99mTc sestamibi imaging - can it be a useful substitute for hepatobiliary scintigraphy in infantile jaundice?

AIM Hepatobiliary scintigraphy is an integral part in the diagnostic work-up of the neonatal cholestasis syndrome. However, less than optimal specificity is its major disadvantage. Differentiation between biliary atresia and neonatal hepatitis is nearly impossible in some cases with poor hepatocellular function. 99mTc sestamibi (MIBI) is a cationic lipophilic agent which is a substrate of P-glycoprotein. This glycoprotein is normally expressed in biliary canalicular surfaces of hepatocytes. This property provides a hepatic excretory mechanism which is different from bilirubin excretion. In this study we evaluated the value of 99mTc MIBI in differential diagnosis of neonatal cholestasis. PATIENTS, METHODS 20 infants with a mean age of 2.41 months (range, 0.1-5 months) were included in the study. Ten infants turned out to have extrahepatic biliary atresia and the other ten had neonatal hepatitis. Hepatobiliary (with 99mTc BrIDA) and 99mTc MIBI scintigraphy were performed for all the patients. RESULTS 99mTc MIBI scintigraphy has shown bowel activity in all patients, including the patients with biliary atresia. Hepatobiliary scintigraphy revealed bowel activity only in five patients with neonatal hepatitis. CONCLUSION Bowel visualization with 99mTc MIBI may be seen in patients with biliary atresia and 99mTc MIBI has limited value in differential diagnosis of neonatal cholestasis.