Normal mediastinal and hilar lymph nodes in children on multi-detector row chest computed tomography

Objective To study normal mediastinal and hilar lymph nodes on multi-detector chest computed tomography (CT). Methods A cohort of 120 children aged 1-17 years underwent emergency CT, including the chest, after high-energy trauma. Axial 5-mm reconstructions were evaluated for lymph nodes at hilar and various mediastinal levels and the short-axis diameters were measured. Results At least one lymph node was found in 115 (96%) children, with subcarinal (69%), lower paratracheal (64%) and hilar (60%) nodes being most common. Up to 10 years of age most lymph nodes were smaller than or equal to 7 mm. In older children lymph nodes measuring up to 10-mm-short-axis diameter were found. Lymph nodes were rare along the mammary vessels, at lower oesophageal and at prevascular and posterior mediastinal levels in children. Conclusion Mediastinal and hilar lymph nodes are more common than previously thought, probably because of increased detection by modern multi-detector CT. Lymph node location and age have to be taken into account when evaluating lymph nodes in the paediatric chest. Key Points The size and location of normal lymph nodes is of great diagnostic importance There is little relevant published information related to pediatric chest computed tomography We provide normative data concerning mediastinal and hilar lymph nodes in children These normal values can help identify abnormal lymph nodes in children.