Cross-sectional Plane Research Articles

Use of a pin-penetration wood density meter to determine the density of 25 Indonesian species

The pin-penetration device is a minimally destructive instrument that is widely used to estimate the physical properties of wood, e.g., density, with advantages such as reduced testing times, low costs, and fewer defects induced in the wood being tested. In this study, such a device was used on 25 Indonesian hardwood species with a strength class (SC) distribution from SC II to IV (according to the Indonesian classification of wood SCs). Tests were conducted on three different orthogonal planes, i.e., cross-sectional, radial, and tangential planes. The wood density ranged from 0.28 to 0.88 g/cm3, and the specific gravity was 0.25 to 0.76. The cross-sectional plane penetration depth of the wood was significantly greater than that of either the radial or tangential plane, whereas the pin penetration values of the radial and tangential planes were not significantly different. A prediction model for predicting the density and specific gravity of wood via pin penetration showed a significant regression. Thus, the use of a pin-penetration device was found to be suitable for estimating wood density and specific gravity in a range of SCs of tropical wood species regardless of species.

Measurement and investigation of mechanical properties of a partial oxide dispersion strengthened Zircaloy-4 tube via an instrumented indentation test

The formation of a partial oxide dispersion strengthened (here denoted as P-ODS) layer on the surface of a Zircaloy-4 (Zry-4) tube is regarded as one of the effective ways to increase the strength of the Zry-4 tube at a bulk scale. This consequently enhances the resistance to ballooning and rupture under accident conditions. In this study, the mechanical properties such as the yield strength of a P-ODS Zry-4 tube at local scale were investigated by micro instrumented indentation testing (IIT). The P-ODS layer was formed on the surface of the Zry-4 tube by a laser beam scanning (LBS) method that uses Y2O3 particles. The IIT was performed at a cross-sectional plane of the P-ODS Zry-4 tube using a spherical indenter. Several regions, including the base Zry-4 tube and P-ODS layer, were considered as indentation points. As a result, the mechanical properties of the P-ODS Zry-4 tube at the local scale were effectively obtained from the IIT. Considerable strength enhancement of the P-ODS layer was observed by comparing with the base Zry-4 tube. Furthermore, the strength enhancement was studied using microstructure-based strengthening models such as Orowan and Hall-Petch to predict the amount of strengthening theoretically. From the suggested strengthening models, the strengthening of the P-ODS layer was effectively investigated, and the results can be useful for both fabricating and simulating the P-ODS Zry-4 tube.

Mechanical strain mapping of GaAs based VCSELs

We report an investigation of the strain field in mesa structures for oxide-confined vertical-cavity surface-emitting lasers (VCSELs) using the polarization-resolved micro-photoluminescence (PL) measurement of the degree of polarization (DOP) at room temperature. The DOP of the PL is correlated with the spatial distribution of the embedded anisotropic strain in a VCSEL structure. Measurements normal to (100) surfaces of the samples and from (110) cross-sectional planes were performed. The effect of two processes required in the fabrication of GaAs-based VCSELs was studied: the plasma etching of the P-doped distributed Bragg reflector and the wet oxidation process used to control current flow and lateral optical confinement. The DOP method allows very sensitive measurements of the mechanical strain (on the order of 10−5) accumulated in VCSEL devices even during different steps of the fabrication process.

2D cine vs. 3D self-navigated free-breathing high-resolution whole heart cardiovascular magnetic resonance for aortic root measurements in congenital heart disease

BackgroundCardiovascular magnetic resonance (CMR) is considered the method of choice for evaluation of aortic root dilatation in congenital heart disease. Usually, a cross-sectional 2D cine stack is acquired perpendicular to the vessel’s axis. However, this method requires a considerable patient collaboration and precise planning of image planes. The present study compares a recently introduced 3D self-navigated free-breathing high-resolution whole heart CMR sequence (3D self nav) allowing a multiplanar retrospective reconstruction of the aortic root as an alternative to the 2D cine technique for determination of aortic root diameters.MethodsA total of 6 cusp-commissure (CuCo) and cusp-cusp (CuCu) enddiastolic diameters were measured by two observers on 2D cine and 3D self nav cross-sectional planes of the aortic root acquired on a 1.5 T CMR scanner. Asymmetry of the aortic root was evaluated by the ratio of the minimal to the maximum 3D self nav CuCu diameter. CuCu diameters were compared to standard transthoracic echocardiographic (TTE) aortic root diameters.ResultsSixty-five exams in 58 patients (32 ± 15 years) were included. Typically, 2D cine and 3D self nav spatial resolution was 1.1–1.52 × 4.5-7 mm and 0.9–1.153 mm, respectively. 3D self nav yielded larger maximum diameters than 2D cine: CuCo 37.2 ± 6.4 vs. 36.2 ± 7.0 mm (p = 0.006), CuCu 39.7 ± 6.3 vs. 38.5 ± 6.5 mm (p < 0.001). CuCu diameters were significantly larger (2.3–3.9 mm, p < 0.001) than CuCo and TTE diameters on both 2D cine and 3D self nav. Intra- and interobserver variabilities were excellent for both techniques with bias of -0.5 to 1.0 mm. Intra-observer variability of the more experienced observer was better for 3D self nav (F-test p < 0.05). Aortic root asymmetry was more pronounced in patients with bicuspid aortic valve (BAV: 0.73 (interquartile (IQ) 0.69; 0.78) vs. 0.93 (IQ 0.9; 0.96), p < 0.001), which was associated to a larger difference of maximum CuCu to TTE diameters: 5.5 ± 3.3 vs. 3.3 ± 3.8 mm, p = 0.033.ConclusionBoth, the 3D self nav and 2D cine CMR techniques allow reliable determination of aortic root diameters. However, we propose to privilege the 3D self nav technique and measurement of CuCu diameters to avoid underestimation of the maximum diameter, particularly in patients with asymmetric aortic roots and/or BAV.

2D cine vs. 3D free-breathing self-navigated whole heart for aortic root measurements in congenital heart disease

Abstract Funding Acknowledgements Type of funding sources: None. Background Cardiac magnetic resonance is considered the method of choice for determination of aortic root diameters in congenital heart disease. Usually, a cross-sectional 2D cine stack is acquired perpendicular to the vessel’s axis. However, this method requires a considerable patient collaboration and precise planning of image planes. This study compares a recently introduced free-breathing high-resolution 3D self-navigating whole heart sequence (3D self nav) to the 2D cine technique for determination of aortic root diameters. Methods Two observers measured on 2D cine and 3D self nav cross-sectional planes of the aortic root (figure A and B), acquired on a 1.5T scanner, cusp-commissure (CuCo) and cusp-cusp (CuCu) enddiastolic diameters (figure B and C). Asymmetry of the aortic root was evaluated by the ratio of the minimal to maximum CuCu diameter. CuCu diameters were compared to transthoracic echocardiographic (TTE) aortic root diameters. Results 65 exams in 58 patients (mean age 32 ± 15y) were included. 2D cine and 3D self nav spatial resolution was 1.4x4.5-6mm and 1.1³mm, respectively. 3D self nav and CuCu yielded larger diameters than 2D cine and CuCo, respectively (table). Intra- and interobserver variabilities were excellent for both techniques ( bias -0.5 to 1.0 mm). Intra-observer variability of the experienced observer was better for 3D self nav (F-test p &amp;lt; 0.05). Aortic root asymmetry was more pronounced in patients with bicuspid aortic valve (BAV: 0.73 (0.69; 0.78) vs. 0.93 (0.9; 0.96), p &amp;lt; 0.001), which was associated with a larger difference of maximum CuCu to TTE diameters: 5.5 ± 3.3 vs. 3.3 ± 3.8 mm, p = 0.03. Conclusion Both, the 3D self nav and 2D cine techniques allow reliable determination of aortic root diameters. However, the 3D self nav technique and measurement of the CuCu diameters should be privileged to avoid underestimation of the maximum diameter, particularly in patients with asymmetric aortic roots and/or BAV 2D cine vs. 3D self nav CuCo min CuCo mid CuCo max CuCu min CuCu mid CuCu max Mean diameter 2D cine (mm) 33.5 34.8 36.2 33.4 37.6 38.5 Mean diameter 3D self nav (mm) 34.5 35.9 37.2 34.3 38.5 39.7 Mean difference (mm) -1.0 -1.1 -1.0 -0.8 -1.3 -1.2 95% Limits of agreement (mm) -5.1 to 3.2 -5.3 to 3.1 -5.5 to 3.5 -5.5 to 3.8 -4.7 to 2.0 -4.7 to 2.3 Standard deviation (mm) 3.2 2.1 2.3 2.4 1.7 1.8 Variance (mm2) 4.5 4.5 5.2 5.6 2.9 3.2 Pearson’s correlation (r) 0.952 0.954 0.945 0.944 0.972 0.951 P value (t-test) 0.003 0.001 0.006 0.005 &amp;lt;0.001 &amp;lt;0.001 Abstract Figure.

Forced oscillations of beams with installation (Part II)

This article (Part II) is a continuation of Part I, published in the same edition, where the spectral problem is considered. Part II examines two types of transverse beam oscillations: forced harmonic and forced random. The beam carries its own distributed mass and discrete mass. The source of oscillations is operating equipment with an element moving during technological operations. The mathematical model of oscillations is presented as a boundary value problem from the main partial differential equation of the hyperbolic type of the fourth order in the spatial coordinate, the second order in time, the boundary conditions and the conditions of the beam sections‘ conjugation. The technical theory of the rods‘ bending oscillations is used, based on Bernoulli‘s hypothesis about the beam plane cross-sections‘ invariability. The methods of variables separation and finite differences are applied. The algorithms for solving the problems have been developed, implemented in the Matlab software environment. Verification of the proposed mathematical models is demonstrated using the specific examples. The particular examples have been carried out and the practical conclusions have been outlined.

Three-dimensional spiral CT observation of the facet joints of the lower cervical spine and its clinical significance

ObjectiveBy observing the 3D anatomy of normal adult cervical facet joints, using the picture archiving and communication system to measure its 3D parameters and discussing its clinical significance, the aim of this study was to provide a reliable morphological basis for the design and manufacture of lower cervical facet joint interface distractors.MethodsWe selected 200 patients who underwent cervical spine 3D spiral computed tomography (CT) examination in the imaging department of our hospital from September 2019 to May 2020 and whose spiral CT images showed no cervical spinal canal stenosis, cervical disc herniation, obvious bone hyperplasia, or infection. The anterior and posterior diameters of the facet joints on both sides of the cervical spine, the space between the joints, and the left and right diameters were measured on the sagittal, cross-sectional and coronal planes after reconstruction with 3D spiral CT.ResultsThe anterior and posterior diameters of the facet joints of the cervical spine, the space between the joints, and the left and right diameters all increased from top to bottom along the cervical spine. The 3D parameters of the C2-3~C6-7 segments were significantly different between the male and female groups.ConclusionThe anteroposterior diameter, joint space interval, and left and right diameter of cervical facet joints are different in each segment and between the sexes. The lower cervical facet joint interface fusion device designed according to the measurement results can fully meet the needs of most patients.

Secondary Currents with Scour Hole at Grade Control Structures

Most studies on local scouring at grade control structures have principally focused on the analysis of the primary flow field, predicting the equilibrium scour depth. Despite the numerous studies on scouring processes, secondary currents were not often considered. Based on comprehensive measurements of flow velocities in clear water scours downstream of a grade control structure in a channel with non-cohesive sediments, in this study, we attempted to investigate the generation and turbulence properties of secondary currents across a scour hole at equilibrium condition. The flow velocity distributions through the cross-sectional planes at the downstream location of the maximum equilibrium scour depth clearly show the development of secondary current cells. The secondary currents form a sort of helical-like motion, occurring in both halves of the cross-section in an axisymmetric fashion. A detailed analysis of the turbulence intensities and Reynolds shear stresses was carried out and compared with previous studies. The results highlight considerable spatial heterogeneities of flow turbulence. The anisotropy term of normal stresses dominates the secondary shear stress, giving the impression of its crucial role in generating secondary flow motion across the scour hole. The anisotropy term shows maximum values near both the scour mouth and the scour bed, caused, respectively, by the grade control structure and the sediment ridge formation, which play fundamental roles in maintaining and enhancing the secondary flow motion.

CFD prediction of shell-side flow and mass transfer in regular fiber arrays

Numerical simulations were conducted for fully developed, steady-state flow with mass transfer in fiber bundles arranged in regular lattices. The porosity was 0.5 and the Schmidt number 500. Several combinations of axial flow, transverse flow and flow attack angles in the cross-section plane were considered. The axial and transverse Reynolds numbers Rez, ReT were made to vary from 10−4 to 102. Concentration boundary conditions, and the definition of an average Sherwood number, were addressed. Results for the hydraulic permeability were compared with the literature. Both hexagonal and square lattices were found to be hydraulically almost isotropic up to transverse flow Reynolds numbers ReT of ~10, while they behaved anisotropically in regard to mass transfer even at ReT as low as 0.1. A larger anisotropy was exhibited by the square lattice. In mixed (axial+transverse) flow, the transverse friction coefficient was almost completely unaffected by the simultaneous presence of axial flow, while the axial friction coefficient (and thus the axial pressure loss) increased with the transverse Reynolds number for ReT>~5-10. In regard to mass transfer, the Sherwood number settled in all cases to the higher between the Sherwood number in purely transverse flow and that in purely axial flow.

Rearrangements in the Conformational Structure of Polypeptides on the Surface of a Metal Nanowire in Rotating Electric Field: Molecular Dynamics Simulation

Molecular dynamics has been employed to study conformational rearrangements of polyampholytic and uniformly charged polypeptides adsorbed on the surface of a transversely polarized nanowire, in particular, upon rotation of the polarizing electric field vector. On the surface of the transversely polarized nanowire, a fringe consisting of polyampholitic polypeptide macromolecules is protruded in the direction of polarization, while uniformly charged polypeptide is shifted to the polarized regions of the cross section that are charged oppositely to the charge of macrochain units. The larger the distance between oppositely charged units in the polyampholytic polypeptide, the higher the ratio between the fringe thicknesses in the direction of polarization and in the orthogonal direction in the cross section plane. In an electric field rotating around the axis of the metal nanowire, uniformly charged polypeptides adsorbed on its surface rotate around the wire in the same direction. The same phenomenon has been observed for polyampholytic polypeptides, in which the distances between negatively and positively charged units in macrochains are longer than the half-circumference of the nanowire.

Dynamic Stability of a Three-Layer Beam – Generalization of the Sandwich Structures Theory

The subject of the study is a simply supported three-layer beam of the length L, width b and total depth h subjected to a pulsating axial force (Fig.1). The individual hypothesis-theory of deformation of the plane cross section is assumed for the purpose of modelling of the beam with consideration of the shear effect in the layers. The hypothesis is a generalization of the classical sandwich theory – broken line hypothesis (Fig.2).

A new cone-beam computed tomography dosimetry method providing optimal measurement positions: A Monte Carlo study

The conventional weighted computed tomography dose index (CTDIw) may not be suitable for cone-beam computed tomography (CBCT) dosimetry because a cross-sectional dose distribution is angularly inhomogeneous owing to partial angle irradiations. This study was conducted to develop a new dose metric (f(0)CBw) for CBCT dosimetry to determine a more accurate average dose in the central cross-sectional plane of a cylindrical phantom using Monte Carlo simulations. First, cross-sectional dose distributions of cylindrical polymethyl methacrylate phantoms over a wide range of phantom diameters (8-40cm) were calculated for various CBCT scan protocols. Then, by obtaining linear least-squares fits of the full datasets of the cross-sectional dose distributions, the optimal radial positions, which represented measurement positions for the average phantom dose, were determined. Finally, the f(0)CBw method was developed by averaging point doses at the optimal radial positions of the phantoms. To demonstrate its validity, the relative differences between the average doses and each dose index value were estimated for the devised f(0)CBw, conventional CTDIw, and Haba's CTDIw methods, respectively. The relative differences between the average doses and each dose index value were within 4.1%, 16.7%, and 11.9% for the devised, conventional CTDIw, and Haba's CTDIw methods, respectively. The devised f(0)CBw value was calculated by averaging four "point doses" at 90° intervals and the optimal radial positions of the cylindrical phantom. The devised method can estimate the average dose more accurately than the previously developed CTDIw methods for CBCT dosimetry.

Three-point bending of beams with consideration of the shear effect

The subject of the paper pertains to simply supported beams with bisymmetrical cross sections under three-point bending with consideration of the shear effect. The deformation of a planar cross section of the beam is described taking into account the assumed nonlinear hypothesis-theory. Two differential equations of equilibrium are obtained based on the principle of stationary potential energy. This system is analytically solved and the shear coefficients and deflections of the beams are derived. Moreover, the Young's modules of the materials and deflections of the beams are experimentally determined on a test stand. The results of the studies are specified in tables and compared.

Simulation tests of selected gas flow parameters through combustion engine valves

The article presents the numerical analysis of a single-cylinder gasoline engine with indirect injection and spark ignition. The goal is to recognize and analyze gas flow through inlet and outlet valves and channels. These data were obtained from the simulation of a four-cycle engine cycle without combustion of the fuel-air mixture. The simulation was carried out in ANSYS, using a dedicated IC Engine module. After the simulation, the result was analyzed on the cross-sectional plane of both the valves and the combustion chamber. This method provided the necessary and concise representation of the flow characteristics. Five separate stages are presented - two describing the different displacement of the valve for each inlet and exhaust stroke and one representing the phenomenon of overlapping. The type of flow, its speed and tendency to create turbulence are described

OH visualization of ethylene combustion modes in the exhaust of a fundamental, supersonic combustor

Abstract This work examined combustion modes in a fundamental, axisymmetric, supersonic combustor at flight equivalent Mach numbers ranging from 7.5 to 9.0. Ethylene was injected at a variety of mass flow rates to examine both scram-mode, jet wake stabilized and dual-mode combustion. At higher flight Mach number conditions, the fuelling rate required to transition from scram-mode to dual-mode combustion increased. Distributions of the OH radical were observed using planar laser-induced fluorescence (PLIF) in a cross-sectional plane immediately downstream of the combustor exit, and analyzed according to their variation in the radial and circumferential dimensions. It was observed that radial centroids of the ring-like OH PLIF signal for the scram-mode cases approached the centerline linearly with increasing equivalence ratio, but the dual-mode cases appeared to randomly fluctuate in the observed exhaust cross-section. The distributions of scram- and dual-mode cases were clustered in specific regions on plots of circumferential variation as a function of radial centroid, with a jet wake stabilized case appearing between the two clusters. These clusters may be used to help identify scram- and dual-mode combustion in future experiments.

Peak Flow in Model Aorta Through Bi-Leaflet Mechanical Heart Valve with Varying Orientation.

This study aims to numerically investigate the effect of bi-leaflet mechanical heart valve (BMHV) orientation on flow pattern in a realistic human aorta model with branches. The aorta model geometry is based on anatomical shape and dimensions involving aortic arch with twist and branches. Unsteady numerical simulations have been carried out to investigate the peak systolic flow in aorta through a BMHV installed at three different orientations, marked as 0°, 45°, and 90°. Velocity, vorticity, and strain fields were obtained in various cross sectional planes for all the cases to examine the spatial flow evolution starting from the sinus along the aortic arch. The valve leaflets were seen to produce small-scale stream wise contra-rotating vortices. These vortices changed their positions around the axis of aorta while advecting from one cross-sectional plane to another; thereby, clearly indicating swirl in the aortic flow. The net viscous dissipation energy loss (EL), obtained from strain field, was found to rise because of the presence of BMHV. The increase in the EL varied depending on the valve orientation as it changed from 43% for 0° to a maximum of 53% for 90° compared with no valve case. Similarly, the wall shear stress registered an increase by up to 4 Pa in the ascending aorta because the presence of BMHV; however, no significant effect of the valve orientation was noticed.

The anatomic basis for ultrasound in the diagnosis and treatment of styloid process-related diseases.

BackgroundThe styloid process (SP), stylohyoid ligament and lesser horn of hyoid bone together form the stylohyoid chain. Differences in the ossification degree and the connection sites of each segment of the stylohyoid chain on both sides lead to variations in the length, orientation, thickness, and straightness of SP. The incidence of elongation of the SP, known as styloid process syndrome (SPS), is around 4%, with only 4% of patients showing elongation show symptoms. Computed tomography (CT) remains the first-choice auxiliary examination for diagnosing SPS, but its performance can be affected by a variety of factors. Ultrasound can reveal the parapharyngeal space and adjacent structures, which offer high consistency with CT findings. Here, we investigated the ultrasonographic features of the SP and its adjacent structures in normal adults and assessed the clinical utility of ultrasound assessment for SP-related diseases.MethodsWith the ramus of mandible, mastoid process, SP, and salivary gland as the anatomical landmarks, ultrasonography was conducted on the parapharyngeal space in 78 healthy adults. The scans were performed along the oblique coronal section of the ramus and the cross-sectional plane between the mastoid process and ramus to visualize the SP and its adjacent structures. The SP length, the shortest distance from the SP tip to the outer edge of tonsil (SP-tonsil distance), and the distance from SP to the internal carotid artery (SP–ICA distance) were measured.ResultsSP and its adjacent structures were successfully visualized on ultrasonography in all 78 subjects. The measured SP length was 2.65±0.48 cm. The SP–tonsil distance was 1.95±0.50 cm. The SP–ICA distance was 0.509±0.231 cm. The SP length and SP–tonsil distance measured by ultrasound were not significantly different from those measured by CT (P=0.071, P=0.053). Furthermore, the SP length and SP–tonsil distance measured by ultrasound were positively correlated with CT measurements (r=0.917, P=0.071; r=0.978, P=0.053, respectively). SP–tonsil distance was negatively correlated with SP length and SP inward deflection angle.ConclusionsUltrasound can accurately reveal the shape and size of SP and its adjacent structures and thus will be helpful for the diagnosis of SP-related diseases.

Stochastic methods for the neutron transport equation II: Almost sure growth

The neutron transport equation (NTE) describes the flux of neutrons across a planar cross-section in an inhomogeneous fissile medium when the process of nuclear fission is active. Classical work on the NTE emerges from the applied mathematics literature in the 1950s through the work of R. Dautray and collaborators (Méthodes Probabilistes Pour les équations de la Physique (1989) Eyrolles; Mathematical Analysis and Numerical Methods for Science and Technology. Vol. 6: Evolution Problems. II (1993) Springer; Mathematical Topics in Neutron Transport Theory: New Aspects (1997) World Scientific). The NTE also has a probabilistic representation through the semigroup of the underlying physical process when envisaged as a stochastic process (cf. Méthodes Probabilistes pour les équations de la Physique (1989) Eyrolles; Introduction to Monte-Carlo Methods for Transport and Diffusion Equations (2003) Oxford Univ. Press; IMA J. Numer. Anal. 26 (2006) 657–685; Publ. Res. Inst. Math. Sci. 7 (1971/72) 153–179). More recently, Cox et al. (J. Stat. Phys. 176 (2019) 425–455) and Cox et al. (2019) have continued the probabilistic analysis of the NTE, introducing more recent ideas from the theory of spatial branching processes and quasi-stationary distributions. In this paper, we continue in the same vein and look at a fundamental description of stochastic growth in the supercritical regime. Our main result provides a significant improvement on the last known contribution to growth properties of the physical process in (Publ. Res. Inst. Math. Sci. 7 (1971/72) 153–179), bringing neutron transport theory in line with modern branching process theory such as (Ann. Probab. 44 (2016) 235–275; Ann. Probab. 43 (2015) 2545–2610). An important aspect of the proofs focuses on the use of a skeletal path decomposition, which we derive for general branching particle systems in the new context of nonlocal branching generators.

Bistability and hidden attractors in the paradigmatic Rössler'76 system.

In this paper, the dynamics of the paradigmatic Rössler system is investigated in a yet unexplored region of its three-dimensional parameter space. We prove a necessary condition in this space for which the Rössler system can be chaotic. By using standard numerical tools, like bifurcation diagrams, Poincaré sections, and first-return maps, we highlight both asymptotically stable limit cycles and chaotic attractors. Lyapunov exponents are used to verify the chaotic behavior while random numerical procedures and various plane cross sections of the basins of attraction of the coexisting attractors prove that both limit cycles and chaotic attractors are hidden. We thus obtain previously unknown examples of bistability in the Rössler system, where a point attractor coexists with either a hidden limit cycle attractor or a hidden chaotic attractor.

Lobar Ventilation in Patients with COPD Assessed with the Full-Scale Airway Network Flow Model and Xenon-enhanced Dual-Energy CT.

Background The full-scale airway network (FAN) flow model shows excellent agreement with limited functional imaging data but requires further validation prior to clinical use. Purpose To validate the ventilation distributions computed with the FAN flow model with xenon ventilation from xenon-enhanced dual-energy (DE) CT in participants with chronic obstructive pulmonary disease (COPD). Materials and Methods In this prospective study, the FAN model extracted structural data from xenon-enhanced DE CT images of men with COPD scanned between June 2012 and July 2013 to compute gas ventilation dynamics. The ventilation distributions on the middle cross-section plane, percentage lobar ventilation, and ventilation heterogeneity quantified by the coefficient of variation (CV) were compared between xenon-enhanced DE CT imaging and the FAN model. The relationship between the ventilation parameters with the densitometry and pulmonary function test results was demonstrated. The agreements and correlations between the parameters were measured using the concordance correlation coefficient and the Pearson correlation coefficient. Results Twenty-two men with COPD (mean age, 67 years ± 7 [standard deviation]) were evaluated. The percentage lobar ventilation computed with FAN showed a strong positive correlation with xenon-enhanced DE CT data (r = 0.7, P < .001). Ninety-five percent of lobar ventilation CV differences lay within 95% confidence intervals. Correlations of the percentage lobar ventilation were negative for percentage emphysema (xenon-enhanced DE CT: r = -0.38, P < .001; FAN: r = -0.23, P = .02) but were positive for percentage normal tissue volume (xenon-enhanced DE CT: r = 0.78, P < .001; FAN: r = 0.45, P < .001). Lung CVs of FAN revealed negative correlations with the spirometry results (CVFAN vs percentage predicted forced expiratory volume in 1 second: r = -0.75, P < .001; CVFAN vs ratio of forced expiratory volume in 1 second to forced vital capacity: r = -0.67, P < .001). Conclusion The full-scale airway network modeled lobar ventilation in patients with chronic obstructive pulmonary disease correlated with the xenon-enhanced dual-energy CT imaging data. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Parraga and Eddy in this issue.