Pulmonary Imaging Biomarkers of Gas Trapping and Emphysema in COPD:<sup>3</sup>He MR Imaging and CT Parametric Response Maps

Capaldi, Dante P. I.; Zha, Nanxi; Guo, Fumin; Pike, Damien; McCormack, David G.; Kirby, Miranda; Párraga, Grace

doi:10.1148/radiol.2015151484

Cited by 58 publications

(61 citation statements)

References 45 publications

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“…16 Recently, 19 F-MRI has been shown to correlate with pulmonary function testing in COPD patients. 10,20,27 In the present study we also showed significant correlations of FD-FV with clinical lung function test parameters such as FEV1. Accordingly, FD-FV values decreased with increasing GOLD stage.…”

Section: Discussionsupporting

confidence: 79%

Comparison of quantitative regional ventilation‐weighted fourier decomposition MRI with dynamic fluorinated gas washout MRI and lung function testing in COPD patients

Kaireit

Gutberlet

Voskrebenzev

et al. 2017

Magnetic Resonance Imaging

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Section: Discussionsupporting

confidence: 79%

Comparison of quantitative regional ventilation‐weighted fourier decomposition MRI with dynamic fluorinated gas washout MRI and lung function testing in COPD patients

Kaireit

Gutberlet

Voskrebenzev

et al. 2017

Magnetic Resonance Imaging

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“…Another study compared ventilation and perfusion defects measured on MRI with PRM measurements of emphysema and small airways disease on CT. Ventilation defects were associated with emphysema and small airways disease and diffusion measurements were significantly raised in areas of gas trapping [127]. MR technology is still in early development but does provide an advantage over CT by allowing functional imaging and importantly being radiation free.…”

Section: Other Imaging Modalitiesmentioning

confidence: 99%

Present and future utility of computed tomography scanning in the assessment and management of COPD

Ostridge

Wilkinson

2016

Eur Respir J

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likely to have important implications for understanding disease progression and the future management of this condition [2]. There are currently no significant diseasemodifying medications for COPD and there have not been the improvements in outcome seen in other chronic diseases. Other tools are required in addition to spirometry to help explain the heterogeneity and provide further insights into approaches to study and treat COPD. CT has current practical applications in the routine management and investigation of the disease and with the development of novel analysis techniques has the potential to provide further details about the pulmonary and extra-pulmonary manifestations of COPD. Computed Tomography in Current Clinical PractisePrior to the 1970s histological and post mortem studies were required to study structural changes of the lung. The introduction of CT made it possible to visualise the thorax and assess lung structure non-invasively. In COPD CT can identify key morphological features, including emphysema, bronchial wall thickening and gas trapping. These pathologies contribute directly to airflow obstruction and therefore CT has the potential to provide vital insights into the underlying pathophysiological changes of COPD. Despite this, routine CT imaging has not necessarily been widely adopted in clinical practise and its place in the management and investigation of COPD has not been firmly established. The GOLD guidelines do not routinely recommend CT scanning in COPD and only advise that it may be helpful in differential diagnosis or when surgical options are being considered [3]. This general ambivalence is highlighted by a study of attitudes in respiratory physicians and surgeons in the UK where only 32% thought it necessary for patients with severe COPD to have a CT scan [4].There are a number of reasons why the use of CT has not become routine in COPD. One of the most important is the perceived notion that using CT does not alter management, although this is not strictly true. The National Emphysema Treatment Trial (NETT) demonstrated that patients with advanced upper lobe emphysema and limited exercise ability improved after lung volume reduction surgery [5]. There has also been considerable progress and experience in using endobronchial treatments for severe emphysema including coils, valves, sealant and airway bypass. In the correct patients with severe heterogeneous emphysema these treatments can lead to significant improvement in pulmonary physiology and functional capacity [6, 7]. CT imaging can also identify bullous disease, which may be amenable to surgery and bullectomy can lead to improved health status [8]. It therefore seems clear that patients with severe COPD require CT imaging to determine which patients are appropriate for these techniques.CT imaging can also detect concomitant pulmonary pathology in COPD. Bronchiectasis is particularly prevalent, with studies demonstrating 50% of COPD patients having CT evidence of the disease [9][10][11]. When present bronchiectasis is asso...

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“…By registering CT images acquired at full inspiration to images acquired at full expiration and applying established Hounsfield unit (HU) thresholds, regions of the lung that trap gas that are not related to emphysema, and hence may be attributed to small airway disease, can be quantified. Although measurements of gas trapping related to "functional" small airway disease generated using this technique have been shown to be reproducible over short periods of time [9] , to be correlated with pulmonary function [8] , to show spatial agreement with other imaging modalities [10] , and to be associated with longitudinal changes in forced expiratory volume in 1 s (FEV 1 ) [11] , these measurements have yet to be pathologically validated. Furthermore, measurements generated using a single HU threshold have obvious limitations, and therefore there is motivation to investigate other CT inspiratory-to-expiratory classification approaches.…”

Section: Introductionmentioning

confidence: 99%

A Novel Method of Estimating Small Airway Disease Using Inspiratory-to-Expiratory Computed Tomography

Kirby

Yin²,

Tschirren³

et al. 2017

Respiration

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Background: Disease accumulates in the small airways without being detected by conventional measurements. Objectives: 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. Methods: 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). Results: The participants included never-smokers (n = 135), at risk (n = 97), Global Initiative for Chronic Obstructive Lung Disease I (GOLD I) (n = 140), and GOLD II chronic obstructive pulmonary disease (n = 96). PRM_GasTrap and DPM_GasTrap measurements were significantly elevated in GOLD II compared to never-smokers (p < 0.01) and at risk (p < 0.01), and for GOLD I compared to at risk (p < 0.05). Gas trapping measurements were significantly elevated in GOLD II compared to GOLD I (p < 0.0001) using the DPM classification only. Overall, DPM classified significantly more voxels as gas trapping than PRM (p < 0.0001); a spatial comparison revealed that the expiratory CT Hounsfield units (HU) for voxels classified as DPM_GasTrap but PRM_Normal (PRM_Normal- DPM_GasTrap = -785 ± 72 HU) were significantly reduced compared to voxels classified normal by both approaches (PRM_Normal-DPM_Normal = -722 ± 89 HU; p < 0.0001). DPM and PRM_GasTrap measurements showed similar, significantly associations with forced expiratory volume in 1 s (FEV₁) (p < 0.01), FEV₁/forced vital capacity (p < 0.0001), residual volume/total lung capacity (p < 0.0001), bronchodilator response (p < 0.0001), and dyspnea (p < 0.05). Conclusion: 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.

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Pulmonary Imaging Biomarkers of Gas Trapping and Emphysema in COPD:³He MR Imaging and CT Parametric Response Maps

Cited by 58 publications

References 45 publications

Comparison of quantitative regional ventilation‐weighted fourier decomposition MRI with dynamic fluorinated gas washout MRI and lung function testing in COPD patients

Comparison of quantitative regional ventilation‐weighted fourier decomposition MRI with dynamic fluorinated gas washout MRI and lung function testing in COPD patients

Present and future utility of computed tomography scanning in the assessment and management of COPD

A Novel Method of Estimating Small Airway Disease Using Inspiratory-to-Expiratory Computed Tomography

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Pulmonary Imaging Biomarkers of Gas Trapping and Emphysema in COPD:3He MR Imaging and CT Parametric Response Maps

Cited by 58 publications

References 45 publications

Comparison of quantitative regional ventilation‐weighted fourier decomposition MRI with dynamic fluorinated gas washout MRI and lung function testing in COPD patients

Comparison of quantitative regional ventilation‐weighted fourier decomposition MRI with dynamic fluorinated gas washout MRI and lung function testing in COPD patients

Present and future utility of computed tomography scanning in the assessment and management of COPD

A Novel Method of Estimating Small Airway Disease Using Inspiratory-to-Expiratory Computed Tomography

Contact Info

Product

Resources

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Pulmonary Imaging Biomarkers of Gas Trapping and Emphysema in COPD:³He MR Imaging and CT Parametric Response Maps