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Dynamic Multiscale Boundary Conditions for 4D CT of Healthy and Emphysematous Rats

Changes in the shape of the lung during breathing determine the movement of airways and alveoli, and thus impact airflow dynamics. Modeling airflow dynamics in health and disease is a key goal for predictive multiscale models of respiration. Past efforts to model changes in lung shape during breathi...

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Detalles Bibliográficos
Autores principales: Jacob, Richard E., Carson, James P., Thomas, Mathew, Einstein, Daniel R.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3683027/
https://www.ncbi.nlm.nih.gov/pubmed/23799057
http://dx.doi.org/10.1371/journal.pone.0065874
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author Jacob, Richard E.
Carson, James P.
Thomas, Mathew
Einstein, Daniel R.
author_facet Jacob, Richard E.
Carson, James P.
Thomas, Mathew
Einstein, Daniel R.
author_sort Jacob, Richard E.
collection PubMed
description Changes in the shape of the lung during breathing determine the movement of airways and alveoli, and thus impact airflow dynamics. Modeling airflow dynamics in health and disease is a key goal for predictive multiscale models of respiration. Past efforts to model changes in lung shape during breathing have measured shape at multiple breath-holds. However, breath-holds do not capture hysteretic differences between inspiration and expiration resulting from the additional energy required for inspiration. Alternatively, imaging dynamically – without breath-holds – allows measurement of hysteretic differences. In this study, we acquire multiple micro-CT images per breath (4DCT) in live rats, and from these images we develop, for the first time, dynamic volume maps. These maps show changes in local volume across the entire lung throughout the breathing cycle and accurately predict the global pressure-volume (PV) hysteresis. Male Sprague-Dawley rats were given either a full- or partial-lung dose of elastase or saline as a control. After three weeks, 4DCT images of the mechanically ventilated rats under anesthesia were acquired dynamically over the breathing cycle (11 time points, ≤100 ms temporal resolution, 8 cmH(2)O peak pressure). Non-rigid image registration was applied to determine the deformation gradient – a numerical description of changes to lung shape – at each time point. The registration accuracy was evaluated by landmark identification. Of 67 landmarks, one was determined misregistered by all three observers, and 11 were determined misregistered by two observers. Volume change maps were calculated on a voxel-by-voxel basis at all time points using both the Jacobian of the deformation gradient and the inhaled air fraction. The calculated lung PV hysteresis agrees with pressure-volume curves measured by the ventilator. Volume maps in diseased rats show increased compliance and ventilation heterogeneity. Future predictive multiscale models of rodent respiration may leverage such volume maps as boundary conditions.
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spelling pubmed-36830272013-06-24 Dynamic Multiscale Boundary Conditions for 4D CT of Healthy and Emphysematous Rats Jacob, Richard E. Carson, James P. Thomas, Mathew Einstein, Daniel R. PLoS One Research Article Changes in the shape of the lung during breathing determine the movement of airways and alveoli, and thus impact airflow dynamics. Modeling airflow dynamics in health and disease is a key goal for predictive multiscale models of respiration. Past efforts to model changes in lung shape during breathing have measured shape at multiple breath-holds. However, breath-holds do not capture hysteretic differences between inspiration and expiration resulting from the additional energy required for inspiration. Alternatively, imaging dynamically – without breath-holds – allows measurement of hysteretic differences. In this study, we acquire multiple micro-CT images per breath (4DCT) in live rats, and from these images we develop, for the first time, dynamic volume maps. These maps show changes in local volume across the entire lung throughout the breathing cycle and accurately predict the global pressure-volume (PV) hysteresis. Male Sprague-Dawley rats were given either a full- or partial-lung dose of elastase or saline as a control. After three weeks, 4DCT images of the mechanically ventilated rats under anesthesia were acquired dynamically over the breathing cycle (11 time points, ≤100 ms temporal resolution, 8 cmH(2)O peak pressure). Non-rigid image registration was applied to determine the deformation gradient – a numerical description of changes to lung shape – at each time point. The registration accuracy was evaluated by landmark identification. Of 67 landmarks, one was determined misregistered by all three observers, and 11 were determined misregistered by two observers. Volume change maps were calculated on a voxel-by-voxel basis at all time points using both the Jacobian of the deformation gradient and the inhaled air fraction. The calculated lung PV hysteresis agrees with pressure-volume curves measured by the ventilator. Volume maps in diseased rats show increased compliance and ventilation heterogeneity. Future predictive multiscale models of rodent respiration may leverage such volume maps as boundary conditions. Public Library of Science 2013-06-14 /pmc/articles/PMC3683027/ /pubmed/23799057 http://dx.doi.org/10.1371/journal.pone.0065874 Text en © 2013 Jacob et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Jacob, Richard E.
Carson, James P.
Thomas, Mathew
Einstein, Daniel R.
Dynamic Multiscale Boundary Conditions for 4D CT of Healthy and Emphysematous Rats
title Dynamic Multiscale Boundary Conditions for 4D CT of Healthy and Emphysematous Rats
title_full Dynamic Multiscale Boundary Conditions for 4D CT of Healthy and Emphysematous Rats
title_fullStr Dynamic Multiscale Boundary Conditions for 4D CT of Healthy and Emphysematous Rats
title_full_unstemmed Dynamic Multiscale Boundary Conditions for 4D CT of Healthy and Emphysematous Rats
title_short Dynamic Multiscale Boundary Conditions for 4D CT of Healthy and Emphysematous Rats
title_sort dynamic multiscale boundary conditions for 4d ct of healthy and emphysematous rats
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3683027/
https://www.ncbi.nlm.nih.gov/pubmed/23799057
http://dx.doi.org/10.1371/journal.pone.0065874
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