False-negative Hepatobiliary Scintigraphy for Biliary Atresia / 대한핵의학회잡지

We present the case of a patient with biliary and duodenal atresia who showed false-negative hepatobiliary scintigraphy results. The patient was born at 37 weeks and 2 days of gestation. Her mother had undergone amnioreduction after detection of a double-bubble ultrasound sign in the fetal abdomen. At 2 days of age, total serum bilirubin level was elevated. On hepatobiliary scintigraphy 4 days later, the gallbladder was visualized from 30 min and it showed duodeno-gastric reflux at 240 min. After 24 h, the radiotracer was almost washed out in the hepatic parenchyma, but there was retention in the gastroduodenal junction. Because the biliary to duodenal transit was visible, biliary atresia seemed unlikely. Abdominal ultrasonography at 7 days of age showed a small dysmorphic gallbladder, but triangular cord sign was not definite. Magnetic resonance cholangiography revealed atretic gallbladder. Although cystic and common bile ducts were visible, the proximal common hepatic bile duct was not visible. The next day, serum total bilirubin levels remained elevated (17.1 mg/dl) with direct bilirubin level of 1.2 mg/dl. Kasai portoenterostomy with duodeno-duodenostomy was performed at 10 days of age. Histopathological evaluation showed a fibrous obliteration of the common bile duct, consistent with that of biliary atresia.

Utility of Tc99m-Mebrofenin hepato-biliary scintigraphy (HIDA scan) for the diagnosis of biliary atresia.

Aim: To determine the utility of Tc99m-Mebrofenin hepato-biliary scintigraphy (HIDA scan) for diagnosis of biliary atresia in patients with neonatal cholestasis. Methods: Our study involves the retrospective analysis of 46 patients with neonatal cholestasis who underwent HIDA scans at the Pediatric Hepatobiliary Clinic, BJ Wadia Hospital for Children from May 2005 to July 2007. Biliary atresia (BA) was diagnosed on the basis of intra-operative cholangiogram. Non-BA patients were included in the neonatal hepatitis (NH) group. All patients received phenobarbitone and ursodeoxycholic acid for 5 days, prior to the HIDA scan. The HIDA scan was evaluated on the basis of uptake of the radioactive tracer by the liver at 5 minutes after intravenous injection; retention of radioactive tracer within the liver at 24 hours after injection and visualization of excretion of tracer into the intestine upto 24 hours after administration. The results of the HIDA scans were analyzed and correlated with the final diagnosis, gender and age of the patients. Chi-square test was employed for statistical analysis. Results: The age of presentation of our patients ranged from 5 days to 6 months. The male: female ratio was 37:9. Of the total 46 patients, 28 had BA and 18 had NH. All 28 (100%) patients diagnosed with BA showed persistent radiotracer in the liver at 24 hours whereas 17 (94.4%) of the 18 NH patients showed hepatic radiotracer retention (p=0.207), the difference being statistically insignificant. Twenty two (78.6%) patients of BA showed no excretion of the radiotracer at 24 hours whereas only 7 (38.9%) of the NH group did not excrete the radiotracer (p=0.007), which was statistically significant. Neither the sex nor the age of the child contributed to any difference on the hepatic retention (p=0.618 and 0.235, respectively) or on the intestinal excretion (p=0.307 and 0.9, respectively) of the radiotracer. Conclusion: HIDA scan is a useful tool for screening of biliary atresia in patients with neonatal cholestasis. Non excretion of the radioactive radiotracer into the intestines even after 24 hours of radiotracer administration can suggest biliary atresia in majority of patients.