Bile duct dilation

Teefey, S., Baron, R.L., Schulte, S.J., Patten, R.M., Molloy, M.H. Patterns of intrahepatic bile duct dilatation at CT correlation with obstructive disease processes. Radiology 1992 182 139—142... 

A drastic reduction in numbers of interlobular bile ducts is termed ductopenia (or paucity of bile ducts). Ductopenia is considered to be present if the ratio of interlobular ducts to the number of portal tracts is <0.5 (normal value 0.9-1.8), i.e. in a sufficiently large biopsy specimen, no more than half of the portal fields should be without a bile duct. Ductopenia can appear as an isolated defect (non-syndromic) or in combination with other extrahepatic (syndromic) anomalies. Non-syndromic paucity constantly exhibits bile-duct dilatation with blunting of microvilli. Idiopathic neonatal hepatitis sometimes overlaps with non-syndromatic ductopenia. Children with ductopenia may survive into adulthood. (504) (s. fig. 32.16)... 

In 27 patients who received intrahepatic floxuridine, total dose 20-41 mg/kg extrahepatic biliary sclerosis was discovered by CT scan and ultrasound, followed by endoscopic retrograde cholangiopancreatography and/or percutaneous cholangiography in three cases (4). Radiological findings included complete obstruction of the common hepatic duct in one case, common hepatic duct stenosis in two cases, common bile duct obstruction in one case, and intrahepatic bile duct dilatation without identifiable obstruction in one case... 

Two patients became jaundiced 1 and 3 months after RE and imaging showed intrahepatic bile duct dilation. In the first case, dilation was limited to... 

Any available US or CT images should be reviewed before the procedure to confirm the presence of bile duct dilation. If dilated ducts are confined to a single lobe, percutaneous cholangiography should be performed via that lobe. 

Sonograms of the liver may show, besides bile duct dilatations, intraluminal bulbar protrusions, bridge formation across dilated lumina, and portal radicles partially or completely surrounded by dilated bile ducts (Marchal et al. 1986). The chol-angiographic features of Caroli s disease are well established as saccular or fusiform dilatation of the intrahepatic bile ducts. Irregular bile duct walls, strictures, and stones may be present (Lucaya et al. 1978). Segmental ductal dilatation is more common than diffuse ductal dilatation. Alternating areas of... 

On US, intraductal-growing CCA presents with focal, segmental or diffuse bile duct dilatation with single or multiple papillary intraductal masses or without visible tumour. An intraductal mass appears as a well-... 

Intraductal CCA at the hilum also manifests as an intraductal soft-tissue mass but is associated with more diffuse bile duct dilatation. At this location, the tumours are frequently multiple or disseminated within the biliary system and involve both the intrahepatic and extrahepatic bile ducts. Therefore, the true extent of this superficially spreading tumour is difticult to determine. HCC occasionally invades and grows within the bile duct. This tumour appears at imaging as a polypoid mass expanding the bile duct and therefore is difficult to differentiate from intraductal-growing CCA. 

In general, activation of alpha-1 adrenergic receptors causes a contraction of smooth muscle and of blood vessels, pilomotor muscles, dilator pupillae, vas deferens, nictitating membrane, splenic capsule, and sphincters of the intestine and urinary bladder and of the bile duct. An exception is the relaxation of the smooth muscle of the intestine. Prazosin [19216-56-9] indoramin [26844-12-2] and WB-4101 are relatively selective antagonists of these receptors. 

Dilatation of both the intrahepatic and extrahepatic ducts and the common bile duct is clearly seen by ultrasound, indicating obstruction, e.g. by gallstones or tumour. 

Varices Ultrasound scan -Doppler Dilated bile ducts... 

Fig. 6.9 Blockage and dilation of the intrahepatic bile ducts ( lakeland plain ) in obstructive jaundice...

Songur, Y., Temudn, G., Sahin, B. Endoscopic ultrasonography in the evaluation of dilated common bile duct. X Clin. Gastroenterol. 2001 ... 

We regard stasis in dilated bile ducts as a contraindication of biopsy, although there are controversial views in the literature concerning this point. (108, 151) The risk of biliary complications should not be underestimated, especially since new examination techniques have indeed... 

Caroli s disease presents with multiple tubular structures, which correspond to focal cystic dilations of large interlobular bile ducts. The reduced density values of... 

Obstruction of a large bile duct leads to dilated intrahepatic bile ducts, which appear on CT scans as ramified linear or rounded structures with bile-equivalent density. Their luminal diameter increases progressively in the direction of the hilus. (47) Segmental dilation of the bile ducts may be indicative of a tumour. A dilation of the bile duct of >9 mm points to a peripheral obstruction, mostly near the papilla of Vater. 

This form of jaundice is initiated by a mechanical obstruction in the region of the extrahepatic or intrahepatic bile ducts, which is why the terms mechanical jaundice or obstructive jaundice are also common. The congestion of the bile flow is either incomplete or complete. Bile stasis results in dilation of the extrahepatic and intrahepatic bile ducts, allowing hepatomegaly to develop. (8, 9, 16, 19) (s. tab. 12.1)... 

Ultrasound examination is always indicated for the clarification of jaundice. The results determine the subsequent diagnostic steps. It is important to clarify whether the bile ducts are dilated, which is a hint for obstructive jaundice, (s. tabs. 6.8, 6.9) (s. p. 131)... 

ERC facilitates precise visualization of the bile ducts - this is also possible by means of PTC in cases of sonographically determined dilation of the bile ducts with suspected biliary obstruction. PTC is likewise indicated if ultrasound examination fails to produce evidence of enlarged bile ducts and/or ERC has proved inconclusive even though clinical and laboratory examinations suggest biliary obstruction, (s. pp 183, 184)... 

Morphology The morphologist uses the term cholestasis to describe the presence of bile in the hepatocytes as well as in hypertrophic Kupffer cells (= cellular bilirubino-stasis), particularly in the form of inspissated bile droplets and copper within the more or less dilated canaliculi (= canalicular bilirubinostasis). In extrahepatic cholestasis, bile is additionally found within the likewise mostly dilated interlobular bile ducts (= ductular bilirubinostasis) as well as in the parenchyma in the form of bile infarcts" or bile lakes . 

In the case of non-dilated bile ducts, further specific laboratory parameters may be necessary for differential diagnosis, such as electrophoresis, immunoglobulins, hepatitis serology (s. p. 116) and tti-foetoprotein (s. p. 106). Determination of the AMA should always be considered. (s. p. 120) (s. tabs. 5.19-5.21 13.7)... 

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