Purpose or Case Report: Proficiency in intra-abdominal pediatric vascular ultrasound is essential for all pediatric radiologists. Command of spectral Doppler findings is vital in identifying early abdominal vascular pathology, particularly in the evaluation of pediatric patients with liver disease or following orthotopic liver transplantation. The following is a condensed review of normal and abnormal abdominal vascular ultrasound with emphasis on liver disease and the posttransplant pediatric patient.
Methods & Materials: A thorough literature review of sonographic findings in normal pediatric abdominal vasculature, liver disease, and hepatic transplantation was performed. Components of the spectral waveform in normal and abnormal main intra-abdominal arteries and veins were critically appraised. Vascular characteristics and correlative images in cirrhosis are summarized, as are indications for hepatic transplantation. Finally, sonology in the pediatric liver transplant patient is described in a pictoral fashion, including a chronologic description of postoperative complications.
Results: With the exception of premature and term neonates, normal pediatric vascular abdominal ultrasound is similar to findings in adults. Differences seen in neonates can be explained by the inverse relationship between vessel size and vascular resistance, with vascular resistance increasing exponentially with decreasing vessel radius. In children, the leading cause of cirrhosis is biliary atresia, for which hepatic transplantation is the only cure. Pretransplant evaluation in these patients requires scrutiny of the intra-abdominal vasculature, characterization of portosystemic collaterals, and assessment of hepatic lesions. The sonologist should be familiar with the Milan criteria, which are used in the determination of a patient's eligibility for transplantation. Transient, expected vascular abnormalities may mimic developing stenoses or thromboses in the immediate post hepatic transplantation period. Knowledge of the typical vascular complications after hepatic transplantation, and the timeframe during which each occurs, guides the interpretation of abdominal Doppler ultrasound.
Conclusions: Abdominal Doppler is the primary diagnostic imaging modality for pediatric patients with suspected or known abdominal vascular and liver disease. A comprehensive knowledge of abdominal Doppler is paramount in diagnosis of pediatric liver disease and post transplantation complications.