GROWTH-ADJUSTED MPA/AA ratio reference values could help place paediatric chest CT findings into a developmental context, according to a multicentre retrospective study. Reference Values Reflected Normal Childhood DevelopmentThe investigators sought to establish growth-adjusted reference values for the paediatric MPA/AA ratio using clinically indicated chest CT scans and to assess their haemodynamic applicability in a separate right heart catheterisation cohort. An age-based, sex-adjusted unified model was developed to generate growth-adjusted reference values. The researchers said future paediatric studies should investigate whether combining the MPA/AA ratio with other CT-derived measurements could further improve diagnostic performance. Growth-adjusted reference values for the main pulmonary artery-to-ascending aorta ratio derived from clinically indicated chest CT in children.