Purpose or Case Report: Gadoxetate disodium-enhanced MRI abdomen is the imaging of choice for evaluation of liver lesions. However, in patients with underlying liver dysfunction, uptake and excretion of the hepatobiliary contrast agent is impaired; standard 20-minute delay hepatobiliary phase imaging may be insufficient to characterize hepatic lesions of interest. Our study aims to evaluate the adequacy of standard 20-minute delayed phase hepatobiliary imaging after gadoxetate disodium administration in pediatric patients with liver dysfunction. A secondary objective is to assess the utility of hepatic function laboratory values as a screening tool to identify patients with impaired hepatobiliary excretion in whom hepatobiliary phase imaging at 20 minutes may be inadequate.
Methods & Materials: In this single-institution retrospective study (2015-2025), gadoxetate disodium-enhanced abdominal MRI reports were queried using the terms “cirrhosis,” “Kasai,” “Fontan,” and “liver failure.” 50 pediatric patients (mean age 13.8 years, range 2-20 years; 27 females) with hepatic disease were selected from 62 gadoxetate disodium-enhanced abdominal MRI exams. Hepatobiliary excretion at 20-minute delay (HBP20) was categorized as either visualized or non-visualized. Hepatic function laboratory values obtained closest to the time of MRI were recorded and correlated with hepatobiliary excretion status.
Results: 5 of 50 examinations (10%) had inadequate imaging at HBP20. These patients included those with biliary atresia post-Kasai procedure (n = 2), congenital heart disease post-Fontan (n = 1), and liver failure due to other causes (n = 2). Among hepatic function tests, serum total bilirubin demonstrated the strongest association with non-visualized hepatobiliary excretion at HBP20. Using a 2.0 mg/dL cutoff, total bilirubin was 90% accurate, with 100% sensitivity and 89% specificity for predicting non-visualized hepatobiliary excretion at 20 minutes.
Conclusions: Serum total bilirubin may be an effective and inexpensive screening tool for predicting non-visualized hepatobiliary excretion at 20-minute delay imaging in pediatric patients with liver dysfunction. Patients with elevated bilirubin may benefit from extended delayed imaging to optimize hepatobiliary contrast uptake and ensure accurate liver lesion characterization. Integrating bilirubin screening into MRI protocols could improve diagnostic yield and characterization of hepatic lesions in this high-risk pediatric population.