scholarly journals Effect of micro-computed tomography reconstruction protocols on bone fractal dimension analysis

2019 ◽  
Vol 48 (8) ◽  
pp. 20190235
Author(s):  
Hugo Gaêta-Araujo ◽  
Nicolly Oliveira-Santos ◽  
Danieli Moura Brasil ◽  
Eduarda Helena Leandro do Nascimento ◽  
Daniela Verardi Madlum ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Trabecular Bone ◽  
Micro Ct ◽  
Ct Reconstruction ◽  
Micro Computed Tomography ◽  
Beam Hardening ◽  
Scan Time ◽  
Beam Hardening Correction ◽  
Box Counting Method ◽  
Artefact Correction

Objectives: To evaluate the influence of the level of three micro-CT reconstruction tools: beam-hardening correction (BHC), smoothing filter (SF), and ring artefact correction (RAC) on the fractal dimension (FD) analysis of trabecular bone. Methods: Five Wistar rats’ maxillae were individually scanned in a SkyScan 1174 micro-CT device, under the following settings: 50 kV, 800 µA, 10.2 µm voxel size, 0.5 mm Al filter, rotation step 0.5°, two frames average, 180° rotation and scan time of 35 min. The raw images were reconstructed under the standard protocol (SP) recommended by the manufacturer, a protocol without any artefact correction tools (P0) and 35 additional protocols with different combinations of SF, RAC and BHC levels. The same volume of interest was established in all reconstructions for each maxilla and the FD was calculated using the Kolmogorov (box counting) method. One-way ANOVA with Dunnet’s post-hoc test was used to compare the FD of each reconstruction protocol (P0–P35) with the SP (α = 5%). Multiple linear regression verified the dependency of reconstruction tools in FD. Results: Overall, FD values are not dependent on RAC (p = 0.965), but increased significantly when the level of BHC and SF increased (p < 0.001). FD values from protocols with BHC at 45% combined with SF of 2, and BHC at 30% combined with SF of 4 or 6 had no statistical difference compared to SP. Conclusions: BHC and SF tools affect the FD values of micro-CT images of the trabecular bone. Therefore, these reconstruction parameters should be standardized when the FD is analyzed.

scholarly journals Using micro-computed tomography to reveal the anatomy of adult Diaphorina citri Kuwayama (Insecta: Hemiptera, Liviidae) and how it pierces and feeds within a citrus leaf

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Javier Alba-Tercedor ◽  
Wayne B. Hunter ◽  
Ignacio Alba-Alejandre
Keyword(s):  
Computed Tomography ◽  
Significant Advance ◽  
Micro Ct ◽  
Diaphorina Citri ◽  
Ct Reconstruction ◽  
Internal Anatomy ◽  
Micro Computed Tomography ◽  
Citrus Leaf ◽  
Teaching Aids ◽  
Adult Feeding

AbstractThe Asian citrus psyllid (ACP), Diaphorina citri, is a harmful pest of citrus trees that transmits Candidatus Liberibacter spp. which causes Huanglongbing (HLB) (citrus greening disease); this is considered to be the most serious bacterial disease of citrus plants. Here we detail an anatomical study of the external and internal anatomy (excluding the reproductive system) using micro-computed tomography (micro-CT). This is the first complete 3D micro-CT reconstruction of the anatomy of a psylloid insect and includes a 3D reconstruction of an adult feeding on a citrus leaf that can be used on mobile devices. Detailed rendered images and videos support first descriptions of coxal and scapus antennal glands and sexual differences in the internal anatomy (hindgut rectum, mesothoracic ganglion and brain). This represents a significant advance in our knowledge of ACP anatomy, and of psyllids in general. Together the images, videos and 3D model constitute a unique anatomical atlas and are useful tools for future research and as teaching aids.

Beam hardening correction for sparse-view CT reconstruction

2015 ◽  
Author(s):  
Wenlei Liu ◽  
Junyan Rong ◽  
Peng Gao ◽  
Qimei Liao ◽  
HongBing Lu
Keyword(s):  
Ct Reconstruction ◽  
Beam Hardening ◽  
Beam Hardening Correction

scholarly journals Spatial Correlations of Trabecular Bone Microdamage with Local Stresses and Strains Using Rigid Image Registration

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
Srinidhi Nagaraja ◽  
Oskar Skrinjar ◽  
Robert E. Guldberg
Keyword(s):  
Finite Element ◽  
Image Registration ◽  
Trabecular Bone ◽  
Tissue Level ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Element Analysis ◽  
Registration Algorithm ◽  
Local Bone ◽  
Local Stresses

Although microdamage is known to accumulate in trabecular bone with overloading and aging, the tissue-level stresses and strains associated with local bone failure are not well known. Local correlation of microdamage with microstructural stresses and strains requires methods to accurately register histological sections with micro-computed tomography (micro-CT) based finite element models. In addition, the resolution of correlation (i.e., grid size) selected for analysis may affect the observed results. Therefore, an automated, repeatable, and accurate image registration algorithm was developed to determine the range of local stresses and strains associated with microdamage initiation. Using a two-dimensional rigid registration algorithm, bone structures from histology and micro-CT imaging were aligned. Once aligned, microdamaged regions were spatially correlated with local stresses and strains obtained from micro-CT based finite element analysis. Using this more sophisticated registration technique, we were able to analyze the effects of varying spatial grid resolution on local stresses and strains initiating microdamage. The results indicated that grid refinement to the individual pixel level (pixel-by-pixel method) more precisely defined the range of microdamage initiation compared to manually selected individual damaged and undamaged trabeculae. Using the pixel-by-pixel method, we confirmed that trabecular bone from younger cows sustained higher local strains prior to microdamage initiation compared to older bone.

Characterization of Human Cortical and Trabecular Bone Structural Change by NMR and Micro-CT

2012 ◽  
Author(s):  
Qingwen Ni ◽  
Todd Bredbenner
Keyword(s):  
Trabecular Bone ◽  
Spin Relaxation ◽  
Structural Changes ◽  
Relaxation Times ◽  
Proton Nuclear Magnetic Resonance ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
T2 Relaxation ◽  
Ct Measurement

The techniques of low-field pulsed proton nuclear magnetic resonance (NMR) spin relaxation and Micro-CT are described for assessment of structural changes of human cortical and trabecular bone in vitro. The technique involves spin-spin relaxation measurement and inversion spin-spin spectral analysis methods for NMR. From NMR measurement, the CPMG T2 relaxation data can be inverted to T2 relaxation distribution and this distribution then can be transformed to a pore size distribution with the longer relaxation times corresponding to larger pores. In Micro-CT measurement, each trabecular bone specimen was individually scanned using a micro-computed tomography (micro-CT) system and 12 micron dimensionally-isotropic voxels were reconstructed. Due to the resolution limitation, Micro-CT measurement on cortical bone was not success, however, NMR measurement was success for both cortical and trabecular bones.

scholarly journals FRACTAL ANALYSIS OF TRABECULAR BONE: A STANDARDISED METHODOLOGY

2011 ◽  
Vol 19 (1) ◽  
pp. 45 ◽  
Author(s):  
Ian Parkinson ◽  
Nick Fazzalari
Keyword(s):  
Fractal Dimension ◽  
Trabecular Bone ◽  
Fractal Analysis ◽  
Fractal Dimensions ◽  
Box Counting ◽  
Cell Tissue ◽  
Image Analyser ◽  
Model Independent ◽  
Box Counting Method ◽  
Image Orientation

A standardised methodology for the fractal analysis of histological sections of trabecular bone has been established. A modified box counting method has been developed for use on a PC based image analyser (Quantimet 500MC, Leica Cambridge). The effect of image analyser settings, magnification, image orientation and threshold levels, was determined. Also, the range of scale over which trabecular bone is effectively fractal was determined and a method formulated to objectively calculate more than one fractal dimension from the modified Richardson plot. The results show that magnification, image orientation and threshold settings have little effect on the estimate of fractal dimension. Trabecular bone has a lower limit below which it is not fractal (λ<25 μm) and the upper limit is 4250 μm. There are three distinct fractal dimensions for trabecular bone (sectional fractals), with magnitudes greater than 1.0 and less than 2.0. It has been shown that trabecular bone is effectively fractal over a defined range of scale. Also, within this range, there is more than 1 fractal dimension, describing spatial structural entities. Fractal analysis is a model independent method for describing a complex multifaceted structure, which can be adapted for the study of other biological systems. This may be at the cell, tissue or organ level and compliments conventional histomorphometric and stereological techniques.

Contribution of Three-Dimensional Trabecular Bone Microstructure of the Proximal Femur to its Mechanical Properties as Assessed by Micro-Finite Element Analysis

2006 ◽  
Vol 321-323 ◽  
pp. 278-281
Author(s):  
Wen Quan Cui ◽  
Ye Yeon Won ◽  
Myong Hyun Baek ◽  
Kwang Kyun Kim
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Trabecular Bone ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Bone Microarchitecture ◽  
Element Model ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Element Analysis

The purpose of this study was to investigate the contribution of the microstructural properties of trabecular bone in predicting its elastic modulus in the intertrochanteric region. A total of 15 trabecular bone core specimens were obtained from the proximal femurs of patients undergoing total hip arthroplasty. The micro-computed tomography (micro-CT) was used to scan each specimen to obtain micro-morphology. Microstructural parameters were directly calculated using software. Micro-CT images were converted to micro-finite element model using meshing technique, and then micro-finite element analysis (FEA) was performed to assess the mechanical property (Young’s modulus) of trabecular bone. The results showed that the ability to explain this variance of Young’s modulus is improved by combining the structural indices with each other. It suggested that assessment of bone microarchitecture should be added as regards detection of osteoporosis and evaluation of the efficacy of drug treatments for osteoporosis.

Sign in / Sign up

Export Citation Format

Share Document