Pulmonary trunk to ascending aorta ratio and reference values for diameters of pulmonary arteries and main bronchi in healthy adults

Objectives: The ratio of the diameter of pulmonary trunk (PT) to the diameter of the ascending aorta (AA) is used to evaluate cardiopulmonary diseases. Different values have been reported for the normal value of PT:AA ratio (to be less than 0.9, 1 or 1.4). In this study, we aimed to investigate the diameters of the PT, right (RPA) and left pulmonary artery (LPA), AA, right (RMB) and left main bronchus LMB) using multidetector computed tomography (MDCT) and to determine reference values for PT:AA according to age and sex in normal healthy adults. Methods: Thoracic CT images of 200 individuals, (103 males, 97 females; age 18–89 years), without cardiopulmonary pathology and surgery, were retrospectively evaluated using MDCT. Diameters of PT, RPA, LPA, AA were measured at the level of the pulmonary artery bifurcationand PT:AA ratio was calculated. Results: The mean diameters of PT, AA, RPA, LPA, RMB, LMB were found as 2.7±0.51 cm, 3.25±0.63 cm, 1.98±0.46 cm, 1.81±0.43 cm, 1.73±0.35 cm, and 1.66±0.55 cm, respectively. The mean value of PT:AA ratio was 0.84±0.18 cm in males and 0.86±0.13 cm in females. Conclusion: Determining the normal values of related measurements will contribute to diagnosis and treatment of cardiopulmonary diseases.