Xenon-Enhanced Dual-Energy CT Imaging in Combined Pulmonary Fibrosis and Emphysema

• Published in: PloS one 2017-01, Vol.12 (1), p.e0170289-e0170289
• Main Authors: Sugino, Keishi, Kobayashi, Masahiro, Nakamura, Yasuhiko, Gocho, Kyoko, Ishida, Fumiaki, Isobe, Kazutoshi, Shiraga, Nobuyuki, Homma, Sakae
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Analysis; Asthma; Biology and Life Sciences; CAT scans; Chronic obstructive pulmonary disease; Comparative analysis; Computed tomography; Correlation; Diagnosis; Emphysema; Emphysema - diagnostic imaging; Emphysema - physiopathology; Energy; Feasibility studies; Female; Fibrosis; Health aspects; Humans; Lung diseases; Lungs; Male; Medical imaging; Medicine; Medicine and Health Sciences; Middle Aged; Obstructive lung disease; Patients; Physical Sciences; Pulmonary fibrosis; Pulmonary Fibrosis - diagnostic imaging; Pulmonary Fibrosis - physiopathology; Pulmonary functions; Quantitative analysis; Radiology; Research and Analysis Methods; Respiratory function; Test procedures; Thorax; Tomography; Tomography, X-Ray Computed - methods; Ventilation; Xenon
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0170289

Little has been reported on the feasibility of xenon-enhanced dual-energy computed tomography (Xe-DECT) in the visual and quantitative analysis of combined pulmonary fibrosis and emphysema (CPFE). We compared CPFE with idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD), as well as correlation with parameters of pulmonary function tests (PFTs). Studied in 3 groups were 25 patients with CPFE, 25 with IPF without emphysema (IPF alone), 30 with COPD. Xe-DECT of the patients' entire thorax was taken from apex to base after a patient's single deep inspiration of 35% stable nonradioactive xenon. The differences in several parameters of PFTs and percentage of areas enhanced by xenon between 3 groups were compared and analyzed retrospectively. The percentage of areas enhanced by xenon in both lungs were calculated as CPFE/IPF alone/COPD = 72.2 ± 15.1% / 82.2 ± 14.7% /45.2 ± 23.2%, respectively. In the entire patients, the percentage of areas enhanced by xenon showed significantly a positive correlation with FEV1/FVC (R = 0.558, P < 0.0001) and %FEV1, (R = 0.528, P < 0.0001) and a negative correlation with %RV (R = -0.594, P < 0.0001) and RV/TLC (R = -0.579, P < 0.0001). The percentage of areas enhanced by xenon in patients with CPFE showed significantly a negative correlation with RV/TLC (R = -0.529, P = 0.007). Xenon enhancement of CPFE indicated 3 different patterns such as upper predominant, diffuse, and multifocal defect. The percentage of areas enhanced by xenon in upper predominant defect pattern was significantly higher than that in diffuse defect and multifocal defect pattern among these 3 different patterns in CPFE. The percentage of areas enhanced by xenon demonstrated strong correlations with obstructive ventilation impairment. Therefore, we conclude that Xe-DECT may be useful for distinguishing emphysema lesion from fibrotic lesion in CPFE.