Quantitative computed tomography analysis of emphysema severity and distribution in chronic obstructive lung disease, correlation with clinical findings

Abstract

Quantitative computed tomography analysis of emphysema severity and distribution in chronic obstructive lung disease, correlation with clinical findings Introduction: This study aimed to evaluate the correlation between different densitometric parameters on chest computed tomography (CT) and pulmonary function tests (PFT) of patients with emphysema-predominant chronic obstructive pulmonary disease (COPD). Materials and Methods: A retrospective evaluation was made of 56 patients with COPD. The lungs were segmented into nine sections. Normal and emph-ysematous parenchyma were measured using low attenuation area percentage (%LAA), percentile density (PD), and mean lung density (MLD) parameters. The effects of emphysema distribution on PFT were evaluated using %LAA, PD, MLD, kurtosis and skewness methods. Results: Fifty-six patients, all diagnosed with COPD, were evaluated. The %LAA-910 method showed significant correlation with forced expiratory volume in one second (FEV1) compared to other densitometric parameters (p= <0.001, r=-0.556). Other densitometric parameters differed between segments in terms of sensitivity for FEV1. It was determined that right lung mid-zone segment involvement affected FEV1 more than other segments when the %LAA-910 method was used (p= <0.001, r=-0.569). %LAA-950 had the largest area under the curve in ROC curve analysis and was determined to have 2.2% diagnostic property for predicting Global Initiative for Obstructive Lung Disease (GOLD) AB-CD staging (sensitivity 81%, specificity 74%). Conclusion: Quantitative analysis is an objective method for determining the distribution and severity of emphysema. There was a significant correlation between densitometry and PFT values. Quantitative analysis may be considered suitable for use in evaluating the severity of emphysema and predicting the clinical findings of patients.