Pediatric thoracic aorta: normal measurements determined with CT.

Normal thoracic aortic dimensions in adults have been established by means of computed tomography (CT), but such measurements are not available in children. To establish normal standards, contrast material-enhanced chest CT scans of 117 children and adolescents, ranging in age from 2 weeks to 19 years, were reviewed retrospectively. Patients with congenital heart disease, vascular anomalies, renal disease, hypertension, and connective-tissue disorders were excluded, resulting in 97 studies. Diameters of the thoracic aortas were measured at three levels. Interobserver and intraobserver variances were determined. A direct linear relationship to patient age was observed, and regression analysis was performed. These standards help in differentiating the normal from the abnormal aorta on chest CT scans of children.