Pulmonary Artery Diameter: Means and Normal Limits: Assessment by Computed Tomography Angiography

Background: Normal pulmonary artery (PA) diameter remains blurred and the definitions of PA aneurysm are heterogenous. We aimed to assess PA diameters, identify a threshold for normal diameters as well as to define PA aneurysms, possible predictors of PA size and evaluate the correlation with mid-ascending aortic diameters.

Method: Between 04/2018 and 08/2019, a total of 497 consecutive patients who underwent whole-body computed tomographic angiography were reviewed. Clinical and imaging data were collected from our institutional database. Precise three-dimensional centerline measurements were taken. Linear regression analysis was performed to detect parameters associated with PA diameter. A 2-stage model was created to identify potential predictors and afterwards the resulting statistically significant interactions were tested. Data was grouped and PA, standard deviation, and upper normal limits were calculated.

Results: Among 497 patients with an average age of 51.4 ± 20.2 (74.6% males), mean PA diameter measured 32.0 ± 4.6 mm (female: 31.2 ± 4.7 mm vs. male: 32.2 ± 4.5 mm; p = 0.032). Mean PA length, left PA, and right PA diameters were similar between male and female patients. We found a significant correlation (r = 0.352; p < 0.001) between the PAs and mid-ascending aortic diameters. BSA (p = 0.032, HR: 4.52 [0.40; 8.64] 95% CI) was the only significant predictor for PA diameter.

Conclusion: Assessing PA diameter by taking three-dimensional centerline measurements in a representative patient cohort after contrast-enhanced, whole-body computed tomography is a very precise method by which to define normal PA diameters. Normal mean PA diameter is 32.0 (SD 4.6) mm. BSA proved to be the only predictor of pulmonary trunk diameter. The normal diameters and corresponding upper limits of normal measured in this study reveal that our definition of the pulmonary artery aneurysm's threshold should not be less than 45 mm. We also discussed the indications and surgical treatment options for PAA that effectively reduce the risk of subsequent complications.

Publication History

Article published online:
03 February 2022