Evaluation of Aortic and Pulmonary Artery Diameters Using Computed Tomography Angiography

Objective: The truncus pulmonalis, the main pulmonary artery (MPA), originates from the right ventricle at the level of the upper edge of the left third rib cartilage and carries blood to both lungs. After a short course, it branches into two arteries beneath the aortic arch: the right pulmonary artery (RPA) and the left pulmonary artery (LPA). The aorta, the main artery that carries blood to the body, originates from the left ventricle. It is divided into three sections: the ascending aorta (AA), the aortic arch, and the descending aorta. Methods: Between January and December 2023, the files of adult patients who were suspected of having pulmonary embolism and who underwent thoracic CT angiography (CTA) at the Erzincan Mengücek Gazi Training and Research Hospital Emergency Department were reviewed. The patients’ DICOM-format images were exported. These images were uploaded to the 3D-Slicer (version 5.10.0 for Windows) and the MPA, RPA, LPA, and AA diameters were measured in the axial plane. The MPA-to-AA diameter ratio was calculated for each patient and designated PA:A. Results: This study included 52 men and 50 women, for a total of 102 patients. The patients’ average age was 67. No significant difference in vessel diameters was observed between genders. AA, MPA, RPA, and LPA diameters were higher in the >67 age group than in the ≤67 age group. There was no significant difference in the PA:A ratio between age groups. A positive, moderate, and statistically significant correlation was found between age and the diameters of AA, MPA, RPA, and LPA. No significant correlation was found between age and the pulmonary artery-to-aorta (PA:A) ratio. A strong, positive, and statistically significant correlation was found between MPA diameter and the diameters of RPA and LPA. A positive, moderately significant correlation was found between MPA diameter and AA diameter. A strong, significant positive correlation was found between RPA diameter and LPA diameter. Conclusion: Aortic and pulmonary artery diameters have been evaluated using various methods in previous studies. To better understand the clinical importance of aortic and pulmonary artery diameters in cardiopulmonary diseases, it is necessary to know their normal reference values. The Framingham Heart Study reported an average MPA diameter of 25.1 mm and an average PA:A ratio of 0.77. In our study of the Turkish population, the mean AA, MPA, RPA, and LPA diameters were 34.1 mm, 25.9 mm, 21.1 mm, and 20.2 mm, respectively, and the PA:A ratio was 0.78. Further studies in larger populations are needed to establish reference values for aortic and pulmonary artery diameters in healthy individuals.