ABSTRACT
Chronic obstructive pulmonary disease (COPD) is a complex lung disease characterized by a combination of airway disease and emphysema. Emphysema is classified as centrilobular emphysema (CLE), paraseptal emphysema (PSE), or panlobular emphysema (PLE), and airway disease extends from the respiratory, terminal, and preterminal bronchioles to the central segmental airways. Although clinical computed tomography (CT) cannot be used to visualize the small airways, micro-CT has shown that terminal bronchiole disease is more severe in CLE than in PSE and PLE, and micro-CT findings suggest that the loss and luminal narrowing of terminal bronchioles is an early pathological change in CLE. Furthermore, the introduction of ultra-high-resolution CT has enabled direct evaluation of the proximal small (1 to 2-mm diameter) airways, and new CT analytical methods have enabled estimation of small airway disease and prediction of future COPD onset and lung function decline in smokers with and without COPD. This review discusses the literature on micro-CT and the technical advancements in clinical CT analysis for COPD. Hopefully, novel micro-CT findings will improve our understanding of the distinct pathogeneses of the emphysema subtypes to enable exploration of new therapeutic targets, and sophisticated CT imaging methods will be integrated into clinical practice to achieve more personalized management.
ABSTRACT
Objective/background: the prevalence of pulmonary nontuberculous mycobacterial [pNTM] disease, including Mycobacterium avium complex [MAC], varies widely according to geographic region. However, the factors that influence regional variations in pNTM disease prevalence remain unknown. This study was undertaken to examine whether environmental or occupational factors or host traits could influence regional variations in pNTM disease prevalence
Methods: we collected laboratory data on pulmonary tuberculosis [pTB] and pNTM from two hospitals in the West Harima area of Japan and five hospitals in Kyoto City, Japan from 2012 to 2013. We estimated microbiological pNTM disease prevalence by multiplying all pTB cases in each area with the ratio of pNTM cases and pTB cases at the survey hospitals in each area. We administered a standardized questionnaire to 52 patients and 120 patients with pulmonary MAC [pMAC] disease at Ako City Hospital and Kyoto University Hospital, respectively
Results: the estimated prevalence of microbiological pNTM disease in the West Harima area [85.4/ 100,000 population-years] was significantly higher than that observed in Kyoto City [23.6/100,000 population-years; p < .001]. According to multiple logistic regression analysis, in Ako City Hospital, primary [activities directly related to natural resources] and secondary industries [construction, mining, and manufacturing primary industry produce; odds ratio [OR] = 4.79; 95% confidence interval [CI]= 1.49 - 14.0; p = .007] and soil exposure [OR= 13.6; 95% CJ= 4.94 - 45.26; p < .001] were associated with pMAC disease
Conclusion: environmental factors, both industrial structures associated with occupational dust and environmental soil exposure, could influence the regional variations in pNTM disease prevalence