International Journal of COPD (May 2021)
Chest Dynamic-Ventilatory Digital Radiography in Chronic Obstructive or Restrictive Lung Disease
Abstract
Noriyuki Ohkura,1 Rie Tanaka,2 Satoshi Watanabe,1 Johsuke Hara,1 Miki Abo,1 Yusuke Nakade,3 Junsei Horii,4 Yukihiro Matsuura,4 Dai Inoue,5 Munehisa Takata,6 Masaya Tamura,6 Isao Matsumoto,6 Shigeru Sanada,7 Kazuo Kasahara1 1Kanazawa University Hospital, Respiratory Medicine, Ishikawa, Japan; 2Kanazawa University, College of Medical, Pharmaceutical & Health Sciences, Ishikawa, Japan; 3Kanazawa University Hospital, Clinical Laboratory, Ishikawa, Japan; 4Kanazawa University Hospital, Department of Radiology, Ishikawa, Japan; 5Kanazawa University Hospital, Radiology, Ishikawa, Japan; 6Kanazawa University, Thoracic, Cardiovascular and General Surgery, Ishikawa, Japan; 7Komatsu University, Faculty of Health Sciences, Ishikawa, JapanCorrespondence: Noriyuki Ohkura Email [email protected]: The aim of this study was to identify the relationships between parameters obtained from dynamic-ventilatory digital radiography (DR) and ventilatory disorders.Methods: This study comprised 273 participants with respiratory diseases who underwent spirometry and functional residual capacity measurements (104 with normal findings on spirometry as controls, 139 with an obstructive lung disorder, 30 with a restrictive lung disorder) were assessed by dynamic-ventilatory DR. Sequential chest radiography images of the patient’s slow and maximum breathing were captured at 15 frames per second by a dynamic flat-panel imaging system. The system measured the following parameters: lung area at maximum inspiration divided by height (lung area_in/height), changes in tracheal diameter due to respiratory motions, rate of tracheal narrowing, diaphragmatic motion, and rate of change in lung area due to respiratory motion. Relationships between these parameters and ventilatory disorders were analyzed.Results: Lung area_in/height in patients with restrictive disorders showed significant decreases. Tracheal diameter change and tracheal narrowing rate in patients with obstructive disorders were significantly increased compared to both the control participants and patients with restrictive disorders. Patients with obstructive disorders and patients with restrictive disorders showed decreased diaphragmatic motion and lung area change rate. With the restrictive disorders as references, the area under the curve (AUC), sensitivity and specificity of lung area_in/height were 0.88, 0.77, and 0.88, respectively. With the obstructive disorders as references, the AUC, sensitivity and specificity of tracheal narrowing rate were 0.67, 0.53 and 0.81, respectively.Conclusion: Dynamic-ventilatory DR shows potential as a method for the detection and evaluation of ventilatory disorders in patients with respiratory diseases.Keywords: dynamic digital radiography, pulmonary function tests, spirometry, COPD, interstitial lung disease