European Radiology

, Volume 27, Issue 7, pp 2818–2827 | Cite as

Assessment of regional emphysema, air-trapping and Xenon-ventilation using dual-energy computed tomography in chronic obstructive pulmonary disease patients

  • Sang Min Lee
  • Joon Beom Seo
  • Hye Jeon Hwang
  • Namkug Kim
  • Sang Young Oh
  • Jae Seung Lee
  • Sei Won Lee
  • Yeon-Mok Oh
  • Tae Hoon Kim



To compare the parenchymal attenuation change between inspiration/expiration CTs with dynamic ventilation change between xenon wash-in (WI) inspiration and wash-out (WO) expiration CTs.


52 prospectively enrolled COPD patients underwent xenon ventilation dual-energy CT during WI and WO periods and pulmonary function tests (PFTs). The parenchymal attenuation parameters (emphysema index (EI), gas-trapping index (GTI) and air-trapping index (ATI)) and xenon ventilation parameters (xenon in WI (Xe-WI), xenon in WO (Xe-WO) and xenon dynamic (Xe-Dyna)) of whole lung and three divided areas (emphysema, hyperinflation and normal) were calculated on virtual non-contrast images and ventilation images. Pearson correlation, linear regression analysis and one-way ANOVA were performed.


EI, GTI and ATI showed a significant correlation with Xe-WI, Xe-WO and Xe-Dyna (EI R = −.744, −.562, −.737; GTI R = −.621, −.442, −.629; ATI R = −.600, −.421, −.610, respectively, p < 0.01). All CT parameters showed significant correlation with PFTs except forced vital capacity (FVC). There was a significant difference in GTI, ATI and Xe-Dyna in each lung area (p < 0.01).


The parenchymal attenuation change between inspiration/expiration CTs and xenon dynamic change between xenon WI- and WO-CTs correlate significantly. There are alterations in the dynamics of xenon ventilation between areas of emphysema.

Key Points

The xenon ventilation change correlates with the parenchymal attenuation change.

The xenon ventilation change shows the difference between three lung areas.

The combination of attenuation and xenon can predict more accurate PFTs.


Chronic obstructive pulmonary disease Air trapping Xenon Ventilation Dual-energy CT 



6-minute walking distance test


Air-trapping index


Chronic obstructive pulmonary disease


Diffusing capacity of lung for carbon monoxide


Emphysema index


Mean forced expiratory flow between 25% and 75% of FVC


Forced expiratory volume in 1 second


Forced vital capacity


Global Initiative for Chronic Obstructive Lung Disease


Gas-trapping index


Korean Obstructive Lung Disease


Mean lung density


Pulmonary function tests


Residual volume


Total lung capacity







The scientific guarantor of this publication is Dr. Joon Beom Seo. The authors of this manuscript declare no relationships with any companies whose products or services may be related to the subject matter of the article. This study received funding from the Korean Health Technology R&D Project, Ministry of Health & Welfare, Republic of Korea (no. A111599). The authors thank Jung Bok Lee, PhD, for statistical assistance, and Yongjun Chang, PhD, Taekjin Jang, BS, Soo Jin Park, BS, Junghye Kang, BS and Heejun Park, BS, for their technical assistance. Institutional Review Board approval was obtained. Written informed consent was obtained from all subjects (patients) in this study. Some study subjects or cohorts have been previously reported in Hwang et al. (2015) Invest Radiol. 51:306-15

The paper is a prospective, diagnostic or prognostic study, and was performed at one institution.


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Copyright information

© European Society of Radiology 2016

Authors and Affiliations

  • Sang Min Lee
    • 1
    • 2
  • Joon Beom Seo
    • 1
  • Hye Jeon Hwang
    • 1
    • 3
  • Namkug Kim
    • 1
  • Sang Young Oh
    • 1
  • Jae Seung Lee
    • 4
  • Sei Won Lee
    • 4
  • Yeon-Mok Oh
    • 4
  • Tae Hoon Kim
    • 2
  1. 1.Division of Cardiothoracic Radiology, Department of Radiology and Research Institute of Radiology, Asan Medical CenterUniversity of Ulsan College of MedicineSeoulRepublic of Korea
  2. 2.Department of Radiology, Research Istitute of Radiological ScienceYonsei University College of Medicine, Gangnam Severance HospitalSeoulRepublic of Korea
  3. 3.Department of Radiology, Hallym University College of MedicineHallym University Sacred Heart HospitalAnyang-siRepublic of Korea
  4. 4.Department of Pulmonary and Critical Care Medicine, and Clinical Research Center for Chronic Obstructive Airway Diseases, Asan Medical CenterUniversity of Ulsan College of MedicineSeoulRepublic of Korea

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