SPECT Nuclear Imaging: Improved Diagnostic Tool in Infants With Biliary Atresia

Abstract

Introduction: Biliary atresia is an idiopathic disorder characterized by progressive obliteration of the biliary system in infancy and is the most common indication for liver transplant in children. Conventional nuclear hepatobiliary scanning (CN) is used in the evaluation of infants with neonatal cholestasis to identify biliary atresia and to proceed with more invasive diagnostic testing. Three-dimensional singlephoton emission computed tomography (SPECT) nuclear scan removes out of plane information using a gamma camera that rotates around the patient and may increase diagnostic accuracy when augmented to CN imaging. Limited data is known pertaining to the utility of SPECT as a single diagnostic modality in neonatal cholestasis. The study objective was to compare SPECT with CN imaging in the investigative work-up of infants with neonatal cholestasis to identify biliary atresia. Methods: Infants with unexplained neonatal cholestasis were included. All were pretreated with phenobarbital for 5 days prior to nuclear hepatobiliary imaging technique. Clinical and biochemical parameters analyzed were: age at time of scan, gender, anthropometric data, standard liver function tests, coagulation tests, nuclear medicine scan modality and study time. Nuclear imaging techniques were compared. A Student t test was used to compare groups. Results: The study group consisted of 17 patients (9 females). Demographic, clinical and biochemical parameters including weight, age, AST, ALT, GGT, total bilirubin, direct bilirubin and prothrombin time were statistically similar between the CN and SPECT groups. All patients underwent CN; 8 had both CN and SPECT performed (Table 1). Biliary atresia was diagnosed in 10 patients; idiopathic neonatal cholestasis in 4 patients; Alagille syndrome in 1 patient; delta-F508 cystic fibrosis in 1 patient; and TPN cholestasis in 1 patient.Table 1: Study ResultsConclusion: Three-dimensional SPECT nuclear hepatobiliary imaging demonstrates significantly reduced study time and exhibits comparable diagnostic accuracy as conventional nuclear hepatobiliary imaging in the work-up of cholestatic infants with suspected biliary atresia. These results suggest that SPECT may be used alone in identifying infants with biliary atresia with significant reduction in study time. Further studies are warranted to confirm these findings.