Shape and Regularity of 3D Cortical Bone Canals: Comparaison Between Desktop and Synchrotron Radiation Micro-CT Images (original) (raw)
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Quantitative 3D analysis of the canal network in cortical bone by micro-computed tomography
Anatomical record. Part B, New anatomist, 2003
Cortical bone is perforated by an interconnected network of porous canals that facilitate the distribution of neurovascular structures throughout the cortex. This network is an integral component of cortical microstructure and, therefore, undergoes continual change throughout life as the cortex is remodeled. To date, the investigation of cortical microstructure, including the canal network, has largely been limited to the two-dimensional (2D) realm due to methodological hurdles. Thanks to continuing improvements in scan resolution, micro-computed tomography (muCT) is the first nondestructive imaging technology capable of resolving cortical canals. Like its application to trabecular bone, muCT provides an efficient means of quantifying aspects of 3D architecture of the canal network. Our aim here is to introduce the use of muCT for this application by providing examples, discussing some of the parameters that can be acquired, and relating these to research applications. Although seve...
Journal of Orthopaedic Science, 2007
Background. The porosity of human cortical bone is one of the major parameters conditioning bone strength. The purpose of this study was to validate the characterization of human cortical bone microarchitecture using microcomputed tomography (µCT). To validate this µCT technique, the structural measurements were compared with other methods such as ultrasonic techniques and scanning electron microscopy (SEM). Methods. Nineteen cortical samples were extracted from the superior, middle, and inferior shaft of three human femurs (FI, FII, FIII). The samples were scanned by µCT with an isotropic resolution of 8 µm. Most of the structural parameters used for trabecular microarchitecture were calculated to characterize the network of pores. On the same cortical samples, (1) ultrasound measurements were performed using contact transmission emitter-receptor to determine elastic coeffi cient and Young's modulus; (2) SEM was performed on femoral cross sections from FII to evaluate the porosity. Results. The morphological parameters showed a wide range of variation depending of the level of the diaphysis. Porosity measured by µCT was signifi cantly correlated with porosity measured by SEM (r = 0.91, P < 0.05). Moreover, all the morphological parameters showed high correlation coeffi cients with the elastic coeffi cient and Young's modulus, leading to validation of our three-dimensional analysis. Conclusions. The strong correlations between the structural and mechanical properties obtained with the three techniques allowed us to validate the µCT technique used to characterize cortical bone microstructure. Porosity measurements might be of importance for clinicians and researchers to obtain a better understanding and evaluation of bone fracture in elderly patients.
Three-dimensional analysis of cortical bone structure using X-ray micro-computed tomography
Physica A: Statistical Mechanics and its Applications, 2004
We demonstrate the capability of X-ray micro-computed tomography to image the microstructure of human cortical bone. At 5 m voxel size we observe the complex morphology of the Haversian network in three dimensions. The local thickness of Haversian canals is measured using a maximal sphere algorithm and found to have a bimodal signature and a mean radius of 19:2 m. The intra-cortical porosity due to Haversian canals is measured as 3.0%. Both results are in agreement with traditional histomorphometric measurements. We show that at higher resolutions one can resolve the spatial distribution of lacunae in cortical bone.
PLoS ONE, 2014
Objective: The objective of this study was to evaluate the relationship between the trabecular bone microarchitecture and cortical bone morphology by using micro-computed tomography (micro-CT) and dental cone-beam computed tomography (dental CT). Materials and Methods: Sixteen femurs and eight fifth lumbar vertebrae were collected from eight male Sprague Dawley rats. Four trabecular bone microarchitecture parameters related to the fifth lumbar vertebral body (percent bone volume [BV/TV], trabecular thickness [TbTh], trabecular separation [TbSp], and trabecular number [TbN]) were calculated using micro-CT. In addition, the volumetric cancellous bone grayscale value (vCanGrayscale) of the fifth lumbar vertebral body was measured using dental CT. Furthermore, four cortical bone morphology parameters of the femoral diaphysis (total crosssectional area [TtAr], cortical area [CtAr], cortical bone area fraction [CtAr/TtAr], and cortical thickness [CtTh]) were calculated using both micro-CT and dental CT. Pearson analysis was conducted to calculate the correlation coefficients (r) of the micro-CT and dental CT measurements. Paired-sample t tests were used to compare the differences between the measurements of the four cortical bone morphology parameters obtained using micro-CT and dental CT. Results: High correlations between the vCanGrayscale measured using dental CT and the trabecular bone microarchitecture parameters (BV/TV [r = 0.84] and TbTh [r = 0.84]) measured using micro-CT were observed. The absolute value of the four cortical bone morphology parameters may be different between the dental CT and micro-CT approaches. However, high correlations (r ranged from 0.71 to 0.90) among these four cortical bone morphology parameters measured using the two approaches were obtained. Conclusion: We observed high correlations between the vCanGrayscale measured using dental CT and the trabecular bone microarchitecture parameters (BV/TV and TbTh) measured using micro-CT, in addition to high correlations between the cortical bone morphology measured using micro-CT and dental CT. Further experiments are necessary to validate the use of dental CT on human bone.
Journal of Applied Physiology, 2013
Jast J, Jasiuk I. Age-related changes in the 3D hierarchical structure of rat tibia cortical bone characterized by high-resolution micro-CT. .-Three-dimensional hierarchical structure of female Sprague-Dawley rat tibia cortical bone was characterized as a function of age , and 72 wk) using a high-resolution micro-computed tomography. At the whole bone level, 3-wk samples exhibited statistically significant differences in a mean total tissue volume, mean cortical bone volume, mean cortical bone volume density, mean periosteal perimeter, and mean cortical thickness (P Ͻ 0.05) compared with all other ages. At the tissue level, there was a statistically significant increase in a mean canal number density and a decrease in a mean canal volume and diameter between 3-wk and 12-wk samples. While no significant variations were found between mean canal lengths, there was a dependence of mean canal orientation on age. At the cell level, there were no statistically significant differences in a lacuna number density and a lacuna volume density, and all lacunae element-based parameters displayed no dependence on age across age. In addition, at the microstructural level, the cannular indexes were reported separately for anterior, posterior, medial, and lateral anatomic regions. From 3 to 32 wk of age, there existed significantly fewer canals per volume of bone in the medial region of the tibia vs. other cross-sectional quadrants. Although there were changes with age, there were no statistically significant differences in the mean canal volume, mean canal diameter, and mean canal length between the four anatomic regions. cortical bone; bone's hierarchical structure; high-resolution microcomputed tomography; canal network; osteocyte lacunae
Comparison of Microcomputed Tomographic and Microradiographic Measurements of Cortical Bone Porosity
Calcified Tissue International, 2004
Cortical bone is perforated by a network of canals that have a significant impact upon its material properties. Microcomputed tomography offers the possibility of noninvasively visualizing and quantifying cortical pores in both two and three dimensions. Establishing how two-dimensional (2D) microcomputed tomographic (lCT) analysis compares with conventional methods for analyzing cortical porosity is an important prerequisite for the wider adoption of this technique and the development of three-dimensional (3D) analysis. Therefore, we compared porosity-related parameters from 2D microcomputed tomographic images with those from matching microradiographic sections. Samples from five human femora were scanned at a 10-lm resolution and then sequentially sectioned and microradiographed. An average of eight image pairs were produced from each femur (total, n = 41). The repeatability and comparability of the two techniques was assessed for three parameters; cortical porosity (%), mean pore area (lm 2 ), and pore density (pores/mm 2 ). For repeatability, no significant difference (P > 0.05) was found between the two methods for cortical porosity and mean pore area; however, pore density differed significantly (P < 0.001). For comparability, the bias (± error) between the methods was found to be 0.51% (±0.31%) for cortical porosity and )155 lm 2 (±293 lm 2 ) for mean pore area. The bias for pore density was dependent upon measurement size with microcomputed tomographic images having 14% (±9.3%) fewer pores per millimeter squared. The qualitative and quantitative similarities between the two techniques demonstrated the utility of 2D microcomputed tomographic for cortical porosity analysis. However, the relatively poor results for pore density revealed that a higher resolution (<10 lm) is needed to consistently visualize all cortical pores in human bone.
Journal of Bone and Mineral Research, 2013
ABSTRACTCurrent micro–computed tomography (µCT) systems allow scanning bone at resolutions capable of three‐dimensional (3D) characterization of intracortical vascular porosity and osteocyte lacunae. However, the scanning and reconstruction parameters along with the image segmentation method affect the accuracy of the measurements. In this study, the effects of scanning resolution and image threshold method in quantifying small features of cortical bone (vascular porosity, vascular canal diameter and separation, lacunar porosity and density, and tissue mineral density) were analyzed. Cortical bone from the tibia of Sprague‐Dawley rats was scanned at 1‐µm and 4‐µm resolution, reconstructions were density‐calibrated, and volumes of interest were segmented using approaches based on edge‐detection or histogram analysis. In 1‐µm resolution scans, the osteocyte lacunar spaces could be visualized, and it was possible to separate the lacunar porosity from the vascular porosity. At 4‐µm reso...
Effect of Voxel Size on 3D Micro-CT Analysis of Cortical Bone Porosity
Calcified Tissue International, 2007
This study examines the impact of voxel size on 3D micro-CT analysis of human cortical bone porosity. The study is based on computed microtomography scans of 10 human anterior femoral midshaft specimens acquired at 5, 10, and 15 lm voxel sizes. Artificial voxel sizes (10, 20, and 40 lm) were generated from the smallest scan voxel size (5 lm) in order to compare actual scanning with artificial degradation, a method employed in other similar studies. Canal volume fraction (CaV/TV), canal surface to volume ratio (CaS/ CaV), mean canal diameter (CaDm), mean canal separation (CaSp), canal number (CaN), degree of anisotropy (DA), and canal connectivity density (CaConnD) were calculated from matching volumes of interest for all datasets. Qualitatively, the clarity of the actual scan datasets deteriorated rapidly as voxel size increased. In contrast, within the artificially generated datasets, the clarity of cortical pores was better maintained until the largest voxel size (40 lm). Mean absolute percent error values, correlation coefficients, and paired t-tests revealed a pattern of increasing, and generally significant, differences between the smallest and progressively larger voxel sizes (both scanned and artificial). Relative to the actual scans, however, the artificial datasets were less sensitive to changing voxel size. These findings indicated that subtle changes in voxel size, within the range examined, have a considerable effect on human cortical porosity structural parameters. Additionally, the use of artificially increased voxel sizes should be viewed with caution as they may not reflect what can actually be obtained by scanning.
J Appl Physiol, 2006
The purpose of this study was to demonstrate the ability of computed microtomography based on monochromatic synchrotron radiation (SRμCT) in microstructural analysis of cortical bone. Tibial diaphyses of growing rats (14 wk, n = 8) undergoing unilateral sciatic neurectomy 8 wk before study were imaged with spatial volume resolution of 5.83 × 5.83 × 5.83 μm3 by SRμCT (20 keV) at the synchrotron radiation facility (SPring-8). Reconstructed image data were translated into local mineral densities by using a calibrated linear relationship between linear absorption coefficients and concentrations of homogeneous K2HPO4 solution. Pure bone three-dimensional images, produced by simple thresholding at a bone mineral density of 0.82 g/cm3, were analyzed for macro- and microscopic structural properties. In neurectomized hindlimbs, cortical canal network rarefaction as well as bone atrophy were found. The former was characterized by 30% smaller porosity, 11% smaller canal density in transverse section, and 38% smaller canal connectivity density than those in contralateral bone. On the other hand, no difference was found in bone mineral density between neurectomized and intact hindlimbs (1.37 vs. 1.36 g/cm3). In conclusion, SRμCT is a promising method for the three-dimensional analysis of cortical microstructure and the degree of mineralization in small animals.