Pulmonary Dual Hemodynamic Changes in Severe COPD Patients: A Quantitative Study Using Low-Dose CT Lung Perfusion Scan

Background: Computed tomography (CT) lung perfusion scan could be used to evaluate regional, morphologic, and functional changes in chronic obstructive pulmonary disease (COPD) noninvasively. However, the dual hemodynamic changes in severe COPD patients have not been studied quantitatively using CT lung perfusion scan. Objectives: To determine the dual hemodynamic changes quantitatively in patients with severe COPD by using low-dose CT lung perfusion scan. Patients and Methods: Fifteen patients with severe COPD (global initiative for chronic obstructive lung disease [GOLD] class IV) and 31 controls were enrolled. All participants received low-dose CT lung perfusion scan using a Toshiba 320-detector row dynamic volumetric CT. The perfusion parameters including pulmonary artery flow (PAF), bronchial artery flow (BAF), perfusion index [PI = PAF/(PAF + BAF)] and time to peak (TTP) of the time density curve were generated and compared between the impaired lung parenchyma in the COPD group and normal lung parenchyma in the control group. Results: The PAF and PI values in theCOPD group were significantly lower than that in the control group (P< 0.001, P < 0.001), while the BAF value was significantly higher (P < 0.001). The TTP of impaired lung parenchyma was significantly prolonged compared to the normal lung parenchyma (P < 0.001). Conclusion: Patients with severe COPD have distinct changes in pulmonary dual hemodynamics. Low-dose lung perfusion scan using a 320-detector row dynamic volumetric CT could be used to evaluate the pulmonary dual hemodynamics.