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Background: The heterogeneous distribution of emphysema is a key feature of chronic obstructive pulmonary disease (COPD) patients that typically is evaluated using high-resolution chest computed tomography (HRCT). Oxygen-enhanced pulmonary magnetic resonance imaging (OEMRI) is a new method to obtain information regarding regional ventilation, diffusion, and perfusion in the lung without radiation exposure. We aimed to compare OEMRI with HRCT for the assessment of heterogeneity in COPD patients. Methods: Forty patients with stable COPD underwent quantitative HRCT, OEMRI, and pulmonary function tests, including arterial blood gas analysis. OEMRI was also performed on nine healthy control subjects. We measured the severity of emphysema (percent low attenuation volume; LAV%) in whole lungs and the standard deviations (SDs) of the LAV% values of 10 isovolumetric partitions (SD-LAV) as an index of cranial-caudal heterogeneity. Similarly, relative enhancement ratios of oxygen (RERs) in whole lungs from OEMRI and SD-RER were analyzed. Results: COPD patients showed a lower mean RER than control subjects (12.6% vs 22.0%, p<0.01). The regional heterogeneity of the RERs was not always consistent with the LAV distribution. Both the HRCT (LAV% and SD-LAV) and the OEMRI (RER and SD-RER) indices were significantly associated with the diffusion capacity (DLCO) and partial pressure of oxygen in arterial blood (PaO2). The PaO2 was associated only with the heterogeneity index of HRCT (SD-LAV) (R2 = 0.39); however, the PaO2 was associated with both the mean RER and heterogeneity (SD-RER) in the multivariate analysis (R2 = 0.38). Conclusions: OEMRI-derived parameters were directly associated with oxygen uptake in COPD patients. Although the OEMRI-derived parameters were not identical to the HRCT-derived parameters, the cranial-caudal heterogeneity in HRCT or OEMRI was complementary to that in evaluations of oxygen uptake in the lungs. Functional imaging seems to provide new insights into COPD pathophysiology without radiation exposure. [ABSTRACT FROM AUTHOR]

ABSTRACT Background and objective: Health-related quality of life (HRQoL) is important in the management of chronic obstructive pulmonary disease (COPD). In patients with emphysema, lung hyperinflation identified radiologically as shortening and flattening of the diaphragm is associated with impaired HRQoL. It remains unclear whether shortening of the diaphragm and/or alteration in chest wall shape are associated with reduced pulmonary function and HRQoL. Methods: Pulmonary function testing and chest computed tomography (CT) were performed, and the St. George's Respiratory Questionnaire (SGRQ) was administered to 123 patients with COPD. Using CT images, the ratio of volume of lung region adjacent to the diaphragm dome to total lung volume (DLV%) was evaluated as a novel CT index, and conventional indices, including percent low attenuation volume (LAV%), wall area percent (WA%), total lung volume and diaphragm length (Ldi) were calculated. Results: DLV% was significantly correlated with Ldi. DLV% and Ldi were inversely correlated with lung hyperinflation, assessed as the ratio of residual volume to total lung capacity, independent of LAV% and WA%. Unlike Ldi, DLV% was inversely associated with all components and total scores for the SGRQ, independent of the severity of emphysema and airflow limitation. Conclusions: Reduced lung volume around the diaphragm correlated with lung hyperinflation and HRQoL, independent of emphysema severity. This needs to be verified in additional studies. [ABSTRACT FROM AUTHOR]

Background: Cigarette smoke is the main risk factor for emphysema, which is a key pathology in chronic obstructive pulmonary disease (COPD). Low attenuation areas (LAA) in computed tomography (CT) images reflect emphysema, and the cumulative size distribution of LAA clusters follows a power law characterized by the exponent D. This property of LAA clusters can be explained by model simulation, where mechanical force breaks alveolar walls causing local heterogeneous lung tissue destruction. However, a longitudinal CT study has not investigated whether continuous smoking causes the spatially heterogeneous progression of emphysema. Methods: We measured annual changes in ratios of LAA (LAA%), D and numbers of LAA clusters (LAN) in CT images acquired at intervals of ≥3 years from 22 current and 31 former smokers with COPD to assess emphysema progression. We constructed model simulations using CT images to morphologically interpret changes in current smokers. Results: D was decreased in current and former smokers, whereas LAA% and LAN were increased only in current smokers. The annual changes in LAA%, D, and LAN were greater in current, than in former smokers (1.03 vs. 0.37%, p = 0.008; - 0.045 vs. -0.01, p = 0.004; 13.9 vs. 1.1, p = 0.007, respectively). When LAA% increased in model simulations, the coalescence of neighboring LAA clusters decreased D, but the combination of changes in D and LAN in current smokers could not be explained by the homogeneous emphysema progression model despite cluster coalescence. Conversely, a model in which LAAs heterogeneously increased and LAA clusters merged somewhat in relatively advanced emphysematous regions could reflect actual changes. Conclusions: Susceptibility to parenchymal destruction induced by continuous smoking is not uniform over the lung, but might be higher in local regions of relatively advanced emphysema. These could result in the spatially heterogeneous progression of emphysema in current smokers. [ABSTRACT FROM AUTHOR]

Pharmacological lung volume reduction in COPD is an important goal in treatment with long-acting bronchodilators because in addition to airflow limitation, lung hyperinflation considerably affects COPD symptoms. Quantitative computed tomography (CT) simultaneously provides structural information about airway dimensions, emphysematous changes, and lung volumes, some of which are difficult to be evaluated by pulmonary function. Here, we evaluated changes in CT parameters and pulmonary function in 30 patients with COPD who underwent CT scans before and one year after starting tiotropium treatment and in 12 patients with COPD who were not treated with long-acting bronchodilators. Baseline pulmonary function and CT parameters did not differ between the two groups. One-year tiotropium therapy improved physiological-indices including residual volume (RV) and ratio of RV to total lung capacity (RV/TLC) (−235 mL, p = 0.005, and −2.9%, p = 0.0001, respectively), and CT-indices including wall area percent (WA%) and inner luminal area in right upper lobe apical and lower lobe basal segmental bronchi (−1.59%, p = 0.01, 2.27 mm2, p = 0.0005; and −1.33%, p = 0.0008, 3.42 mm2, p < 0.0001, respectively), low attenuation volume (LAV) and total lung volume (CT-TLV) (−92 mL, p = 0.0003, and −211 mL, p = 0.002, respectively). Changes in LAV, CT-TLV, RV, and RV/TLC were significantly greater in the tiotropium, than the non-bronchodilator group. The tiotropium-induced reduction in LAV correlated with the decrease in RV (ρ = 0.45, p = 0.01). Our findings not only indicate the value of the comprehensive CT measurements in assessing the effects of bronchodilators, including pharmacological lung volume reduction, but also further understanding of the structural changes underlying physiological improvements induced by bronchodilators. [ABSTRACT FROM AUTHOR]

Background: COPD pathology involves not only the lungs but also extrapulmonary abnormalities. Osteoporosis is one of the most important abnormalities because it may cause vertebral compression fractures and deteriorate pulmonary function. COPD patients have many risk factors for osteoporosis, such as low BMI, decreased activity, systemic inflammation, and use of corticosteroids. Some of these factors have been shown to deteriorate with COPD exacerbations. We previously demonstrated the correlation between emphysema and osteoporosis and between emphysema progression and COPD exacerbations. Thus, the hypothesis that exacerbation causes osteoporosis progression in COPD patients was investigated. Methods: Forty-two COPD patients not on osteoporosis treatment for over 2 years were recruited. During follow-up, exacerbations had been prospectively recorded. Thoracic vertebral bone mineral density (BMD) was measured using chest CT, and the annual change in BMD was calculated. The change was compared between patients with and without a history of exacerbations. Results: The decrease in thoracic vertebral BMD was greater in patients with than in those without a history of exacerbations (median ΔBMD mg/ml⋅year: -3.78 versus -0.30, p = 0.02). Moreover, multivariate regression analysis showed that exacerbations and baseline PaO2 were independent predictors of the BMD decrease (R2 = 0.20, p = 0.007, and R2 = 0.09, p = 0.03, respectively) after adjustment for baseline age, smoking status, and airflow limitation. Conclusions: This is the first longitudinal study to demonstrate that COPD exacerbations are independently associated with osteoporosis progression. Osteoporosis progression should be evaluated in COPD patients, especially in those with a history of frequent exacerbations. [ABSTRACT FROM AUTHOR]

Background: Recent evidence suggests that YKL-40, also called chitinase-3-like-1 protein, is involved in the pathogenesis of asthma and chronic obstructive pulmonary disease (COPD). Details of sputum YKL-40 in asthma and COPD, however, remain unknown. Objectives: To clarify associations of sputum YKL-40 levels with clinical indices in asthma and COPD. Methods: Thirty-nine patients with asthma, 14 age-matched never-smokers as controls, 45 patients with COPD, and 7 age-matched smokers as controls were recuited for this study. Sputum YKL-40 levels were measured and YKL-40 expression in sputum cells was evaluated by immunocytochemistry. Results: Sputum YKL-40 levels were higher in patients with COPD (346 ± 325 ng/ml) than in their smoker controls (125 ± 122 ng/ml; p < 0.05), but were not significantly different between patients with asthma (117 ± 170 ng/ml) and their controls (94 ± 44 ng/ml; p = 0.15). In patients with asthma only, sputum YKL-40 levels were positively correlated with disease severity (r = 0.34, p = 0.034) and negatively correlated with pre- and postbronchodilator %FEV1 (r = -0.47 and -0.42, respectively; p < 0.01) and forced mid-expiratory flow (r = -0.48 and -0.46, respectively, p < 0.01). Sputum YKL-40 levels were positively correlated with sputum neutrophil counts in asthma (r = 0.55, p < 0.001) and with neutrophil and macrophage counts in COPD (r = 0.45 and 0.65, respectively, p < 0.01). YKL-40 was expressed in the cytoplasm of sputum neutrophils and macrophages in all groups. Conclusions: Elevated sputum YKL-40 reflects airflow obstruction in asthma whereas the roles of YKL-40 in the proximal airways in COPD remain to be elucidated. Copyright © 2011 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

The article focuses on a study which investigated the relationship between computed tomography (CT) scan emphysema finding and mortality among patients with chronic obstructive pulmonary disease (COPD). The study included 251 outpatients with stable COPD, of whom 79 died. Study authors concluded that emphysematous findings on CT scan can predict respiratory mortality in outpatients with COPD.

Background: Health status, dyspnea and psychological status are important clinical outcomes in chronic obstructive pulmonary disease (COPD). However, forced expiratory volume in one second (FEV1) measured by spirometry, the standard measurement of airflow limitation, has only a weak relationship with these outcomes in COPD. Recently, in addition to spirometry, impulse oscillometry (IOS) measuring lung resistance (R) and reactance (X) is increasingly being used to assess pulmonary functional impairment. Methods: We aimed to identify relationships between IOS measurements and patient-reported outcomes in 65 outpatients with stable COPD. We performed pulmonary function testing, IOS, high-resolution computed tomography (CT), and assessment of health status using the St. George's Respiratory Questionnaire (SGRQ), dyspnea using the Medical Research Council (MRC) scale and psychological status using the Hospital Anxiety and Depression Scale (HADS). We then investigated the relationships between these parameters. For the IOS measurements, we used lung resistance at 5 and 20 Hz (R5 and R20, respectively) and reactance at 5 Hz (X5). Because R5 and R20 are regarded as reflecting total and proximal airway resistance, respectively, the fall in resistance from R5 to R20 (R5-R20) was used as a surrogate for the resistance of peripheral airways. X5 was also considered to represent peripheral airway abnormalities. Results: R5-R20 and X5 were significantly correlated with the SGRQ and the MRC. These correlation coefficients were greater than when using other objective measurements of pulmonary function, R20 on the IOS and CT instead of R5-R20 and X5. Multiple regression analyses showed that R5-R20 or X5 most significantly accounted for the SGRQ and MRC scores. Conclusions: IOS measurements, especially indices of peripheral airway function, are significantly correlated with health status and dyspnea in patients with COPD. Therefore, in addition to its simplicity and non-invasiveness, IOS may be a useful clinical tool not only for detecting pulmonary functional impairment, but also to some extent at least estimating the patient's quality of daily life and well-being. [ABSTRACT FROM AUTHOR]

The article explores the association between pulmonary emphysema and osteoporosis evaluated by computed tomography (CT) in patients with chronic obstructive pulmonary disease (COPD). Results reveal that the degree of pulmonary emphysema significantly correlated with reduced bone density. The findings suggest that COPD itself could be a risk factor for osteoporosis and that chest CT scanning is useful to menage COPD as a systemic disease.

Background and objective: Chest CT has been widely used for the evaluation of structural changes in lung parenchyma and airways in cross-sectional studies. There has been no report on the annual changes in airway dimensions as assessed by CT in COPD patients. The objective of this study was to investigate the annual changes in airway dimensions and lung attenuation using CT in patients with COPD and to evaluate the correlations among annual changes in CT measurements and pulmonary function. Methods: Eighty-three men with COPD had completed five annual assessments of CT scans and pulmonary function tests over 4 years. Airway dimensions of the basal segment bronchi and lung attenuation on CT images were analysed in 38 subjects in whom the same airway could be measured at least three times, including at entry and at the end of the study. Results: Mean annual decline in FEV1 was 21 mL/year. Annual changes in the percentage of low attenuation areas were not significantly correlated with decline in FEV1. On the other hand, annual changes in the percentage of wall area (WA%/year) were significantly inversely correlated with annual changes in FEV1 ( r = −0.363, P = 0.025), whereas WA%/year did not differ among severity stages at entry and did not correlate with baseline FEV1. Conclusions: The results showing that annual changes in airway thickening correlated with annual decline in air flow limitation suggests the importance of treatment of airway inflammation in COPD. CT is a useful tool for quantitative estimation not only of emphysema but also of airway lesions in longitudinal studies. [ABSTRACT FROM AUTHOR]

Background: Small airways may have an important role in asthma but are more difficult to assess pathologically than central airways. Computed tomographic indices of lung density are assumed to reflect air trapping and may be a useful noninvasive measure of small airways disease, but their pathophysiological relevance remains undetermined. Objective: To evaluate lung density on high-resolution computed tomography and examine its correlations with clinical and physiologic variables in 29 patients with stable asthma. Methods: Both lungs were scanned at full-inspiratory and full-expiratory phases to quantify percentage of lung field occupied by low attenuation area (LAA%; < −960 Hounsfield units) and mean lung density. Asthma severity, pulmonary function, methacholine airway sensitivity and reactivity, and sputum eosinophil counts were evaluated. Results: The mean lung density increased and LAA% decreased in all patients at expiratory phase compared with inspiratory phase. The inspiratory density indices and expiratory mean lung density correlated only with FEV1/forced vital capacity (FVC). Expiratory LAA% correlated more strongly than other variables with FEV1/FVC and with indices of peripheral airflow obstruction. Expiratory/inspiratory ratios of LAA% and mean lung density correlated, the former more strongly, with disease severity, residual volume/total lung capacity, and airway sensitivity, as well as with indices of global (FEV1 and FEV1/FVC) and peripheral airflow obstruction. Conclusion: Expiratory/inspiratory high-resolution computed tomography is useful for assessing small airways disease in asthma. Small airways involvement is associated with airflow obstruction, airway hypersensitivity, and more severe disease. Clinical implications: Small airways are an important therapeutic target in asthma. [Copyright &y& Elsevier]

Objective: It is not well known whether there is heterogeneity in the airway dimensions at different anatomic locations in individual patients with COPD. The first objective was to compare airway dimensions of the basal segment bronchus between COPD patients and healthy controls. The second and third objectives were to compare the airway dimensions in two anatomic locations, and to investigate the relationship between CT measurements and pulmonary function among COPD patients. Methods: Thirty males with COPD (aged 68.7 ± 8.1 years) and 18 healthy males (aged 64.9 ± 14.0 years) were enrolled in the study. COPD was diagnosed according to the criteria of the Global Initiative for Obstructive Lung Disease Workshop Report. Pulmonary function tests and CT scans were performed on all subjects. Airway dimensions and lung attenuation were automatically determined using methods that were validated with a phantom. Results: Age, smoking index and height did not significantly differ between the COPD patients and healthy controls. The COPD patients had a significantly thicker airway wall than healthy controls. Among the COPD patients, there were no significant differences in the airway dimensions of bronchi in different segments; however, the airway and lung attenuation measurements of the lower lung field were more strongly correlated with FEV1 than those of the upper lung field. Conclusion: Patients with COPD had no significant heterogeneity in airway dimensions at different anatomic locations. The airway and lung attenuation measurements of the lower lung field were more strongly correlated with airflow limitation than those of the upper lung field. [ABSTRACT FROM AUTHOR]

Abstract: Background: Studies exploring the association between emphysema detected on chest computed tomography (CT) and lung cancer have yielded mixed results. Our objective was to systematically review the evidence for this association. Methods: We searched MEDLINE, EMBASE and the Cochrane Library for the terms “lung cancer”, “emphysema” and “computed tomography” without language restriction. Bibliographies were also reviewed and authors contacted for additional information. Human studies in which CTs were performed and assessed for emphysema and in which subjects were evaluated systematically for lung cancer were included. Qualitative synthesis of evidence was performed followed by pooling of effect estimates using a random-effects model. Results: Of 187 citations, 7 were included in the qualitative synthesis and 5 in the meta-analysis. Three studies assessing emphysema visually observed an association with lung cancer, independent of smoking history and airflow obstruction. Three studies using densitometry to detect emphysema found no association with lung cancer. Another study directly comparing automated and visual emphysema detection techniques found only the latter to associate with lung cancer. Among 7368 subjects included in the meta-analysis, 2809 had emphysema on CT and 870 were diagnosed with lung cancer. The pooled adjusted odds ratio for lung cancer in the presence of emphysema on CT was 2.11 (95% CI 1.10–4.04); stratification by detection method yielded OR of 3.50 (95% CI 2.71–4.51) with visually detected emphysema and 1.16 (95% CI 0.48–2.81) with densitometric emphysema. Conclusion: Systematic literature review shows emphysema detected visually on CT to be independently associated with increased odds of lung cancer. This association did not hold with automated emphysema detection. [Copyright &y& Elsevier]