Three-Dimensional Local Measurements of Bone Strain and Displacement: Comparison of Three Digital Volume Correlation Approaches

2015 ◽  
Vol 137 (7) ◽  
Author(s):  
Marco Palanca ◽  
Gianluca Tozzi ◽  
Luca Cristofolini ◽  
Marco Viceconti ◽  
Enrico Dall'Ara

Different digital volume correlation (DVC) approaches are currently available or under development for bone tissue micromechanics. The aim of this study was to compare accuracy and precision errors of three DVC approaches for a particular three-dimensional (3D) zero-strain condition. Trabecular and cortical bone specimens were repeatedly scanned with a micro-computed tomography (CT). The errors affecting computed displacements and strains were extracted for a known virtual translation, as well as for repeated scans. Three DVC strategies were tested: two local approaches, based on fast-Fourier-transform (DaVis-FFT) or direct-correlation (DaVis-DC), and a global approach based on elastic registration and a finite element (FE) solver (ShIRT-FE). Different computation subvolume sizes were tested. Much larger errors were found for the repeated scans than for the virtual translation test. For each algorithm, errors decreased asymptotically for larger subvolume sizes in the range explored. Considering this particular set of images, ShIRT-FE showed an overall better accuracy and precision (a few hundreds microstrain for a subvolume of 50 voxels). When the largest subvolume (50–52 voxels) was applied to cortical bone, the accuracy error obtained for repeated scans with ShIRT-FE was approximately half of that for the best local approach (DaVis-DC). The difference was lower (250 microstrain) in the case of trabecular bone. In terms of precision, the errors shown by DaVis-DC were closer to the ones computed by ShIRT-FE (differences of 131 microstrain and 157 microstrain for cortical and trabecular bone, respectively). The multipass computation available for DaVis software improved the accuracy and precision only for the DaVis-FFT in the virtual translation, particularly for trabecular bone. The better accuracy and precision of ShIRT-FE, followed by DaVis-DC, were obtained with a higher computational cost when compared to DaVis-FFT. The results underline the importance of performing a quantitative comparison of DVC methods on the same set of samples by using also repeated scans, other than virtual translation tests only. ShIRT-FE provides the most accurate and precise results for this set of images. However, both DaVis approaches show reasonable results for large nodal spacing, particularly for trabecular bone. Finally, this study highlights the importance of using sufficiently large subvolumes, in order to achieve better accuracy and precision.

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Hong Wang ◽  
X. Sherry Liu ◽  
Bin Zhou ◽  
Ji Wang ◽  
Baohua Ji ◽  
...  

Currently, specimen-specific micro finite element (μFE) analysis based micro computed tomography (μCT) images have become a major computational tool for the assessment of the mechanical properties of human trabecular bone. Despite the fine characterization of the three-dimensional (3D) trabecular microstructure based on high-resolution μCT images, conventional μFE models with each voxel converted to an element are not efficient in predicting the nonlinear failure behavior of bone due to a prohibitive computational cost. Recently, a highly efficient individual trabecula segmentation (ITS)-based plate and rod (PR) modeling technique has been developed by substituting individual plates and rods with shell and beam elements, respectively. In this technical brief, the accuracy of novel PR μFE models was examined in idealized microstructure models over a broad range of trabecular thicknesses. The Young's modulus and yield strength predicted by simplified PR models strongly correlated with those of voxel models at various voxel sizes. The conversion from voxel models to PR models resulted in an ∼762-fold reduction in the largest model size and significantly accelerated the nonlinear FE analysis. The excellent predictive power of the PR μFE models, demonstrated in an idealized trabecular microstructure, provided a quantitative mechanical basis for this promising tool for an accurate and efficient assessment of trabecular bone mechanics and fracture risk.


2014 ◽  
Vol 695 ◽  
pp. 588-591
Author(s):  
Khairul Salleh Basaruddin ◽  
Ruslizam Daud

This study aims to investigate the influence of trabecular bone in human mandible bone on the mechanical response under implant load. Three dimensional voxel finite element (FE) model of mandible bone was reconstructed from micro-computed tomography (CT) images that were captured from bone specimen. Two FE models were developed where the first consists of cortical bone, trabecular bone and implants, and trabecular bone part was excluded in the second model. A static analysis was conducted on both models using commercial software Voxelcon. The results suggest that trabecular bone contributed to the strength of human mandible bone and to the effectiveness of load distribution under implant load.


2004 ◽  
Vol 339 (1-2) ◽  
pp. 125-130 ◽  
Author(s):  
A.C. Jones ◽  
A.P. Sheppard ◽  
R.M. Sok ◽  
C.H. Arns ◽  
A. Limaye ◽  
...  

2018 ◽  
Vol 5 (8) ◽  
pp. 180563 ◽  
Author(s):  
Chantal Nguyen ◽  
Kimberly J. Schlesinger ◽  
Timothy W. James ◽  
Kristin M. James ◽  
Robert L. Sah ◽  
...  

Osteoporosis, characterized by increased fracture risk and bone fragility, impacts millions of adults worldwide, but effective, non-invasive and easily accessible diagnostic tests of the disease remain elusive. We present a magnetic resonance (MR) technique that overcomes the motion limitations of traditional MR imaging to acquire high-resolution frequency-domain data to characterize the texture of biological tissues. This technique does not involve obtaining full two-dimensional or three-dimensional images, but can probe scales down to the order of 40 μm and in particular uncover structural information in trabecular bone. Using micro-computed tomography data of vertebral trabecular bone, we computationally validate this MR technique by simulating MR measurements of a ‘ratio metric’ determined from a few k -space values corresponding to trabecular thickness and spacing. We train a support vector machine classifier on ratio metric values determined from healthy and simulated osteoporotic bone data, which we use to accurately classify osteoporotic bone.


Author(s):  
Xiaowei S. Liu ◽  
X. Henry Zhang ◽  
Paul Sajda ◽  
Punam K. Saha ◽  
Felix W. Wehrli ◽  
...  

Osteoporosis is an age-related disease characterized by low bone mass and architectural deterioration. Other than bone volume fraction (BV/TV), microarchitecture of trabecular bone, such as trabecular type (rods or plates), connectivity, and orientation of the trabecular network is also believed to be important in governing the mechanical properties of trabecular bone. A recent study [1] showed that the microarchitecture alone affects elastic moduli of trabecular bone and, further, that trabecular plates make a far greater contribution than rods. In human vertebral trabecular bone, the roles of transverse vs. vertical rods in conferring mechanical properties of trabecular bone have been debated [2, 3]. It has been suggested that the role of transverse trabecular rod is critical in determining elastic modulus of vertebral trabecular bone. However, without explicit classifications of trabecular type, or orientation assessment at an individual trabecula level, it is not possible yet to test this hypothesis in human trabecular bone samples despite the development of three-dimensional (3D) micro computed tomography (μCT) and μCT based finite element (FE) models of human trabecular bone. With the newly developed technique of complete volumetric decomposition and individual trabecula based orientation analyses [4], now it is possible to quantitatively examine the contributions of trabecular rods of various orientations in the elastic properties of vertebral trabecular bone.


2007 ◽  
Vol 6 (4) ◽  
pp. 7290.2007.00022 ◽  
Author(s):  
Cristian T. Badea ◽  
Laurence W. Hedlund ◽  
Julie F. Boslego Mackel ◽  
Lan Mao ◽  
Howard A. Rockman ◽  
...  

The purpose of this study was to investigate the use of micro–computed tomography (micro-CT) for morphological and functional phenotyping of muscle LIM protein (MLP) null mice and to compare micro-CT with M-mode echocardiography. MLP null mice and controls were imaged using both micro-CT and M-mode echocardiography. For micro-CT, we used a custom-built scanner. Following a single intravenous injection of a blood pool contrast agent (Fenestra VC, ART Advanced Research Technologies, Saint-Laurent, QC) and using a cardiorespiratory gating, we acquired eight phases of the cardiac cycle (every 15 ms) and reconstructed three-dimensional data sets with 94-micron isotropic resolution. Wall thickness and volumetric measurements of the left ventricle were performed, and cardiac function was estimated. Micro-CT and M-mode echocardiography showed both morphological and functional aspects that separate MLP null mice from controls. End-diastolic and -systolic volumes were increased significantly three- and fivefold, respectively, in the MLP null mice versus controls. Ejection fraction was reduced by an average of 32% in MLP null mice. The data analysis shows that two imaging modalities provided different results partly owing to the difference in anesthesia regimens. Other sources of errors for micro-CT are also analyzed. Micro-CT can provide the four-dimensional data (three-dimensional isotropic volumes over time) required for morphological and functional phenotyping in mice.


2022 ◽  
Author(s):  
Jennifer C. Coulombe ◽  
Zachary K. Mullen ◽  
Ashton M. Wiens ◽  
Liam E. Fisher ◽  
Maureen E. Lynch ◽  
...  

Three-dimensional (3D) imaging of osteocyte lacunae has recently substantiated the connection between lacunar shape and size, and osteocyte age, viability, and mechanotransduction. Yet it remains unclear why individual osteocytes reshape their lacunae and how networks of osteocytes change in response to local alterations in mechanical loads. We evaluated the effects of local mechanical stimuli on osteocyte lacunar morphometrics in tibial cortical bone from young female mice flown on the Space Shuttle for ~13 days. We optimized scan parameters, using a laboratory-based submicrometer-resolution X-Ray Microscope, to achieve large ~ 0.3 mm3 fields of view with sufficient resolution (≥ 0.3 μm) to visualize and measure thousands of lacunae per scan. Our novel approach avoids large measurement errors that are inherent in 2D and enables a facile 3D solution as compared to the lower resolution from benchtop micro-computed tomography (CT) systems or the cost and inaccessibility of synchrotron-based CT. Osteocyte lacunae were altered following microgravity exposure in a region-specific manner: more elongated (+7.0% Stretch) in predominately tensile-loaded bone as compared to those in compressively-loaded regions. In compressively-loaded bone, lacunae formed in microgravity were significantly larger (+6.9% Volume) than in the same region formed on Earth. We also evaluated lacunar heterogeneity (i.e., spatial autocorrelation of lacunar morphometric parameters) via kriging models. These statistical models demonstrated that heterogeneity varied with underlying spatial contributors, i.e. the local mechanical and biological environment. Yet in the absence of gravitational loading, osteocyte lacunae in newly formed bone were larger and were collectively more homogenous than in bone formed on Earth. Overall, this study shows that osteocyte reshape their lacunae in response to changes, or absence, in local mechanical stimuli and different biological environments. Additionally, spatial relationships among osteocytes are complex and necessitate evaluation in carefully selected regions of interest and of large cell populations.


Author(s):  
Javier L. Lara ◽  
Pablo Higuera ◽  
Raul Guanche ◽  
Inigo J. Losada

This paper presents a numerical analysis of the interaction of waves with piles. A model called IH-FOAM, based on OpenFOAM®, is used. IH-FOAM is able to simulate and to absorb waves in three-dimensional domains, reducing the computational cost and extending the range of applicability of the CFD modelling to the study of offshore and coastal structures. In this work, a detailed analysis of mono and multi-piled structures is carried out. Several piles layouts are studied Wave run-up and forces have been studied for the multi-piled structures. Those magnitudes have been compared with the single piled structure pointing out the difference in the wave induced hydrodynamics and the non-linear interaction between the waves and the structures. The work contained in this paper presents a first step which will be extended in the future to analyse more complex layouts and the effects of broken waves.


PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0251873
Author(s):  
Marco Palanca ◽  
Giulia De Donno ◽  
Enrico Dall’Ara

The spine is the first site for incidence of bone metastasis. Thus, the vertebrae have a high potential risk of being weakened by metastatic tissues. The evaluation of strength of the bone affected by the presence of metastases is fundamental to assess the fracture risk. This work proposes a robust method to evaluate the variations of strain distributions due to artificial lesions within the vertebral body, based on in situ mechanical testing and digital volume correlation. Five porcine vertebrae were tested in compression up to 6500N inside a micro computed tomography scanner. For each specimen, images were acquired before and after the application of the load, before and after the introduction of the artificial lesions. Principal strains were computed within the bone by means of digital volume correlation (DVC). All intact specimens showed a consistent strain distribution, with peak minimum principal strain in the range -1.8% to -0.7% in the middle of the vertebra, demonstrating the robustness of the method. Similar distributions of strains were found for the intact vertebrae in the different regions. The artificial lesion generally doubled the strain in the middle portion of the specimen, probably due to stress concentrations close to the defect. In conclusion, a robust method to evaluate the redistribution of the strain due to artificial lesions within the vertebral body was developed and will be used in the future to improve current clinical assessment of fracture risk in metastatic spines.


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