A Combined Pulmonary-Radiology Workshop for Visual Evaluation of COPD: Study Design, Chest CT Findings and Concordance with Quantitative Evaluation

Abstract

The purposes of this study were: to describe chest CT findings in normal non-smoking controls and cigarette smokers with and without COPD; to compare the prevalence of CT abnormalities with severity of COPD; and to evaluate concordance between visual and quantitative chest CT (QCT) scoring Methods Volumetric inspiratory and expiratory CT scans of 294 subjects, including normal non-smokers, smokers without COPD, and smokers with GOLD Stage I-IV COPD, were scored at a multi-reader workshop using a standardized worksheet. There were fifty-eight observers (33 pulmonologists, 25 radiologists); each scan was scored by 9–11 observers. Interobserver agreement was calculated using kappa statistic. Median score of visual observations was compared with QCT measurements. Results Interobserver agreement was moderate for the presence or absence of emphysema and for the presence of panlobular emphysema; fair for the presence of centrilobular, paraseptal, and bullous emphysema subtypes and for the presence of bronchial wall thickening; and poor for gas trapping, centrilobular nodularity, mosaic attenuation, and bronchial dilation. Agreement was similar for radiologists and pulmonologists. The prevalence on CT readings of most abnormalities (e.g. emphysema, bronchial wall thickening, mosaic attenuation, expiratory gas trapping) increased significantly with greater COPD severity, while the prevalence of centrilobular nodularity decreased. Concordances between visual scoring and quantitative scoring of emphysema, gas trapping and airway wall thickening were 75%, 87% and 65%, respectively. Conclusions Despite substantial inter-observer variation, visual assessment of chest CT scans in cigarette smokers provides information regarding lung disease severity; visual scoring may be complementary to quantitative evaluation.

Impaired Left Ventricular Filling in COPD and Emphysema: Is It the Heart or the Lungs?

“…We assessed emphysema quantitatively, which has much greater precision than radiologist assessment but for which a standard threshold of normality is currently lacking. 58,59 Therefore, we used an arbitrary but reasonable threshold of the median value of percent emphysema. Sensitivity anal yses showed that results were similar using a 25th percentile threshold and using a 2 950 HU definition (median or 25th percentile) to defi ne percent emphysema.…”

Progress in Imaging COPD, 2004 - 2014

“…In the COPDGene® workshop, where 58 observers independently scored CT scans of 294 individuals, agreement on pattern and extent of emphysema was poor to moderate, and concordance between visual and quantitative assessment of the presence of emphysema was only 75%. 61 Gietema, et al, found that in those with less severe categories of emphysema, radiologists tended to visually underestimate extent of emphysema compared with quantitative measures, while in those with more severe emphysema, the radiologists tended to relatively overestimate emphysema extent. Thus, QCT and visual evaluation may provide complementary, independent assessments of severity of emphysema, particularly in those with less severe abnormality.…”

Classification of Emphysema Subtypes: Comparative Assessment of Local Binary Patterns and Related Texture Features

“…To precisely investigate the relationship between emphysema subtypes and airflow limitation, extent of emphysema subtypes should be evaluated. Although it is possible to assess emphysema subtypes visually, the visual assessment was time-consuming and suffered from inter-observer variability [7]. To overcome these problems, automated CT quantification of emphysema subtypes should be pursued, which would provide additional benefits with radiologists.…”

“…However, visual assessment of emphysema is subjective and time-consuming, and suffers from inter-observer variability [7]. For example, kappa values for detection of centrilobular emphysema (CLE), panlobular emphysema, and paraseptal emphysema (PSE) ranged from 0.29 to 0.59 [7], and the inter-observer variability in emphysema subtypes was not acceptable. Under these circumstances, importance of automated CT quantification of emphysema has been recognized, which provides objective and reproducible evaluation of COPD.…”

“…Goddard et al [5] proposed scoring system for visual assessment of pulmonary emphysema, and the scoring system had been utilized in previous study [6]. However, visual assessment of emphysema is subjective and time-consuming, and suffers from inter-observer variability [7]. For example, kappa values for detection of centrilobular emphysema (CLE), panlobular emphysema, and paraseptal emphysema (PSE) ranged from 0.29 to 0.59 [7], and the inter-observer variability in emphysema subtypes was not acceptable.…”