New Method for Combined Quantitative Assessment of Air-Trapping and Emphysema on Chest Computed Tomography in Chronic Obstructive Pulmonary Disease: Comparison with Parametric Response Mapping

• Published in: Korean journal of radiology Vol. 22; no. 10; pp. 1719 - 1729
• Main Authors: Hwang, Hye Jeon, Seo, Joon Beom, Lee, Sang Min, Kim, Namkug, Yi, Jaeyoun, Lee, Jae Seung, Lee, Sei Won, Oh, Yeon-Mok, Lee, Sang-Do
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Society of Radiology 01-10-2021; 대한영상의학회
• Subjects: Airway management; Body mass index; Chronic obstructive pulmonary disease; Dyspnea; Emphysema; Lung diseases; Lungs; Medical imaging; Patients; Questionnaires; Registration; Thoracic Imaging; Tomography; 방사선과학
• ISSN: 1229-6929; 2005-8330
• DOI: 10.3348/kjr.2021.0033

Objective Emphysema and small-airway disease are the two major components of chronic obstructive pulmonary disease (COPD). We propose a novel method of quantitative computed tomography (CT) emphysema air-trapping composite (EAtC) mapping to assess each COPD component. We analyzed the potential use of this method for assessing lung function in patients with COPD. Materials and Methods A total of 584 patients with COPD underwent inspiration and expiration CTs. Using pairwise analysis of inspiration and expiration CTs with non-rigid registration, EAtC mapping classified lung parenchyma into three areas: Normal, functional air trapping (fAT), and emphysema (Emph). We defined fAT as the area with a density change of less than 60 Hounsfield units (HU) between inspiration and expiration CTs among areas with a density less than −856 HU on inspiration CT. The volume fraction of each area was compared with clinical parameters and pulmonary function tests (PFTs). The results were compared with those of parametric response mapping (PRM) analysis. Results The relative volumes of the EAtC classes differed according to the Global Initiative for Chronic Obstructive Lung Disease stages (pr = −0.659–0.674, pppp Conclusion The proposed quantitative CT EAtC mapping provides comprehensive lung functional information on each disease component of COPD, which may serve as an imaging biomarker of lung function.