Diameters of normal thoracic vascular structures in pediatric patients

Purpose To determine the normal range of aortic and pulmonary artery diameters on chest CT, and to search a constant ratio when the diameters of thoracic vascular structures are compared with an internal reference. Methods Contrast-enhanced chest CT scans of 133 pediatric patients were retrospectively evaluated. Diameters of ascending and descending aorta, main pulmonary artery, right and left pulmonary arteries and a constant thoracic vertebra were measured. The mean ratios of thoracic vascular diameters to the diameter of the thoracic vertebra were calculated. Results There was a positive correlation between the age of the patients and vascular diameters. The mean ratios of vascular diameters to the diameter of thoracic vertebra, ranged from 1.1 for the ascending aorta to 0.70 for the right and left pulmonary arteries, were consistent. Conclusions Diameters of thoracic vascular structures increase with age. The consistent vertebral to vessel ratios can be useful in evaluation of chest CT of pediatric patients.