Parasites and Biliary stones

Clonorchiasis ٢٨
2003). Ultrasonography is less useful in the differentiation between cured
clonorchiasis and active infection, since it reflects the pathological
changes in the bile ducts, which may persist for years after cure (Lee et
al., 1987 and Choi et al., 1999).
Computed tomography findings of clonorchiasis are essentially the
same as those observed by ultrasonography,which is mild, uniform
dilatation of the peripheral intrahepatic bile ducts without a focal
obstructing lesion. The extrahepatic duct has a normal diameter, and no
definite obstructing lesion is seen, even by thin-section helical computed
tomography (figure 10). These findings are considered pathognomonic
for clonorchiasis (Choi et al., 1988).
ERCP is useful in the diagnosis (Leung et al., 1988). Four ERCP
patterns have been observed: Diffuse tapering of the intrahepatic ducts
with dilatation of the intra- and extrahepatic ducts; a solitary cyst similar
to a liver abscess cavity or retention cysts; multiple cystic dilatations of
the intrahepatic ducts, mulberry-like appearance that is characteristic of
liver fluke infestation, and a combination of these findings, with
extensive cystic dilatation in some areas of the liver and biliary duct
ectasia in others (figure 11) (Lim, 1990).