Quantification and visualization of anisotropy in trabecular bone

Ketcham, Richard A.; Ryan, Timothy M.

doi:10.1111/j.1365-2818.2004.01277.x

Cited by 155 publications

(180 citation statements)

References 27 publications

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“…Regional variation has never been investigated in strepsirhine primate vertebral bodies. Also, in light of concerns raised about measuring the degree of anisotropy in arbitrary volumes (Ketcham and Ryan, 2004;Gosman and Ketcham, 2009), we felt it important to perform another analysis that would provide an alternative view on the relationships between positional behavior and trabecular bone architecture. We measured BV/TV, Tb.Th, Tb.N, and the MIL-DA with the Quant3D method.…”

Section: Methodsmentioning

confidence: 99%

“…Quant3D measures trabecular number as the number of intersections between the bone surface and a superimposed grid of lines normalized by the grid line length (Ryan and Krovitz, 2006;Gosman and Ketcham, 2009). Finally, the degree of anisotropy was measured in each spherical volume using Quant3D's mean intercept length module (Ketcham and Ryan, 2004). As already described, this module uses a directed secant sampling method to quantify the degree of anisotropy in three dimensions.…”

Section: Methodsmentioning

confidence: 99%

“…We also performed regional analyses of the cranial (cr) and caudal (ca) vertebral body trabecular bone using Quant3D (Ketcham and Ryan, 2004). Analyses were performed in spherical VOI centrally positioned on the images representing the 20th percentile and 80th percentile slices of the vbVOI (Fig.…”

Section: Methodsmentioning

confidence: 99%

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Lumbar Vertebral Body Bone Microstructural Scaling in Small to Medium‐Sized Strepsirhines

Fajardo

DeSilva

Manoharan

et al. 2013

The Anatomical Record

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Bone mass, architecture, and tissue mineral density contribute to bone strength. As body mass (BM) increases any one or combination of these properties could change to maintain structural integrity. To better understand the structural origins of vertebral fragility and gain insight into the mechanisms that govern bone adaptation, we conducted an integrative analysis of bone mass and microarchitecture in the last lumbar vertebral body from nine strepsirhine species, ranging in size from 42 g (Microcebus rufus) to 2,440 g (Eulemur macaco). Bone mass and architecture were assessed via mCT for the whole body and spherical volumes of interest (VOI). Allometric equations were estimated and compared with predictions for geometric scaling, assuming axial compression as the dominant loading regime. Bone mass, microarchitectural, and vertebral body geometric variables predominantly scaled isometrically. Among structural variables, the degree of anisotropy (Tb.DA) was the only parameter independent of BM and other trabecular architectural variables. Tb.DA was related to positional behavior. Orthograde primates had higher average Tb.DA (1.60) and more craniocaudally oriented trabeculae while lorisines had the lowest Tb.DA (1.25), as well as variably oriented trabeculae. Finally, lorisines had the highest ratio of trabecular bone volume to cortical shell volume ($3x) and while there appears to be flexibility in this ratio, the total bone volume (trabecular þ cortical) scales isometrically (BM 1.23 , r 2 ¼ 0.93) and appears tightly constrained. The common pattern of isometry in our measurements leaves open the question of how vertebral bodies in strepsirhine species compensate for increased BM. Anat Rec,

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Lumbar Vertebral Body Bone Microstructural Scaling in Small to Medium‐Sized Strepsirhines

Fajardo

DeSilva

Manoharan

et al. 2013

The Anatomical Record

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“…The mean horizontal orientation of brine layers was computed at each temperature using the Quant3D code [Ketcham and Ryan, 2004;Ketcham, 2005], and the 3D image stacks rotated to align this direction with the y axis. To minimize the effect of image rotation on our analysis, we in fact rotated the raw output and then reapplied the preprocessing and segmentation.…”

Section: Percolation Anisotropymentioning

confidence: 99%

Pore space percolation in sea ice single crystals

et al. 2009

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[1] We have imaged sea ice single crystals with X-ray computed tomography, and characterized the thermal evolution of the pore space with percolation theory. Between À18°C and À3°C the porosity ranged from 2 to 12% and we found arrays of near-parallel intracrystalline brine layers whose connectivity and complex morphology varied with temperature. We have computed key porosity-dependent functions of classical percolation theory directly from the thermally driven pore space evolution of an individual sample. This analysis is novel for a natural material and provides the first direct demonstration of a connectivity threshold in the brine microstructure of sea ice. In previous works this critical behavior has been inferred indirectly from bulk property measurements in polycrystalline samples. From a finite-size scaling analysis we find a vertical critical porosity p c,v = 4.6 ± 0.7%. We find lateral anisotropy with p c,pll = 9 ± 2% parallel to the layers and p c,perp = 14 ± 4% perpendicular to them. Lateral connectivity is established at higher brine volumes by the formation of thin necks between the brine layers. We relate these results to measured anisotropy in the bulk dc conductivity and fluid permeability using a dual porosity conceptual model. Our results shed new light on the complex microstructure of sea ice, highlighting single crystal anisotropy and a step toward a realistic transport property model for sea ice based on percolation theory. We present full experimental details of our imaging and segmentation methodology based on a phase relation formulation more widely applicable to ice-solute systems.

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“…As Ketcham (2005a) found, spherical features must be at least 3 voxels in diameter to be detected, while elongated features may be detected even if their width is less than 1 voxel. Different software packages for fabric analyses and discrete feature measurements within single samples (size, shape, orientation and contact relationships) were created by Ketcham and Ryan (2004) and Ketcham (2005a,b).…”

Section: X-ray Computed Tomography In Soil Studies Characterization Omentioning

confidence: 99%

Application of X-ray computed tomography to soil science: A literature review

Taina¹,

Heck²,

Elliot³

2008

Can. J. Soil. Sci.

259

126

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T. R. 2008. Application of X-ray computed tomography to soil science: A literature review. Can. J. Soil Sci. 88: 1Á20. The study of the spatial configuration of soil, in its complexity, requires an understanding of the interrelations and interactions between the diverse soil constituents, at various levels of organization. Investigations of the spatial arrangement of the mineral and organic components of soil have benefited from the development of techniques for structural analysis. X-ray computed tomography (CT) is a non-destructive and non-invasive technique that has been successfully used for three-dimensional (3D) examination of soil. Valuable information has been obtained by the application of CT for the description and quantitative measurements of soil structure elements, especially of soil pores and pore network features. In many studies, X-ray CT has been used to investigate the hydro-physical characteristics of the soil, in a functional and temporal manner. A dynamic approach has also been utilized in the evaluation of the biotic factor influence on soil. The analysis of soil solid phases, by X-ray CT, has been challenging due to the similar X-ray attenuation of different solid constituents. However, the use of multiple X-ray energy levels has facilitated the discrimination of minerals in soil. The aim of this review and synthesis is to offer a perspective on the major issues related to application of the technique, general attempted solutions and possible directions in the utilization of X-ray CT in soil research. Relevant scanning parameters, procedures for CT image reconstruction, algorithms for the quantification of soil characteristics and results are presented for each type of application.Key words: X-ray computed tomography, energy level, spatial resolution, segmentation, soil mineral and organic constituents, soil physical and hydro-physical properties, soil biota Taina, I. A., Heck, R. J. et Elliot, T. R. 2008. Application de la tomographie aux rayons X a`la science du sol : survol de la litte´rature. Can. J. Soil Sci. 88: 1Á20. Pour e´tudier la configuration spatiale du sol dans toute sa complexite´, il faut comprendre les relations et les interactions des fractions du sol a`diffe´rents niveaux d'organisation. Les recherches sur l'organisation spatiale des couches mine´rales et organiques du sol ont profite´du de´veloppement de techniques d'analyse structurale. La tomographie aux rayons X assiste´e par ordinateur (TXAO) est une technique non destructive et non invasive qu'on a applique´e avec succe`s a`l'analyse tridimensionnelle du sol. L'usage de la TXAO pour de´crire et quantifier les e´le´ments structuraux du sol, surtout les pores et les particularite´s de leurs re´seaux, a permis de glaner quelques pre´cieuses informations. Maintes e´tudes rapportent qu'on s'est servi de la TXAO pour pre´ciser les proprie´te´s hydrophysiques du sol sur le plan fonctionnel ou temporel. On a aussi recouru a`une approche dynamique pour e´valuer l'influence des facteurs biotiques sur le sol. L'analyse des p...

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Quantification and visualization of anisotropy in trabecular bone

Cited by 155 publications

References 27 publications

Lumbar Vertebral Body Bone Microstructural Scaling in Small to Medium‐Sized Strepsirhines

Lumbar Vertebral Body Bone Microstructural Scaling in Small to Medium‐Sized Strepsirhines

Pore space percolation in sea ice single crystals

Application of X-ray computed tomography to soil science: A literature review

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