In:
Respiration, S. Karger AG, Vol. 94, No. 4 ( 2017), p. 336-345
Abstract:
〈 b 〉 〈 i 〉 Background: 〈 /i 〉 〈 /b 〉 Disease accumulates in the small airways without being detected by conventional measurements. 〈 b 〉 〈 i 〉 Objectives: 〈 /i 〉 〈 /b 〉 To quantify small airway disease using a novel computed tomography (CT) inspiratory-to-expiratory approach called the disease probability measure (DPM) and to investigate the association with pulmonary function measurements. 〈 b 〉 〈 i 〉 Methods: 〈 /i 〉 〈 /b 〉 Participants from the population-based CanCOLD study were evaluated using full-inspiration/full-expiration CT and pulmonary function measurements. Full-inspiration and full-expiration CT images were registered, and each voxel was classified as emphysema, gas trapping (GasTrap) related to functional small airway disease, or normal using two classification approaches: parametric response map (PRM) and DPM (VIDA Diagnostics, Inc., Coralville, IA, USA). 〈 b 〉 〈 i 〉 Results: 〈 /i 〉 〈 /b 〉 The participants included never-smokers ( 〈 i 〉 n 〈 /i 〉 = 135), at risk ( 〈 i 〉 n 〈 /i 〉 = 97), Global Initiative for Chronic Obstructive Lung Disease I (GOLD I) ( 〈 i 〉 n 〈 /i 〉 = 140), and GOLD II chronic obstructive pulmonary disease ( 〈 i 〉 n 〈 /i 〉 = 96). PRM 〈 sub 〉 GasTrap 〈 /sub 〉 and DPM 〈 sub 〉 GasTrap 〈 /sub 〉 measurements were significantly elevated in GOLD II compared to never-smokers ( 〈 i 〉 p 〈 /i 〉 〈 0.01) and at risk ( 〈 i 〉 p 〈 /i 〉 〈 0.01), and for GOLD I compared to at risk ( 〈 i 〉 p 〈 /i 〉 〈 0.05). Gas trapping measurements were significantly elevated in GOLD II compared to GOLD I ( 〈 i 〉 p 〈 /i 〉 〈 0.0001) using the DPM classification only. Overall, DPM classified significantly more voxels as gas trapping than PRM ( 〈 i 〉 p 〈 /i 〉 〈 0.0001); a spatial comparison revealed that the expiratory CT Hounsfield units (HU) for voxels classified as DPM 〈 sub 〉 GasTrap 〈 /sub 〉 but PRM 〈 sub 〉 Normal 〈 /sub 〉 (PRM 〈 sub 〉 Normal 〈 /sub 〉 - DPM 〈 sub 〉 GasTrap 〈 /sub 〉 = -785 ± 72 HU) were significantly reduced compared to voxels classified normal by both approaches (PRM 〈 sub 〉 Normal 〈 /sub 〉 -DPM 〈 sub 〉 Normal 〈 /sub 〉 = -722 ± 89 HU; 〈 i 〉 p 〈 /i 〉 〈 0.0001). DPM and PRM 〈 sub 〉 GasTrap 〈 /sub 〉 measurements showed similar, significantly associations with forced expiratory volume in 1 s (FEV 〈 sub 〉 1 〈 /sub 〉 ) ( 〈 i 〉 p 〈 /i 〉 〈 0.01), FEV 〈 sub 〉 1 〈 /sub 〉 /forced vital capacity ( 〈 i 〉 p 〈 /i 〉 〈 0.0001), residual volume/total lung capacity ( 〈 i 〉 p 〈 /i 〉 〈 0.0001), bronchodilator response ( 〈 i 〉 p 〈 /i 〉 〈 0.0001), and dyspnea ( 〈 i 〉 p 〈 /i 〉 〈 0.05). 〈 b 〉 〈 i 〉 Conclusion: 〈 /i 〉 〈 /b 〉 CT inspiratory-to-expiratory gas trapping measurements are significantly associated with pulmonary function and symptoms. There are quantitative and spatial differences between PRM and DPM classification that need pathological investigation.
Type of Medium:
Online Resource
ISSN:
0025-7931
,
1423-0356
Language:
English
Publisher:
S. Karger AG
Publication Date:
2017
detail.hit.zdb_id:
1464419-8
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