Chest
Original ResearchCOPDAirway Count and Emphysema Assessed by Chest CT Imaging Predicts Clinical Outcome in Smokers
Section snippets
Materials and Methods
The study and manuscript were approved according to the procedures of the LTRC detailed elsewhere.9 This study was also approved by the Institutional Review Board at Brigham and Women's Hospital.
Reliability of Airway Counts
The intra- and interreader reproducibility of airway counts was high, as suggested by the intraclass correlation coefficients. The intraclass correlation coefficients for the TAC and the individual sixth AG, seventh AG, and eight AG were 0.98, 0.85, 0.95, and 0.97 for the intrareader assessments and 0.97, 0.75, 0.90, and 0.86 for the interreader assessments, respectively (Fig 2).
Population Description
Baseline characteristics of the 50 subjects by emphysema groups are shown in Table 1. Subjects with ≥ 25% emphysema
Discussion
In this study of a subset of subjects enrolled in the LTRC, we performed a detailed visual assessment of the third through eighth AG arising from the RB1. There was an inverse association among the TAC, the airway count of the sixth AG to the eighth AG of RB1, and emphysema. Although TAC and airway counts of the sixth AG to the eighth AG were directly related to both spirometric measures of lung function and the distance walked by a subject in 6 min, they were inversely related to both mMRC
Conclusions
In summary, the total CT imaging-based count of airways present in the sixth through eighth AG (TAC) of a subset of smokers enrolled in the LTRC was inversely related to densitometric measures of emphysema and was also a predictor of a high BODE index. This latter observation suggests that CT imaging airway count may be a unique COPD-related clinically relevant phenotype. Additional investigation is needed in a larger sample to further explore the clinical significance of emphysema-associated
Acknowledgments
Author contributions: Dr Diaz: contributed to the writing and final approval of the manuscript.
Dr Valim: contributed to the statistical analysis and the writing and final approval of the manuscript.
Dr Yamashiro: contributed to the reading of CT scans for the reproducibility analysis of visual airway count, and to the writing and final approval of the manuscript.
Dr San José Estépar: contributed to software development, which allowed the CT imaging analysis of emphysema, and to the writing and
References (33)
The pathogenesis of pulmonary emphysema
Am J Med
(1958)- et al.
Selection of appropriate computed tomographic image reconstruction algorithms for a quantitative multicenter trial of diffuse lung disease
J Comput Assist Tomogr
(2008) - et al.
“Density mask”. An objective method to quantitate emphysema using computed tomography
Chest
(1988) - et al.
Comparison of Plethysmographic and helium dilution lung volumes: which is best for COPD?
Chest
(2010) - et al.
The measurement of dyspnea. Contents, interobserver agreement, and physiologic correlates of two new clinical indexes
Chest
(1984) - et al.
The pathology of chronic obstructive pulmonary disease
Annu Rev Pathol
(2009) The histology of generalized pulmonary emphysema. II. Diffuse emphysema
Australas Ann Med
(1957)- et al.
The centrilobular form of hypertrophic emphysema and its relation to chronic bronchitis
Thorax
(1957) - et al.
The number and dimensions of small airways in emphysematous lungs
Am J Pathol
(1972) - et al.
Small airway obstruction in COPD [abstract]
Am J Respir Crit Care Med
(2009)
Micro-computed tomography measurements of peripheral lung pathology in chronic obstructive pulmonary disease
Proc Am Thorac Soc
Bronchial morphometry in smokers: comparison with healthy subjects by using 3D CT
Eur Radiol
Clinical significance of radiologic characterizations in COPD
COPD
Complexity of terminal airspace geometry assessed by lung computed tomography in normal subjects and patients with chronic obstructive pulmonary disease
Proc Natl Acad Sci U S A
Comparison of computed density and macroscopic morphometry in pulmonary emphysema
Am J Respir Crit Care Med
Automated measurement of single and total lung volume from CT
J Comput Assist Tomogr
Cited by (66)
Filtering spatial point patterns using kernel densities
2021, Spatial StatisticsObstructions in the lower airways lead to altered airflow patterns in the central airway
2020, Respiratory Physiology and NeurobiologyDirect evaluation of peripheral airways using ultra-high-resolution CT in chronic obstructive pulmonary disease
2019, European Journal of Radiology
Funding/Support: This work was supported by the National Institutes of Health [Grants K23HL089353-01A1 and U01089856] and by a grant from the Parker B. Francis Foundation.
Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (http://www.chestpubs.org/site/misc/reprints.xhtml).