Journal article
Improved CT-based estimate of pulmonary gas trapping accounting for scanner and lung-volume variations in a multicenter asthmatic study
Journal of applied physiology (1985), Vol.117(6), pp.593-603
09/15/2014
DOI: 10.1152/japplphysiol.00280.2014
PMCID: PMC4157164
PMID: 25103972
Abstract
Lung air trapping is estimated via quantitative computed tomography (CT) using density threshold-based measures on an expiration scan. However, the effects of scanner differences and imaging protocol adherence on quantitative assessment are known to be problematic. This study investigates the effects of protocol differences, such as using different CT scanners and breath-hold coaches in a multicenter asthmatic study, and proposes new methods that can adjust intersite and intersubject variations. CT images of 50 healthy subjects and 42 nonsevere and 52 severe asthmatics at total lung capacity (TLC) and functional residual capacity (FRC) were acquired using three different scanners and two different coaching methods at three institutions. A fraction threshold-based approach based on the corrected Hounsfield unit of air with tracheal density was applied to quantify air trapping at FRC. The new air-trapping method was enhanced by adding a lung-shaped metric at TLC and the lobar ratio of air-volume change between TLC and FRC. The fraction-based air-trapping method is able to collapse air-trapping data of respective populations into distinct regression lines. Relative to a constant value-based clustering scheme, the slope-based clustering scheme shows the improved performance and reduced misclassification rate of healthy subjects. Furthermore, both lung shape and air-volume change are found to be discriminant variables for differentiating among three populations of healthy subjects and nonsevere and severe asthmatics. In conjunction with the lung shape and air-volume change, the fraction-based measure of air trapping enables differentiation of severe asthmatics from nonsevere asthmatics and nonsevere asthmatics from healthy subjects, critical for the development and evaluation of new therapeutic interventions.
Details
- Title: Subtitle
- Improved CT-based estimate of pulmonary gas trapping accounting for scanner and lung-volume variations in a multicenter asthmatic study
- Creators
- Sanghun Choi - Department of Mechanical and Industrial Engineering, The University of Iowa, Iowa City, Iowa; IIHR-Hydroscience & Engineering, The University of Iowa, Iowa City, Iowa; Department of Biomedical Engineering, The University of Iowa, Iowa City, IowaEric A Hoffman - Department of Biomedical Engineering, The University of Iowa, Iowa City, Iowa; Department of Radiology, The University of Iowa, Iowa City, Iowa; Department of Internal Medicine, The University of Iowa, Iowa City, IowaSally E Wenzel - Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh Pennsylvania; andMario Castro - Departments of Internal Medicine and Pediatrics, Washington University School of Medicine, St. Louis, MissouriChing-Long Lin - Department of Mechanical and Industrial Engineering, The University of Iowa, Iowa City, Iowa; IIHR-Hydroscience & Engineering, The University of Iowa, Iowa City, Iowa; ching-long-lin@uiowa.edu
- Resource Type
- Journal article
- Publication Details
- Journal of applied physiology (1985), Vol.117(6), pp.593-603
- DOI
- 10.1152/japplphysiol.00280.2014
- PMID
- 25103972
- PMCID
- PMC4157164
- NLM abbreviation
- J Appl Physiol (1985)
- ISSN
- 8750-7587
- eISSN
- 1522-1601
- Publisher
- United States
- Grant note
- U01 HL114494 / NHLBI NIH HHS P30 ES005605 / NIEHS NIH HHS R01 HL094315 / NHLBI NIH HHS U10 HL109257 / NHLBI NIH HHS R01 HL112986 / NHLBI NIH HHS S10 RR022421 / NCRR NIH HHS HL112986 / NHLBI NIH HHS P30 DK054759 / NIDDK NIH HHS HL064368 / NHLBI NIH HHS
- Language
- English
- Date published
- 09/15/2014
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Radiology; Mechanical Engineering; Internal Medicine
- Record Identifier
- 9984051555002771
Metrics
16 Record Views