Assessment Of Changes In Regional Xenon-Ventilation, Perfusion, And Ventilation-Perfusion Mismatch Using Dual-Energy Computed Tomography After Pharmacological Treatment In Patients With Chronic Obstructive Pulmonary Disease: Visual And Quantitative Analysis

Abstract

Hye Jeon Hwang,1 Sang Min Lee,1 Joon Beom Seo,1 Jae Seung Lee,2 Namkug Kim,1 Cherry Kim,3 Sang Young Oh,1 Sei Won Lee2 1Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Songpa-Gu, Seoul 138-736, South Korea; 2Department of Pulmonary and Critical Care Medicine, Clinical Research Center for Chronic Obstructive Airway Diseases, Asan Medical Center, University of Ulsan College of Medicine, Songpa-Gu, Seoul 138-736, South Korea; 3Department of Radiology, Ansan Hospital, Korea University College of Medicine, Danwon-gu, Ansan-si, Gyeonggi-do, KoreaCorrespondence: Sang Min LeeDepartment of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 86 Asanbyeongwon-Gil, Songpa-Gu, Seoul 138-736, South KoreaTel [phone]Fax [phone]Email [email protected]: To assess changes in regional ventilation (V), perfusion (Q), and V-Q mismatch in patients with chronic obstructive pulmonary disease (COPD) after pharmacologic treatment using combined xenon-enhanced V and iodine-enhanced Q dual-energy CT (DECT).Patients and methods: Combined V and Q DECT were performed at baseline and after three-month pharmacologic treatment in 52 COPD patients. Anatomically co-registered virtual non-contrast images, V, Q, and V/Qratio maps were obtained. V/Q pattern was visually determined to be matched, mismatched, or reversed-mismatched and compared with the regional parenchymal disease patterns of each segment. DECT parameters for V, Q, and V-Q imbalance were quantified.Results: The parenchymal patterns on CT were not changed at follow-up. The segments with matched V/Q pattern were increased (80.2% to 83.6%) as the segments with reversed-mismatched V/Q pattern were decreased with improving ventilation (17.6% to 13.8%) after treatment. Changes of V/Q patterns were mostly observed in segments with bronchial wall thickening. Compared with patients without bronchial wall thickening, the quantified DECT parameters of V-Q imbalance were significantly improved in patients with bronchial wall thickening (p < 0.05). Changes in forced expiratory volume in one second after treatment were correlated with changes in the quantified DECT parameters (r = 0.327–0.342 or r = −0.406 and −0.303; p < 0.05).Conclusion: DECT analysis showed that the V-Q imbalance was improved after the pharmacological treatment in COPD patients, although the parenchymal disease patterns remained unchanged. This improvement of V-Q imbalance may occur mostly in the areas with bronchial wall thickening.Keywords: chronic obstructive pulmonary disease, dual-energy computed tomography, ventilation-perfusion mismatch, pharmacotherapy  

Keywords

• Chronic obstructive pulmonary disease
• dual-energy computed tomography
• Ventilation-Perfusion mismatch
• Pharmacotherapy