Prediction of COPD using CT measurements of pulmonary artery and aortic diameter

Introduction: Chronic obstructive pulmonary disease (COPD) is group of progressive lung disease which commonly includes emphysema and chronic bronchitis. Among non-communicable disease, COPD is estimated to be second largest cause of death in India. Computed Tomography (CT) of chest and measurements of arteries could be simple and effective modality for diagnostic evaluation of COPD. Aim: To determine whether CT measurements such as Pulmonary artery and aortic artery diameters are useful in predicting COPD. Materials and Method: A total of 291 patients was included in this retrospective study who had underwent CT thorax from April 2016 to April 2018. 194 patients with COPD were taken as cases and 97 patients without any history of COPD were taken as controls. Diameters such as Main pulmonary artery (MPA), right pulmonary artery (RPA), left pulmonary artery (LPA), ascending aorta (AAo) and descending aorta (DAo) was measured on an axial CT thorax image. Ratios of MPA/AAo and MPA/DAo were also calculated. Mann Whitney U test was used to compare CT measurements between two groups. Receiver operating characteristic (ROC) curve was used to find sensitivity and specificity of CT measurements in predicting COPD. Results: The sensitivity and specificity for MPA, RPA, LPA, AAo, DAo, MPA/AAo and MPA/DAo was 77.3% & 83%, 74.8% & 79.5%, 71.8 & 78.8, 56.7% & 42.6%, 30.1 & 60.3, 17.3% & 33.8%, 18.9% & 33.8% respectively. There was significant difference in diameters such as MPA, RPA, LPA, AAo and DAo among two groups (p value <0.001). Whereas no significant difference was found in MPA/AAo and MPA/ DAo ratios between two groups (p value >0.001). Conclusion: In present study, we found significant increase in MPA, RPA and LPA diameters in COPD patients compared to controls. Henceforth, our study concludes that MPA, RPA and LPA diameters could be useful as reliable indicators in predicting COPD.