Quantitative 3D Micro-CT Imaging of Human Lung Tissue

Kampschulte, Marian; Schneider, C.; Litzlbauer, H. D.; Tscholl, Dietmar; Zeiner, Carsten; Krombach, Gabriele A.; Ritman, Erik L.; Bohle, Rainer M.; Langheinrich, AC

doi:10.1055/s-0033-1355498

Cited by 19 publications

(9 citation statements)

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“…2). A tissue fraction ratio of 0.17 has been measured in nondecellularized samples of human lung obtained from autopsy using 3D micro-CT imaging [54]. Differences in tissue fraction ratio estimations might be due to differences in the lung architecture between human and rat, changes in sample preparation, and differences between 2D and 3D assessment of tissue fraction ratio.…”

Section: Discussionmentioning

confidence: 99%

Nonlinear elasticity of the lung extracellular microenvironment is regulated by macroscale tissue strain

et al. 2019

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The extracellular matrix (ECM) of the lung provides physical support and key mechanical signals to pulmonary cells. Although lung ECM is continuously subjected to different stretch levels, detailed mechanics of the ECM at the scale of the cell is poorly understood. Here, we developed a new polydimethylsiloxane (PDMS) chip to probe nonlinear mechanics of tissue samples with atomic force microscopy (AFM). Using this chip, we performed AFM measurements in decellularized rat lung slices at controlled stretch levels. The AFM revealed highly nonlinear ECM elasticity with the microscale stiffness increasing with tissue strain. To correlate micro-and macroscale ECM mechanics, we also assessed macromechanics of decellularized rat lung strips under uniaxial tensile testing. The lung strips exhibited exponential macromechanical behavior but with stiffness values one order of magnitude lower than at the microscale. To interpret the relationship between micro-and macromechanical properties, we carried out a finite element (FE) analysis which revealed that the stiffness of the alveolar cell microenvironment is regulated by the global strain of the lung scaffold. The FE modeling also indicates that the scale dependence of stiffness is mainly due to the porous architecture of the lung parenchyma. We conclude that

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Section: Discussionmentioning

confidence: 99%

Nonlinear elasticity of the lung extracellular microenvironment is regulated by macroscale tissue strain

et al. 2019

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“…The initial Womersley number, i.e., the Womersley number at time t * = 0, is taken to be Wo = 0.01, which roughly corresponds to a normal breathing rate and average alveolar duct dimensions. The initial porosity is taken to be ε 0 = 0.8, which is a typical value for the lung parenchyma (DeGroot and Straatman, 2016;Gehr et al, 1978;Kamschulte et al, 2013;Weibel, 1963). The amplitude of the wall motion is taken to be Λ w = 0.02329, yielding a typical 15% expansion in the fluid volume (Harding and Robinson, 2010;Sznitman et al, 2009).…”

Section: One-dimensional Results For Flow In An Alveolated Ductmentioning

confidence: 99%

“…(iii) The average porosity of the lung parenchyma is within the range ε = 0.7 to 0.9 (Gehr et al, 1978;Kamschulte et al, 2013;Weibel, 1963), such that ε ∼ O(1) and the deviation from this value is small (∆ε ≪ 1).…”

Section: Closure Of Momentum Equationmentioning

confidence: 99%

A Porous Media Model of Alveolar Duct Flow in the Human Lung

DeGroot

Straatman

2018

J Por Media

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Prediction of air flow in the human lung is of great interest for many physiological applications. Recent advances in modeling such flows using computational fluid dynamics have included the development of porous media-based approaches that consider the small-scale airways and alveoli as a porous domain. This article presents a derivation of the governing equations relevant to flow in an alveolated duct based on the theory of volume-averaging as well as their closure. It is shown that the momentum closure problem reduces to that of a steady-state problem which is solved over a representative unit cell of an alveolated duct to predict its permeability. The modeling approach is validated against permeability predictions coming from transient simulations of flow in an expanding and contracting duct. Finally, analytical expressions for the velocity and pressure in an alveolated duct are derived and presented.

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“…First, we found a high tissue percentage of 69.4% compared to 30.6% air‐filled space (expressed as fluid‐filled space in a fetal setting). In human adult lung, the tissue percentage is approximately 20% based on μ CT imaging using osmium as tissue contrast enhancement agent . This might be because of incomplete removal of liquid from the fetal lung or the inherent properties of the fetal lung at this specific lung developmental stage.…”

Section: Discussionmentioning

confidence: 99%