Airway and chest ultrasonography in pediatric patients encompasses a wide spectrum of diagnostic applications, broadly categorized into evaluation of vocal cords, trachea, lungs, diaphragm, and pleura. Vocal cord ultrasonography is increasingly employed for the assessment of vocal cord motion and detection of palsy, particularly in post-intubation or postoperative settings. Tracheal ultrasonography represents an evolving field, currently utilized at our institution for identification of tracheal cartilaginous sleeve—a condition characterized by replacement of segmented tracheal rings with a continuous cartilaginous sheath, often associated with craniosynostosis syndromes. Lung and pleural ultrasonography are well-established techniques increasingly familiar to radiologists and can be useful for evaluating a wide range of pathologies, including consolidation, edema, fibrosis, interstitial pneumonia, lung abscess, pleural effusion, empyema, pneumothorax, and lung tethering. Diaphragmatic ultrasonography is also routinely performed to assess diaphragmatic motion abnormalities such as paralysis, paresis, and eventration—conditions that can be challenging to differentiate by radiograph. A solid understanding of normal lung, pleural, airway, and diaphragmatic anatomy, along with mastery of proper sonographic technique, is essential for accurate diagnosis and interpretation across all levels of radiology practice. As air-filled lungs limit acoustic penetration, radiologists must also recognize common pitfalls and artifacts encountered in pediatric chest ultrasound, including reverberation artefacts, B-lines, M-mode artifacts, and misinterpretation of peritoneal fluid as effusion. Although radiography remains the first-line modality for thoracic evaluation, its utility is constrained by complex, overlapping anatomy of the mediastinum and hidden pulmonary areas. Computed tomography (CT), while diagnostically powerful, exposes young patients to ionizing radiation and should be reserved for cases in which sonography and radiography are inconclusive. This educational exhibit aims to highlight optimal techniques, review relevant anatomy, and illustrate the spectrum of airway and chest pathologies detectable by ultrasound. It further emphasizes recognition of artifacts and comparison with radiographic and CT findings, with goal to promote use of ultrasonography as a radiation-free, readily accessible, and accurate diagnostic tool for pediatric thoracic evaluation. Read More

Meeting name: SPR 2026 Annual Meeting , 2026

Authors: Kumar Tushar, Romberg Erin, Otjen Jeffrey

Keywords: Chest, Ultrasound, Dynamic Ultrasound

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

Dynamic and four-dimensional computed tomography (4D-CT) of the airways and lungs is an advanced imaging technique designed to identify dynamic pathologies across various levels of airway, including the oropharynx, larynx, trachea, bronchi, and lungs. This modality enables detailed assessment of airway motion and functional abnormalities that are intermittently absent on conventional static imaging. At the oropharyngeal level, Robin sequence (Pierre Robin syndrome) represents congenital anomalies resulting from abnormal development of the first pharyngeal arch, leading to mandibular hypoplasia, failure of normal tongue descent, non-fusion of the palatal shelves, and resultant upper airway obstruction. At the laryngeal level, vocal cord dysfunction is a cause of feeding difficulties and vocal dysfunction in the pediatric population, most frequently resulting from prolonged intubation or iatrogenic injury to the recurrent laryngeal nerve following cardiac surgery. In such cases, dynamic CT serves as a valuable, non-invasive alternative to nasal endoscopy for evaluating glottic motion. Tracheomalacia, defined as excessive expiratory collapse of the tracheal lumen, may be congenital—such as with cystic fibrosis or Mounier-Kuhn syndrome—or acquired secondary to prolonged intubation, chronic or recurrent infections, or idiopathic. Similarly, bronchomalacia refers to the weakening of bronchial cartilage, resulting in airway collapse or significant luminal narrowing during expiration, and may also occur congenitally or as a sequela of chronic inflammation. Dynamic CT of the lung parenchyma can demonstrate areas of air trapping during the expiratory phase, such as with bronchiolitis obliterans secondary to recurrent inflammation, although the precise clinical implications of the CT findings remain undefined. Importantly, many of these entities are challenging to detect on traditional inspiratory and expiratory CT imaging. Dynamic low-dose CT protocols not only enhance diagnostic accuracy by providing real-time functional assessment but also reduce overall radiation exposure by eliminating the need for separate phase acquisitions. This pictorial essay aims to review the spectrum of airway and lung pathologies detectable by dynamic and 4D-CT, emphasizing optimal imaging techniques, interpretative considerations, and risk-based diagnostic strategies relevant to pediatric radiologists. Read More

Meeting name: SPR 2026 Annual Meeting , 2026

Authors: Kumar Tushar, Romberg Erin, Otjen Jeffrey

Keywords: 3D Imaging, Airway, CT Dynamic Airways

Sinusoidal obstruction syndrome (SOS), also known as veno-occlusive disease (VOD), is a potentially life-threatening hepatic complication that occurs primarily following hematopoietic stem cell transplantation (HSCT). It is characterized by obstruction of hepatic sinusoids and venules due to accumulation of cellular debris and red blood cells, leading to impaired hepatic outflow. The incidence in pediatric patients can be as high as 40%, resulting from toxic injury or activation of liver sinusoidal endothelial cells (LSECs). Common etiologic factors include myeloablative conditioning regimens for HSCT, chemotherapeutic agents such as oxaliplatin, and total body irradiation. SOS/VOD is classified into acute (80%, within 21 days post-HSCT) and late-onset forms (20%, beyond 21 days). Histopathologically, late-phase SOS shows peri-sinusoidal fibrosis and hepatocyte atrophy in addition to sinusoidal obstruction. Clinically, the disease manifests with painful hepatomegaly, conjugated hyperbilirubinemia, and rapid weight gain or ascites. While the modified Seattle and Baltimore criteria are traditionally used for adults, the European Society for Blood and Marrow Transplantation (EBMT) 2019 criteria have been specifically developed for the pediatric population, incorporating both clinical and radiologic parameters. Ultrasonography remains the first-line imaging modality, including gray-scale, color Doppler, and spectral analysis. Ultrasound elastography can detect SOS as early as 2–12 days before clinical criteria are met by quantifying increased hepatic stiffness due to portal hypertension; a ≥ 30% rise in stiffness from baseline has demonstrated high sensitivity and specificity. Characteristic sonographic findings include hepatomegaly, gallbladder wall thickening, increased portal vein diameter, ascites, paraumbilical vein visualization with altered flow, reduced portal venous velocity, and elevated hepatic artery resistive index—imaging parameters that are incorporated into the newer Hok-US scoring system (maximum 14 points). Additionally, MR elastography and hepatobiliary MRI using Eovist have shown promise for early, noninvasive detection. Early diagnosis is critical, as severe SOS carries mortality rates up to 80%, and the only approved therapy remains defibrotide, emphasizing the need for vigilant imaging surveillance and prompt management. Read More

Meeting name: SPR 2026 Annual Meeting , 2026

Authors: Kumar Tushar, Elhussein Wala, Kim Helen Hr

Keywords: Abdominal Imaging, Venoocclusive Disease, Sinusoidal Obstruction Syndrome