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The article reports on the spirometric response of inhalation administration of bronchodilators and associated dysanapsis. Topics include use of computed tomography for the assessment of dysanapsis, data regarding airway-to-lung ratio of participants and spirometric response data after administration of short-acting bronchodilator's standard dose.

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). PRMGasTrap and DPMGasTrap 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 DPMGasTrap but PRMNormal (PRMNormal- DPMGasTrap = -785 ± 72 HU) were significantly reduced compared to voxels classified normal by both approaches (PRMNormal-DPMNormal = --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. [ABSTRACT FROM AUTHOR]

Purpose Recent pulmonary imaging research has revealed that in patients with chronic obstructive pulmonary disease ( COPD) and asthma, structural and functional abnormalities are spatially heterogeneous. This novel information may help optimize treatment in individual patients, monitor interventional efficacy, and develop new treatments. Moreover, by automating the measurement of regional biomarkers for the 19 different anatomical lung segments, there is an opportunity to embed imaging biomarkers into clinically acceptable clinical workflows and improve lung disease clinical care. Therefore, to exploit the regional structure-function information provided by thoracic imaging, and as a first step toward this goal, our objective was to develop a fully automated registration pipeline for thoracic x-ray computed tomography ( CT) and inhaled gas functional magnetic resonance imaging ( MRI) whole lung and segmental structure-function biomarkers. Methods Thirty-five patients including 15 severe, poorly controlled asthmatics and 20 COPD patients [classified according to the global initiative for chronic obstructive lung disease ( GOLD) criteria)] provided written informed consent to a study protocol approved by Health Canada and underwent pulmonary function tests, MRI, and CT during a single 2-hour visit. Using this diverse patient dataset, we developed and evaluated a joint deformable registration approach to simultaneously coregister CT with both 1H and 3He MRI by enforcing the similarity of the deformation fields from the two individual registrations. We derived a simpler model that was equivalent to the original challenging optimization problem through variational analysis and the simpler model gave rise to an efficient numerical solver that was parallelized on a graphics processing unit. The coregistered CT-3He MRI and whole lung/segmental lung masks were used to generate whole lung and segmental 3He MRI ventilation defect percent ( VDP). To estimate fiducial localization reproducibility, a single observer manually identified 109 pairs of CT and 3He MRI fiducials for 35 patient images on five separate occasions and determined the fiducial localization error ( FLE). CT-3He MRI registration accuracy was evaluated using the target registration error ( TRE). Whole lung VDP generated using the algorithm was compared with VDP generated using a previously validated semiautomated approach and computational efficiency was evaluated using run time. Results In 35 patients including 15 with severe asthma and 20 with COPD, mean forced expiratory volume in 1 s ( FEV1) was 63±24%pred and FEV1/forced vital capacity ( FVC) was 54 ± 17%. FLE was 0.16 mm and 0.34 mm for 3He MRI and CT, respectively. TRE was 4.5 ± 2.0 mm, 4.0 ± 1.7 mm, 4.8 ± 2.3 mm for asthma, COPD GOLD II, and GOLD III groups, respectively, with a mean of 4.4 ± 2.0 mm for the entire dataset. TRE was significantly improved for joint CT-1H/3He MRI registration compared with CT-1H MRI rigid registration ( P < 0.0001). Whole lung VDP generated using the pipeline was not significantly different ( P = 0.37) compared to a semiautomated method with which it was strongly correlated (r = 0.93, P < 0.0001). The fully automated pipeline required 11 ± 0.4 min to generate whole lung and segmental VDP. Conclusions For a diverse group of patients with COPD and asthma, whole lung and segmental VDP was measured using an automated lung image analysis pipeline which provides a way to incorporate lung functional biomarkers into clinical research and patient care. [ABSTRACT FROM AUTHOR]

While the recent development of quantitative imaging methods have led to their increased use in the diagnosis and management of many chronic diseases, medical imaging still plays a limited role in the management of chronic obstructive pulmonary disease (COPD). In this review we highlight three pulmonary imaging modalities: computed tomography (CT), magnetic resonance imaging (MRI) and optical coherence tomography (OCT) imaging and the COPD biomarkers that may be helpful for managing COPD patients. We discussed the current role imaging plays in COPD management as well as the potential role quantitative imaging will play by identifying imaging phenotypes to enable more effective COPD management and improved outcomes. [ABSTRACT FROM AUTHOR]

: COPD biomarkers are urgently required for clinical trials of new therapies. We evaluated the longitudinal change and relationship of MRI and CT biomarkers of COPD with St. George's Respiratory Questionnaire (SGRO) and FEV1 worsening over 30 months. Among imaging biomarkers, only the longitudinal change in MRI ventilation defect percent (VDP) was greater in ever-smoker (n=34/p<0.05) and COPD (n=48/p<0.0001) subgroups compared with never-smokers (n=42). Only the longitudinal change in VDP was correlated with change in SGRQ (r=0.26/p=0.03), and only baseline VDP predicted longitudinal change in SGRQ>minimum clinically important difference (p=0.047) in mild-to-moderate COPD. These data strongly support the use of MRI intermediate endpoints in COPD studies.Trial Registration Number: NCT02723474; Status: Recruiting. [ABSTRACT FROM AUTHOR]

Background: The functional effects of abnormal diffusing capacity for carbon monoxide (DLCO) in ex-smokers without chronic obstructive pulmonary disease (COPD) are not well understood. Objective: We aimed to evaluate and compare well established clinical, physiological and emerging imaging measurements in ex-smokers with normal spirometry and abnormal DLCO with a group of ex-smokers with normal spirometry and DLCO and ex-smokers with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage I COPD. Methods We enrolled 38 ex-smokers and 15 subjects with stage I COPD who underwent spirometry, plethysmography, St George's Respiratory Questionnaire (SGRQ), 6 min Walk Test (6MWT), x-ray CT and hyperpolarised helium-3 (³He) MRI. The 6MWT distance (6MWD), SGRQ scores, ³He MRI apparent diffusion coefficients (ADC) and CT attenuation values below -950 HU (RA950) were evaluated. Results: Of 38 ex-smokers without COPD, 19 subjects had abnormal DLCO with significantly worse ADC ( p=0.01), 6MWD ( p=0.008) and SGRQ (p=0.01) but not RA950 ( p=0.53) compared with 19 ex-smokers with normal DLCO. Stage I COPD subjects showed significantly worse ADC (p=0.02), RA950 (p=0.0008) and 6MWD (p=0.005), but not SGRQ (p=0.59) compared with subjects with abnormal DLCO. There was a significant correlation for ³He ADC with SGRQ (r=0.34, p=0.02) and 6MWD (r=-0.51, p=0.0002). Conclusions: In ex-smokers with normal spirometry and CT but abnormal DLCO, there were significantly worse symptoms, 6MWD and ³He ADC compared with exsmokers with normal DLCO, providing evidence of the impact of mild or early stage emphysema and a better understanding of abnormal DLCO and hyperpolarised ³He MRI in ex-smokers without COPD. [ABSTRACT FROM AUTHOR]

An introduction is presents in which the editor discusses various reports within the issue including the chronic obstructive pulmonary disease diagnosis,its symptoms and treatment.