In patients with airflow limitation caused by cigarette smoking, lung density measured by computed tomography is strongly correlated with quantitative pathology scores of emphysema, but the ability of lung densitometry to detect progression of emphysema is disputed. We assessed the sensitivity of lung densitometry as a parameter of disease progression of emphysema in comparison to FEV(1) and gas transfer. At study baseline and after 30 months we measured computed tomography (CT)-derived lung density, spirometry and carbon monoxide diffusion coefficient in 144 patients with chronic obstructive pulmonary disease (COPD) in five different centers. Annual change in lung density was 1.31 g/L/year (CI 95%: -2.12 to -0.50 HU, p=0.0015, 39.5 mL/year (CI 95%: -100.0-21.0 mL, p=0.2) for FEV(1) (-39.5 mL) and 24.3 micromol/min/kPa/L/year for gas transfer (CI 95%: -61.0-12.5 micromol/min/kPa/L/year, p=0.2). Signal-to-noise ratio (mean change divided by standard error of the change) for the detection of annual change was 3.2 for lung densitometry, but 1.3 for both FEV(1) and gas diffusion. We conclude that detection of progression of emphysema was found to be 2.5-fold more sensitive using lung densitometry than by using currently recommended lung function parameters. Our results support CT scan as an efficacious test for novel drugs for emphysema.
To explore if change in the extent of emphysema correlated with change in lung function, the effect of resection of emphysematous tissue was studied by computed tomography (CT) densitometry. In addition, the current authors studied how surgery-induced change in emphysema related to lung density in control subjects.In total, 30 patients (14 females; mean¡SD age 59¡10 yrs) with severe emphysema before and 3 months after lung volume reduction surgery (LVRS), 48 patients with moderate emphysema and 76 control subjects were investigated. Lung density (15th percentile point) of both lungs and heterogeneity of lung density between 12 isovolumetric partitions in each lung were calculated from chest CT images.The 15th percentile point and its heterogeneity could distinguish controls from subjects with moderate emphysema with a sensitivity and specificity of .95%. LVRS significantly increased lung density by 5.0¡10.9 g?L -1 (n530). Improvement in the diffusing capacity of the lung for carbon monoxide and in residual volume significantly correlated with an increase in lung density (n520 and 28, respectively). Change in forced expiratory volume in one second did not correlate with change in lung density.In conclusion, lung density 15th percentile point is a valuable surrogate marker for detection of both the extent of and reduction in emphysema.
In view of the fact that the effects after real and sham acupuncture compared to controls who had no needling at all were small, in all likelihood clinically irrelevant, our data do not seem to support the use of acupuncture in the management of pharmacologically well-treated patients with mild-to-moderate persistent asthma.
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