Projected lung area using dynamic X-ray (DXR) with a flat-panel detector system and automated tracking in patients with chronic obstructive pulmonary disease (COPD). Issue 157 (December 2022)

• Record Type: Journal Article
• Authors: Hino, Takuya; Tsunomori, Akinori; Fukumoto, Takenori; Hata, Akinori; Hida, Tomoyuki; Yamada, Yoshitake; Ueyama, Masako; Kamitani, Takeshi; Nishino, Mizuki; Kurosaki, Atsuko; Jinzaki, Masahiro; Ishigami, Kousei; Honda, Hiroshi; Yoneyama, Tsutomu; Nagatsuka, Sumiya; Kudoh, Shoji; Hatabu, Hiroto
• Is Part Of: European journal of radiology. Issue 157(2022)
• Publication Date: 2022-12
• Subjects: Dynamic X-ray -- Chest radiograph -- Pulmonary function -- COPD -- Projected lung area; COPD chronic obstructive pulmonary disease -- DXR dynamic X-ray -- ΔPLA the difference of PLA between end-inspiration and end-expiration in tidal or forced breathing -- FEV1 forced expiratory volume percent in one second -- FEV1%VC forced expiratory volume percent in one second divided by forced vital capacity -- GOLD global initiative for chronic obstructive lung disease -- %FEV1 percent predicted forced expiratory volume in one second -- %VC percent predicted vital capacity -- PLA projected lung area -- PFT pulmonary function test -- rs Spearman's rank correlation coefficient -- TV tidal volume -- VC vital capacity; Medical radiology -- Periodicals; Radiology -- Periodicals; Radiologie médicale -- Périodiques; Medical radiology; Periodicals; 616.075705
• DOI: 10.1016/j.ejrad.2022.110546
• Languages: English
• ISSNs: 0720-048X

Abstract

Highlights: COPD severe group has larger projected lung area (PLA) in inspiratory and expiratory phases with tidal and forced respiration in both lungs compared to normal group. PLA had mild to moderate correlation with %FEV1, while ΔPLA correlated with VC in forced breathing. Automatically tracked PLA showed strong correlation with manually contoured PLA (r = 0.96, p < 0.001). Abstract: Objectives: To assess the association of projected lung area (PLA) measured by DXR with demographic data, pulmonary function, and COPD severity, and to generate PLA over time curves using automated tracking. Methods: This retrospective study recruited healthy volunteers and COPD patients. Participants were classified into three groups: normal, COPD mild and COPD severe. PLA was calculated from the manually traced bilateral lung contours. PLA over time curves were produced using automated tracking, which was used to calculate slope and intercept by approximate line during forced expiration. The correlation of PLA, difference of PLA between end-inspiration and end-expiration (ΔPLA), slope, and intercept with demographic data and pulmonary function tests were investigated. The difference of PLA, ΔPLA, intercept, and slope among three groups were also evaluated. Results: This study enrolled 45 healthy volunteers and 32 COPD patients. COPD severe group had larger PLA in both lungs at tidal/forced end-inspiration/expiration, smaller slope, and larger intercept than normal group (p < 0.001). PLA was correlated with % forced expiratory volume in one second (%FEV1 ) (rs from −0.42 to −0.31, p ≤ 0.01). ΔPLA in forced breathing showed moderate correlation with vital capacity (VC) (rs = 0.58, p < 0.001), while ΔPLA in tidal breathing showed moderate correlation with %FEV1 (rs = -0.52, p < 0.001) as well as mild correlation with tidal volume (rs = 0.24, p = 0.032). Intercept was slightly underestimated compared with manually contoured PLA (p < 0.001). Conclusion: COPD patients had larger PLA than healthy volunteers. PLA and ΔPLA in tidal breathing showed mild to moderate correlation with %FEV1 .