CT Scans Better Diagnostic for COPD

Computed tomography may be a better tool for diagnosing chronic obstructive pulmonary disease and the frequent comorbidity pulmonary hypertension than the conventional method of using pulmonary function tests, Chinese researchers report.

Computed tomography (CT) may be a better tool for diagnosing chronic obstructive pulmonary disease (COPD) and the frequent comorbidity pulmonary hypertension (PH) than the conventional method of using pulmonary function tests (PFTs). Xuesong Chen, of the Department of Respiratory Medicine at the First Affiliated Hospital of Nanjing Medical University in China, and colleagues completed a retrospective study, examining the use of CT for diagnosing COPD and PH. Their work was recently published in Dove Press.

The researchers “retrospectively reviewed 221 COPD patients and 115 other patients without cardiovascular or lung disease to analyzed the different indexes between groups and look for a more sensitive and specific index on CT measurement by which to provide a reliable basis for the diagnosis COPD and PH.” The 221 patients with COPD had a definitive diagnosis according to the Global Initiative for Chronic Obstructive Lung Disease Guidelines from 2013, which states that the diagnostic criteria is “FEV/forced vital capacity after inhaling bronchodilators in PFTs less than 70%.”

The majority of participants in both groups were male, and those in the COPD group were older than those in the non-COPD group. The researchers noted the diameters of the “main pulmonary artery (MPA), the right pulmonary artery (RPA) and left pulmonary artery branches, and ascending aorta (AAo) and descending aorta (DAo).” The also calculated the ratios of MPA/AAo and MPA/DAo. “There was a marked correlation between MPA/DAo and systolic pulmonary artery pressure” leading to the conclusion that “chest CT could be a simple and effective modality for diagnostic evaluation of COPD and its comorbidity, PH.”

As expected, the diameters of the MPA and branches were significantly larger in the COPD group than in the control group. In addition, “It was found that a composite index of MPA/AAo or MPA/DAo proved perfectly consistent in different studies and research subjects.” The researchers used logistic regression to learn that MPA diameter best predicted a diagnosis of COPD.

There were some limitations to this study. It was a retrospective design, and the researchers suggest that “prospective studies are needed for further verification.” The COPD group may have included some patients with acute exacerbation, and there was no way to be completely certain that some of the members of the control group didn’t have COPD.