Pediatric liver transplantation has evolved into a life-saving procedure since the first successful transplant, for biliary atresia, in 1967. In the United States, biliary atresia remains the leading indication, accounting for nearly half of all pediatric liver transplants, with most recipients aged five years or younger. Advances in surgical techniques, particularly the development of split-liver and living-donor transplantation, have significantly improved graft availability and patient survival, achieving one-year survival rates as high as 94%. Despite these advances, post-transplant complications remain common and are broadly categorized as vascular, biliary, infectious, and parenchymal or neoplastic. Vascular complications pose the greatest threat to graft viability. Early postoperative imaging surveillance with grayscale and Doppler ultrasound is vital for timely detection. Normal early postoperative findings include mild perihepatic fluid, subtle vascular narrowing, and heterogeneous parenchymal echotexture. Typical Doppler characteristics include brisk systolic upstroke with continuous diastolic flow in the hepatic artery, monophasic flow in portal vein, and multiphasic or dampened venous waveforms. Hepatic artery thrombosis is the most critical vascular complication, often manifested as tardus-parvus arterial waveforms, and can lead to graft ischemia or failure. Hepatic artery stenosis, occurring most often within the first 100 days, may require prompt endovascular intervention. Portal vein thrombosis or stenosis, though less frequent, can cause portal hypertension with splenomegaly and ascites. Biliary complications, including anastomotic strictures and leaks, affect approximately 12–40% of pediatric recipients, usually within the first three months post-transplant. In the longer term, neoplastic complications such as post-transplant lymphoproliferative disorder occur in up to 2-8%of pediatric liver transplant patients, necessitating vigilant radiologic and clinical follow-up. Ultrasound remains the cornerstone of early and serial postoperative evaluation, given its safety, accessibility, and high sensitivity for vascular and biliary pathology. Rapid identification of complications enables timely intervention, optimizing graft function and long-term survival in pediatric liver transplant recipients. Read More

Meeting name: SPR 2026 Annual Meeting , 2026

Authors: Kumar Tushar, Noda Sakura, Kim Helen Hr

Keywords: Hepatic Transplant, Transplant Interventions, Ultrasonography

A whirlpool describes rotating water created by opposing currents or upon an encounter with an obstacle. On imaging, it refers to a twist of the vascular pedicle of an organ, with a subsequent characteristic appearance on color Doppler images. Multiple abdominal pediatric emergencies are associated with a whirlpool sign, including midgut and other intestinal volvulus, testicular torsion, and ovarian torsion. This exhibit aims to review the underlying embryologic mechanism predisposing to this characteristic appearance, the role of this sign in the diagnosis of these conditions, the supporting imaging features that can help further define the diagnosis, as well as some pitfalls and differential diagnoses that can lead to a fallacious diagnosis. Read More

Meeting name: SPR 2022 Annual Meeting & Postgraduate Course , 2022

Authors: Aboughalia Hassan, Oztek Murat Alp, Noda Sakura

Keywords: Whirlpool sign, Midgut malrotation, Testicular torsion