Strain Analysis in Patients at High-Risk for COPD Using Four-Dimensional Dynamic-Ventilation CT

Abstract

Purpose To quantitatively identify abnormal lung motion in chronic obstructive pulmonary disease (COPD) using strain analysis, and further clarify the potential differences of deformation in COPD with different severity of airflow limitation. Materials and Methods Totally, 53 patients at high-risk for COPD were enrolled in this study. All CT examinations were performed on a 320-row MDCT scanner, and strain measurement based on dynamic-ventilation CT data was performed with a computational fluid dynamics analysis software (Micro Vec V3.6.2). The strain-related parameters derived from the whole expiration phase ( PS max-all , PS mean-all , Speed max-all ), the first 2s of expiration phase ( PS max2s , PS mean2s , Speed max2s ) were divided respectively by the changes in lung volume to adjust for the degree of expiration. Spearman rank correlation analysis was used to evaluate associations between the strain-related parameters and various spirometric parameters. Comparisons of the strain-related parameters between COPD and non-COPD patients, between GOLD I (mild airflow restriction) and GOLD II–IV (moderate to severe airflow restriction) were made using the Mann–Whitney U -test. Receiver-operating characteristic (ROC) analysis was performed to evaluate the diagnostic performance of the strain-related parameters for COPD. P <0.05 was considered statistically significant. Results Strain-related parameters demonstrated positive correlations with spirometric parameters ( ρ =0.275~0.687, P <0.05), suggesting that heterogeneity in lung motion was related to abnormal spirometric results. Strain-related parameters can quantitatively distinguish COPD from non-COPD patients with moderate diagnostic significance with the AUC values ranged from 0.821 to 0.894. Furthermore, parameters of the whole expiration phase ( PS max-all , Speed max-al l ) demonstrated significant differences ( P =0.005; P =0.04) between COPD patients with mild and moderate to severe airflow limitation. Conclusion Strain-related parameters derived from dynamic-ventilation CT data covering the whole lung associated with lung function changes in COPD, reflecting the severity of airflow limitation in some degree, even though its utility in severe COPD patients remains to be investigated.

Early Diagnosis of High-Risk Chronic Obstructive Pulmonary Disease Based on Quantitative High-Resolution Computed Tomography Measurements

“…The latest research shows that the incidence rate of COPD in China has been increasing, with nearly 99 million patients over 40 years old, accounting for 13.7% of the population over 40 years old in International Journal of Chronic Obstructive Pulmonary Disease 2023:18 3099-3114 a long time to manifest clinically. 35 Some studies have investigated the participants with high-risk COPD who aged over 18 years old and have clinical respiratory symptoms and explored the potential differences of deformation in COPD with different severity of airflow limitation based on the quantitative CT of lung motion; 36 only the QCT of emphysema were considered here and the inclusion criteria were worth pursuing. According to the global initiative for COPD, the decrease in FEV1 is considered to be a predictor of COPD development, which can serve to determine the severity of airflow obstruction.…”