الفهرس 
Aim of the workOnly 14 pages are availabe for public view
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Abstract
Real-time abdominal ultrasonography is the most useful initial imaging study in the evaluation of pediatric cholestasis. Ultrasonography can assess the size and appearance of the liver and gall bladder including visualization of gallstones and biliary sludging. An ultrasound examination can establish the diagnosis of choledochal cyst or demonstrate a small or absent gall bladder that suggests biliary atresia. The triangular cord sign that represents a fibrous core of tissue at the porta hepatis is highly sensitive for biliary atresia. Magnetic Resonance Cholangiography is being increasingly used to assess the biliary tract. Non visualization of the common bile duct and presence of small gall bladder have been noted in biliary atresia. Computed tomography can detect air in the gallbladder wall or lumen, irregular gallbladder wall and lack of gallbladder wall enhancement. CT can detect enlarged lymph nodes in the porta hepatis, abdominal cavity or in the retroperitoneal space and distant metastasis. Although the imaging features of liver tumors often overlap, there is specific CT imaging findings that can help distinguish particular entities. Helical CT cholangiography using an oral or intravenous biliary contrast agent is a feasible technique: It is well tolerated by patients, inexpensive and easily applied to current technology. Hepato biliary scintigraphy using technetium labeled imino diacetic acid derivatives is helpful in distinguishing biliary atresia from other causes of cholestasis. This test is highly sensitive for biliary atresia but the specificity is low because the excretion of the isotope may be delayed in certain forms of intrahepatic cholestasis as well. In biliary atresia the uptake of isotope into the hepatocyte is normal but the excretion is delayed or completely absent. X-Ray has a limited role in the confirmation of obstructive jaundice related to gallbladder stones. Percutaneous liver biopsy is the single most definitive investigation in the evaluation of pediatric cholestasis. Tumors tissue characterization and the characteristic findings in biliary atresia include bile duct proliferation, bile plugs and portal tract edema and fibrosis. These findings should be differentiated from those seen in idiopathic neonatal hepatitis that includes diffuse cell swelling, giant cell transformation and focal hepatocellular necrosis. Liver biopsy can also demonstrate viral inclusion bodies suggesting cytomegalovirus or herpes simplex infection. Liver biopsy can be supported by CT and US. ERCP continues to be an established and effective means for diagnosing and treating biliary obstruction as choledocholithiasis and stricture sclerosing cholangitis. However, the need for high technical expertise and general anesthesia for the study limits its feasibility in pediatric cholestasis. It appears that new radiological imagings are important for the early diagnosis of the different causes of pediatric jaundice. Radiological investigations of pediatric jaundice is in a highly progress. Chosen the safest, the most rapid, simple and even cheap imaging technique is the target to find the cause of jaundice in short systemic pathway.