Journal article
Disproportionate contribution of right middle lobe to emphysema and gas trapping on computed tomography
PloS one, Vol.9(7), pp.e102807-e102807
2014
DOI: 10.1371/journal.pone.0102807
PMCID: PMC4108372
PMID: 25054539
Abstract
Given that the diagnosis of chronic obstructive pulmonary disease (COPD) relies on demonstrating airflow limitation by spirometry, which is known to be poorly sensitive to early disease, and to regional differences in emphysema, we sought to evaluate individual lobar contributions to global spirometric measures.
Subjects with COPD were compared with smokers without airflow obstruction, and non-smokers. Emphysema (% low attenuation area, LAAinsp<-950 HU, at end-inspiration) and gas trapping (%LAAexp<-856 HU at end-expiration) on CT were quantified using density mask analyses for the whole lung and for individual lobes, and distribution across lobes and strength of correlation with spirometry were compared.
The right middle lobe had the highest %LAAinsp<-950 HU in smokers and controls, and the highest %LAAexp<-856 HU in all three groups. While RML contributed to emphysema and gas trapping disproportionately to its relatively small size, it also showed the least correlation with spirometry. There was no change in correlation of whole lung CT metrics with spirometry when the middle lobe was excluded from analyses. Similarly, RML had the highest %LAAexp<-856 HU while having the least correlation with spirometry.
Because of the right middle lobe's disproportionate contribution to CT-based emphysema measurements, and low contribution to spirometry, longitudinal studies of emphysema progression may benefit from independent analysis of the middle lobe in whole lung quantitative CT assessments. Our findings may also have implications for heterogeneity assessments and target lobe selection for lung volume reduction.
ClinicalTrials.gov NCT00608764.
Details
- Title: Subtitle
- Disproportionate contribution of right middle lobe to emphysema and gas trapping on computed tomography
- Creators
- Surya P Bhatt - Division of Pulmonary and Critical Care Medicine, University of Iowa, Iowa City, Iowa, United States of AmericaJessica C Sieren - Departments of Radiology and Biomedical Engineering, University of Iowa, Iowa City, Iowa, United States of AmericaJohn D Newell Jr - Departments of Radiology and Biomedical Engineering, University of Iowa, Iowa City, Iowa, United States of AmericaAlejandro P Comellas - Division of Pulmonary and Critical Care Medicine, University of Iowa, Iowa City, Iowa, United States of AmericaEric A Hoffman - Departments of Radiology and Biomedical Engineering, University of Iowa, Iowa City, Iowa, United States of America
- Resource Type
- Journal article
- Publication Details
- PloS one, Vol.9(7), pp.e102807-e102807
- DOI
- 10.1371/journal.pone.0102807
- PMID
- 25054539
- PMCID
- PMC4108372
- NLM abbreviation
- PLoS One
- ISSN
- 1932-6203
- eISSN
- 1932-6203
- Publisher
- Public Library of Science; United States
- Grant note
- P30 ES005605 / NIEHS NIH HHS U01 HL089856 / NHLBI NIH HHS U01 HL089897 / NHLBI NIH HHS R01 HL089856 / NHLBI NIH HHS R01 HL64368 / NHLBI NIH HHS P30 DK054759 / NIDDK NIH HHS R01 HL064368 / NHLBI NIH HHS
- Language
- English
- Date published
- 2014
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Radiology; Pulmonary, Critical Care, and Occupational Medicine; ICTS; Internal Medicine
- Record Identifier
- 9984051794402771
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