Parasites and Biliary stones

Choledocholithiasis ٧٧
a specificity of 92%-100% in detecting choledocholithiasis (Hallal et al.,
2005). MRCP is also very useful in differentiating common hepatic duct
obstruction by Mirizzi syndrome from obstruction by gallbladder cancer
or enlarged lymph nodes (Hintze et al., 1997). MRCP is very useful for
ampullary tumours; it detects a dilated bile duct abutting on an irregular
ampullary mass indenting the duodenum. Although it can detect proximal
and body cancer of the pancreas, it offers no advantages over
CT/ultrasound in this respect, except in cystic tumours in view of its
ability to detect static fluid collections (Laubenberger et al., 1995 and
Cuschieri, 2002).
Cholangiography: This remains the criterion standard for the detection
of CBD stones. In the past, intravenous cholangiography was the only
available method for assessing the biliary tree, but the results had poor
accuracy and sensitivity, not to mention major concerns with allergic
reactions. Now intravenous cholangiography not used with the
introduction of endoscopic retrograde cholangiopancreatography (ERCP)
and percutaneous transhepatic cholangiography (PTC) (Dandan, 2005).
Endoscopic retrograde cholangiopancreatograph confirms the diagnosis
of choledocholithiasis as well as the location of the stone.(figure 16) This
procedure was initially employed in diagnosis, but today is most often
used as a therapeutic measure (Halpin et al., 2002).