of secondary superinfection.[1-8].

The recurrent infections lead to bile duct dilatation, strictures, obstruction, and calculi. The bile duct dilatation may be pronounced and involves both the intrahepatic and extrahepatic ducts. There is a predilection for ductal involvement in the left lobe of the liver but diffuse intrahepatic disease can be seen. The extrahepatic bile duct can be quite dilated up to as much as 3-4cm in diameter. The dilatation of the extrahepatic duct may be secondary to loss of elasticity of the duct wall due to chronic infection or it may be due to ampullary narrowing.[2,3].

Debris and calculi in RPC can fill the dilated ducts. The calculi are typically bile pigment stones with varying amounts of calcium. The stones have a mud or paste-like consistency. The stones presumably form due to bacterial enzymes causing deconjugation of bilirubin which then precipitates as calcium bilirubinate. In addition it has been postulated that a low protein diet as is seen in some Asian populations may play a role in formation of intraductal stones.[4]

Computed tomography is one of the best imaging modalities for RPC and the findings on CT reflect the pathology.[5] Focal or diffuse intrahepatic ductal dilatation is seen usually associated with pronounced extrahepatic duct dilatation. The pattern of intrahepatic and extrahepatic ductal dilatation along with the pronounced degree of dilatation can aid in differentiating RPC from other entities such as ascending cholangitis, primary sclerosing cholangitis, Caroli disease, or choledochal cysts.[6] The calculi are often isodense or slightly hyperdense to bile and often characteristically completely fill the ducts forming ductal casts.[1-8] With intravenous contrast administration, there may be enhancement in the surrounding liver parenchyma suggesting the presence of acute inflammation.[5] Gas may be seen within the ducts due to the bacterial infection or surgical intervention. Ultrasound will show similar findings with dilated ducts and frequently non-shadowing stones and debris. Gas within the ducts may greatly limit ultrasounds ability to evaluate the liver.[4,6]

CT is the best imaging modality for determining the extent of the disease, for surgical planning, and for follow-up. It can also evaluate for complications such as intrahepatic abscess formation. In addition, patients with RPC have an increased risk for cholangiocarcinoma, and this has been reported in up to 5% of patients.[1,3]

As RPC progresses, hepatic atrophy, cirrhosis, and portal hypertension can occur. Treatment for RPC includes antibiotic therapy, stone removal, biliary drainage, surgical resection, and eventually liver transplantation in end stage cases.

References:
1. Lim JH: Oriental cholangiohepatitis:Pathologic, clinical, and radiologic
features. AJR 1991;157:1-8.

2. Lim JH, Ko YT, Lee DH, Hong KS. Oriental cholangiohepatitis:Sonographic
findings in 48 cases. AJR 1990;155:511-514.

3. Okuno WT, Whitman GJ, Chew FS. Recurrent pyogenic cholangitis.
AJR 1996;167:484.

4. Jeffrey RB Jr. Diagnosis of interhepatic calculi and choledocholithiasis.
IN: Ferrucci JR, Mathieu DG, (eds): Advances in Hepatobiliary Radiology, St. Louis,
1990, C.V. Mosby Co.;347-366

5. Chan FL, Man SW, Leong LLY, Fan ST. Evaluation of recurrent pyogenic cholangitis with CT:
Analysis of 50 patients. Radiology 1989;170:165-169.

6. Kirby CL, Horrow MM, Kotlus-Rosenberg H, Oleaga JA. Ultrasound case of the day.
Radiographics 1995;15:1503-1506.

7. Baron RL. CT of the biliary tree. Radiologic Clin of N Amer 1991;21(6):1235-1250.

8. Federle MP, Cello JP, Laing FC, Jeffrey RB Jr. Recurrent pyogenic cholangitis in Asian
immigrants. Radiology 1982;143:151-156.

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Submitted by:
Thomas Herbener, M.D.
Sharyl P. Pickering, M.D.