scholarly journals Imaging Techniques for the Assessment of the Bone Osteoporosis-Induced Variations with Particular Focus on Micro-CT Potential

2020 ◽  
Vol 10 (24) ◽  
pp. 8939
Author(s):  
Giulia Molino ◽  
Giorgia Montalbano ◽  
Carlotta Pontremoli ◽  
Sonia Fiorilli ◽  
Chiara Vitale-Brovarone
Keyword(s):  
Fracture Risk ◽  
Imaging Techniques ◽  
Image Resolution ◽  
Osteoporotic Bone ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Mineral Density ◽  
Gold Standard Method ◽  
Long Time ◽  
Technological Improvements

For long time, osteoporosis (OP) was exclusively associated with an overall bone mass reduction, leading to lower bone strength and to a higher fracture risk. For this reason, the measurement of bone mineral density through dual X-ray absorptiometry was considered the gold standard method for its diagnosis. However, recent findings suggest that OP causes a more complex set of bone alterations, involving both its microstructure and composition. This review aims to provide an overview of the most evident osteoporosis-induced alterations of bone quality and a résumé of the most common imaging techniques used for their assessment, at both the clinical and the laboratory scale. A particular focus is dedicated to the micro-computed tomography (micro-CT) due to its superior image resolution, allowing the execution of more accurate morphometric analyses, better highlighting the architectural alterations of the osteoporotic bone. In addition, micro-CT has the potential to perform densitometric measurements and finite element method analyses at the microscale, representing potential tools for OP diagnosis and for fracture risk prediction. Unfortunately, technological improvements are still necessary to reduce the radiation dose and the scanning duration, parameters that currently limit the application of micro-CT in clinics for OP diagnosis, despite its revolutionary potential.

Hypophosphatasia: Evaluation of Size and Mineral Density of Exfoliated Teeth

2016 ◽  
Vol 40 (6) ◽  
pp. 496-502 ◽  
Author(s):  
S Hayashi-Sakai ◽  
N Numa-Kinjoh ◽  
M Sakamoto ◽  
J Sakai ◽  
J Matsuyama ◽  
...  
Keyword(s):  
Density Distribution ◽  
Primary Teeth ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Mineral Density ◽  
Normal Range ◽  
Mean Values ◽  
Present Patient ◽  
Ct Analysis ◽  
The Mean

Objective: Most cases of hypophosphatasia (HPP) exhibit early loss of primary teeth. Results of micro-computed tomography (micro-CT) analysis of teeth with HPP have not yet been reported. The purpose of the present study was to describe the size and mineral density distribution and mapping of exfoliated teeth with HPP using micro CT. Study design: Seven exfoliated teeth were obtained from a patient with HPP. Exfoliated teeth sizes were measured on micro CT images and mineral densities of the mandibular primary central incisors were determined. Results: Partial dentures were fabricated for the patient to replace the eight primary teeth which had exfoliated. Most primary teeth sizes were within the normal range. The mean values of enamel and dentin mineral densities in teeth with HPP were 1.35 and 0.88 g/cm3, respectively, in the mandibular primary central incisors. Conclusion: Mineral density distribution and mapping revealed that the values in teeth with HPP were lower than the homonymous teeth controls in all regions from the crown to apex. Furthermore, it was demonstrated that the differences between HPP and controls were larger on the crown side and the differences tended to converge on the apex side. These results suggested that the present patient showed mild hypomineralization in the primary dentition.

scholarly journals Experimental study of the effects of hypoxia simulator on osteointegration of titanium prosthesis in osteoporotic rats

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Jiangfeng Liu ◽  
Huijun Kang ◽  
Jiangfeng Lu ◽  
Yike Dai ◽  
Fei Wang
Keyword(s):  
Signaling Pathway ◽  
Control Group ◽  
Osteoporotic Bone ◽  
Sham Operation ◽  
Mrna Levels ◽  
Micro Ct ◽  
Sprague Dawley ◽  
Micro Computed Tomography ◽  
Sham Operation Group ◽  
Pull Out

Abstract Background Poor osseointegration is the key reason for implant failure after arthroplasty,whether under osteoporotic or normal bone conditions. To date, osseointegration remains a major challenge. Recent studies have shown that deferoxamine (DFO) can accelerate osteogenesis by activating the hypoxia signaling pathway. The purpose of this study was to test the following hypothesis: after knee replacement, intra-articular injection of DFO will promote osteogenesis and osseointegration with a 3D printed titanium prosthesis in the bones of osteoporotic rats. Materials and methods Ninety female Sprague–Dawley rats were used for the experiment. Ten rats were used to confirm the successful establishment of the osteoporosis model: five rats in the sham operation group and five rats in the ovariectomy group. After ovariectomy and knee arthroplasty were performed, the remaining 80 rats were randomly divided into DFO and control groups (n = 40 per group). The two groups were treated by intraarticular injection of DFO and saline respectively. After 2 weeks, polymerase chain reaction (PCR) and immunohistochemistry were used to evaluate the levels of HIF-1a, VEGF, and CD31. HIF-1a and VEGF have been shown to promote angiogenesis and bone regeneration, and CD31 is an important marker of angiogenesis. After 12 weeks, the specimens were examined by micro-computed tomography (micro-CT), biomechanics, and histopathology to evaluate osteogenesis and osseointegration. Results The results of PCR showed that the mRNA levels of VEGF and CD31 in the DFO group were significantly higher than those in the control group. The immunohistochemistry results indicated that positive cell expression of HIF-1a, VEGF, and CD31 in the DFO group was also higher. Compared with the control group, the micro-CT parameters of BMD, BV/TV, TB. N, and TB. Th were significantly higher. The maximal pull-out force and the bone-to-implant contact value were also higher. Conclusions The local administration of DFO, which is used to activate the HIF-1a signaling pathway, can promote osteogenesis and osseointegration with a prosthesis in osteoporotic bone.

scholarly journals Micro-CT for Biological and Biomedical Studies: A Comparison of Imaging Techniques

2021 ◽  
Vol 7 (9) ◽  
pp. 172
Author(s):  
Kleoniki Keklikoglou ◽  
Christos Arvanitidis ◽  
Georgios Chatzigeorgiou ◽  
Eva Chatzinikolaou ◽  
Efstratios Karagiannidis ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Imaging Techniques ◽  
Laser Scanning Microscopy ◽  
Three Dimensions ◽  
Morphological Data ◽  
Confocal Laser ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Non Destructive ◽  
Great Resolution

Several imaging techniques are used in biological and biomedical studies. Micro-computed tomography (micro-CT) is a non-destructive imaging technique that allows the rapid digitisation of internal and external structures of a sample in three dimensions and with great resolution. In this review, the strengths and weaknesses of some common imaging techniques applied in biological and biomedical fields, such as optical microscopy, confocal laser scanning microscopy, and scanning electron microscopy, are presented and compared with the micro-CT technique through five use cases. Finally, the ability of micro-CT to create non-destructively 3D anatomical and morphological data in sub-micron resolution and the necessity to develop complementary methods with other imaging techniques, in order to overcome limitations caused by each technique, is emphasised.

scholarly journals Feasibility of Application of the Newly Developed Nano-Biomaterial, β-TCP/PDLLA, in Maxillofacial Reconstructive Surgery: A Pilot Rat Study

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 303
Author(s):  
Erina Toda ◽  
Yunpeng Bai ◽  
Jingjing Sha ◽  
Quang Ngoc Dong ◽  
Huy Xuan Ngo ◽  
...  
Keyword(s):  
Bone Graft ◽  
Reconstructive Surgery ◽  
Leptin Receptor ◽  
Early Stage ◽  
Healing Process ◽  
Bone Defects ◽  
Micro Ct ◽  
Sprague Dawley ◽  
Micro Computed Tomography ◽  
Mineral Density

This study was performed to examine the applicability of the newly developed nano-biocomposite, β-tricalcium phosphate (β-TCP)/u-HA/poly-d/l-lactide (PDLLA), to bone defects in the oral and maxillofacial area. This novel nano-biocomposite showed several advantages, including biocompatibility, biodegradability, and osteoconductivity. In addition, its optimal plasticity also allowed its utilization in irregular critical bone defect reconstructive surgery. Here, three different nano-biomaterials, i.e., β-TCP/PDLLA, β-TCP, and PDLLA, were implanted into critical bone defects in the right lateral mandible of 10-week-old Sprague–Dawley (SD) rats as bone graft substitutes. Micro-computed tomography (Micro-CT) and immunohistochemical staining for the osteogenesis biomarkers, Runx2, osteocalcin, and the leptin receptor, were performed to investigate and compare bone regeneration between the groups. Although the micro-CT results showed the highest bone mineral density (BMD) and bone volume to total volume (BV/TV) with β-TCP, immunohistochemical analysis indicated better osteogenesis-promoting ability of β-TCP/PDLLA, especially at an early stage of the bone healing process. These results confirmed that the novel nano-biocomposite, β-TCP/PDLLA, which has excellent biocompatibility, bioresorbability and bioactive/osteoconductivity, has the potential to become a next-generation biomaterial for use as a bone graft substitute in maxillofacial reconstructive surgery.

scholarly journals Automated segmentation of the lamina cribrosa using Frangi's filter: a novel approach for rapid identification of tissue volume fraction and beam orientation in a trabeculated structure in the eye

2015 ◽  
Vol 12 (104) ◽  
pp. 20141009 ◽  
Author(s):  
Ian C. Campbell ◽  
Baptiste Coudrillier ◽  
Johanne Mensah ◽  
Richard L. Abel ◽  
C. Ross Ethier
Keyword(s):  
Connective Tissue ◽  
Volume Fraction ◽  
Second Harmonic ◽  
Imaging Techniques ◽  
Lamina Cribrosa ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Tissue Volume

The lamina cribrosa (LC) is a tissue in the posterior eye with a complex trabecular microstructure. This tissue is of great research interest, as it is likely the initial site of retinal ganglion cell axonal damage in glaucoma. Unfortunately, the LC is difficult to access experimentally, and thus imaging techniques in tandem with image processing have emerged as powerful tools to study the microstructure and biomechanics of this tissue. Here, we present a staining approach to enhance the contrast of the microstructure in micro-computed tomography (micro-CT) imaging as well as a comparison between tissues imaged with micro-CT and second harmonic generation (SHG) microscopy. We then apply a modified version of Frangi's vesselness filter to automatically segment the connective tissue beams of the LC and determine the orientation of each beam. This approach successfully segmented the beams of a porcine optic nerve head from micro-CT in three dimensions and SHG microscopy in two dimensions. As an application of this filter, we present finite-element modelling of the posterior eye that suggests that connective tissue volume fraction is the major driving factor of LC biomechanics. We conclude that segmentation with Frangi's filter is a powerful tool for future image-driven studies of LC biomechanics.

scholarly journals Assessment of single and double coronary bifurcation stenting techniques using multimodal imaging and 3D modeling in reanimated swine hearts using Visible Heart® methodologies

2021 ◽  
Author(s):  
Thomas F. Valenzuela ◽  
Francesco Burzotta ◽  
Tinen L. Iles ◽  
Jens F. Lassen ◽  
Paul A. Iaizzo
Keyword(s):  
3D Modeling ◽  
Multimodal Imaging ◽  
Computational Models ◽  
Imaging Techniques ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Coronary Bifurcation ◽  
Post Intervention ◽  
Bifurcation Stenting ◽  
Wall Interactions

AbstractStent implantation in bifurcated coronary lesions is technically challenging so that procedural refinements are continuously investigated. Novel procedure modeling and intracoronary imaging techniques may offer critical insights on stent deformations and stent-wall interactions during bifurcation stenting procedures. Thus, we assessed coronary bifurcation stenting techniques using multimodal imaging and 3D modeling in reanimated swine hearts. Harvested swine hearts were reanimated using Visible Heart® methodologies and (under standard fluoroscopic guidance) used to test 1-stent (provisional and inverted provisional) and 2-stent (culotte, TAP and DK-crush) techniques on bifurcations within various coronary vessels using commercially available devices. Intracoronary angioscopy and frequency-domain optical-coherence-tomography (OCT) were obtained during the procedures. 3D OCT reconstruction and micro-computed tomography 3D modeling (post heart fixations) were used to assess stent deformations and stent-wall interactions. We conducted multiple stenting procedures and collected unique endoscopic and OCT images (and subsequent computational models from micro-CT) to assess stent deformations and device/wall interactions during different steps of bifurcation stenting procedures. Endoscopy, micro-CT and virtual reality processing documented that different 1- and 2-stent techniques, practiced according to experts’ recommended steps, achieve optimal post-intervention stent conformation. As compared with intra-procedural endoscopy, software-generated 3D OCT images accurately depicted stent deformations during 1-stent techniques. On the opposite, during more complex 2-stent techniques, some defects were appreciated at 3D OCT reconstruction despite optimal 2D OCT images. This study provided unique insights regarding both stent deformations occurring in the course of bifurcation stenting and the efficacy of OCT to visualize them.

scholarly journals The effects of 8DSS peptide on remineralization in a rat model of enamel caries evaluated by two nondestructive techniques

2019 ◽  
Vol 17 (1) ◽  
pp. 228080001982779 ◽  
Author(s):  
Wenyue Zheng ◽  
Longjiang Ding ◽  
Yufei Wang ◽  
Sili Han ◽  
Sainan Zheng ◽  
...  
Keyword(s):  
Dental Caries ◽  
Early Stage ◽  
Repetitive Sequences ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Mineral Density ◽  
Enamel Caries ◽  
Carious Lesions ◽  
Caries Model

Nowadays, dental caries is one of the most common oral health problems, affecting most individuals. It has been found that, by remineralizing enamel at an early stage in the formation of enamel caries, teeth can be effectively protected from dental caries. In this work, a peptide with eight repetitive sequences of aspartate-serine-serine (8DSS) is applied as the bio-mineralizer in an in-vivo rat enamel caries model. Nondestructive quantitative light-induced fluorescence-digital (QLF-D) imaging and micro-computed tomography (micro-CT) are used to evaluate the remineralization of enamel carious lesions by measuring the total fluorescence radiance loss of the molar area (Δ QTotal), acquired using QLF-D imaging, and the mineral density and residual molar enamel volume, acquired using micro-CT. Correlations are explored between Δ QTotal and mineral density (strong correlation, r = 0.8000, p < 0.001) and Δ QTotal and residual molar enamel volume (moderate correlation, r = 0.6375, p < 0.001). Our results demonstrate that 8DSS is a promising in-vivo remineralization agent that exhibits comparable effects to NaF ( p < 0.05), which has been verified using the classical Keyes method. Moreover, the nondestructive QLF-D and micro-CT methods can be combined to quantify the remineralization of enamel carious lesions three-dimensionally in vivo, making them broadly applicable in quantifying hard tissues.

Diagnostic Yield of Micro-Computed Tomography (micro-CT) Versus Histopathology of a Canine Oral Fibrosarcoma

2020 ◽  
Vol 37 (1) ◽  
pp. 14-21
Author(s):  
Matthias C. Eberspächer-Schweda ◽  
Kira Schmitt ◽  
Stephan Handschuh ◽  
Andrea Fuchs-Baumgartinger ◽  
Alexander M. Reiter
Keyword(s):  
Computed Tomography ◽  
Contrast Agent ◽  
Tumor Volume ◽  
Ct Imaging ◽  
Image Resolution ◽  
Surrounding Tissue ◽  
Histopathological Diagnosis ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Tumor Margins

Micro-computed tomography (micro-CT) imaging currently gains increased interest in human as well as veterinary medicine. The ability to image 3-dimensional (3D) biopsy specimens nondestructively down to 1 µm spatial resolution makes it a promising tool for microscopic tissue evaluation in addition to histopathology. Visualizing tumor margins and calculating tumor load on 3D reconstructions may also enhance oncological therapies. The objective of this study was to describe the workflow from tumor resection to histopathological diagnosis, using both routine hematoxylin-eosin (HE)-stained sections and micro-CT tomograms on a stage II oral fibrosarcoma in a 7-year-old Hovawart dog. The maxillectomy specimen was fixed with formalin and stained with an X-ray dense soft tissue contrast agent. Micro-CT imaging was done using an ex vivo specimen micro-CT device. Tumor margins could not be exactly determined on micro-CT tomograms due to limited image resolution and contrast. Histopathology was performed after washing out the contrast agent. It showed neoplastic cells infiltrating the surrounding tissue further than assumed from micro-CT images. A total tumor volume of 10.3 cm3 could be calculated based on correlating micro-CT tomograms with HE-stained sections. This correlative approach may be of particular interest for oncological therapy. More than that, micro-CT imaging technology supported histopathology by means of 3D orientation and selection of slices to be cut on determining tumor margins. In this clinical case report, micro-CT imaging did not provide unambiguous clinical evidence for oncological decision-making, but it showed potential to support histopathology and calculate tumor volume for further clinical use.

VALIDATION OF A BONE MINERAL DENSITY CALIBRATION PROTOCOL FOR MICRO-COMPUTED TOMOGRAPHY

2017 ◽  
Vol 17 (01) ◽  
pp. 1750015
Author(s):  
FABIO BARUFFALDI ◽  
ROSSELLA STOICO ◽  
SIMONE TASSANI ◽  
LAURA MECOZZI ◽  
STEFANO FALCIONI ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Bone Mineral Density ◽  
Trabecular Bone ◽  
Bone Mineral ◽  
Bone Structure ◽  
Tissue Type ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Mineral Density ◽  
Calibration Protocol

Micro-computed tomography (micro-CT) is widely used for in vitro studies to characterize bone structure at the resolution of 10–100 microns. However, a densitometric calibration protocol is necessary to convert the X-ray attenuation coefficient provided by micro-CT in bone mineral density (BMD). The lastest one has an important role to improve the accuracy of subject-specific finite element models. This work presents a simple calibration protocol based on the use of solid hydroxyapatite phantoms with the correction of the beam hardening effect. The method was validated in comparison to ashing measures of cortical and trabecular human bone. In addition, bone samples tissue mineral density (TMD) was calculated with two different methods. The correlation between ash density and BMD was linear both for cortical ([Formula: see text]) and trabecular bone ([Formula: see text]). The analysis stratified by tissue type versus the pooled analysis confirmed the validity of a common linear model for both types of tissue ([Formula: see text]). Despite its simplicity, the correlation obtained in this work does not depend on the acquisition settings of the micro-CT. TMD was shown to be dependent on the tissue investigated, with values in the range of 1.15–1.21[Formula: see text]mg/mm3 for trabecular bone, and 1.19–1.29[Formula: see text]mg/mm3 for cortical bone. Results are of some interest for generating micro finite elements models.

scholarly journals Experimental arthritis and Porphyromonas gingivalis administration synergistically decrease bone regeneration in femoral cortical defects

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Go Okumura ◽  
Naoki Kondo ◽  
Keisuke Sato ◽  
Kazuhisa Yamazaki ◽  
Hayato Ohshima ◽  
...  
Keyword(s):  
Risk Factors ◽  
Bone Mineral Density ◽  
Bone Regeneration ◽  
Porphyromonas Gingivalis ◽  
Bone Mineral ◽  
Micro Ct ◽  
Bone Area ◽  
Micro Computed Tomography ◽  
Mineral Density ◽  
Osteoclast Number

AbstractPorphyromonas gingivalis infection can lead to periodontitis and dysbiosis, which are known risk factors for rheumatoid arthritis (RA). We investigated whether P. gingivalis administration affected bone regeneration in mice with or without arthritis. We administered P. gingivalis to male DBA/1 J mice that were or were not sensitised to type II collagen-induced arthritis (CIA). All mice underwent drilling of bilateral femurs. We histologically evaluated new bone regeneration (bone volume of the defect [BVd]/tissue volume of the defect [TVd]) using micro-computed tomography (micro-CT), osteoclast number/bone area, and active osteoblast surface/bone surface (Ob.S/BS). We measured serum cytokine levels and bone mineral density of the proximal tibia using micro-CT. CIA resulted in significantly reduced bone regeneration (BVd/TVd) at all time-points, whereas P. gingivalis administration showed similar effects at 2 weeks postoperatively. CIA resulted in higher osteoclast number/bone area and lower Ob.S/BS at 2 and 3 weeks postoperatively, respectively. However, P. gingivalis administration resulted in lower Ob.S/BS only at 2 weeks postoperatively. During later-stage bone regeneration, CIA and P. gingivalis administration synergistically decreased BVd/TVd, increased serum tumour necrosis factor-α, and resulted in the lowest bone mineral density. Therefore, RA and dysbiosis could be risk factors for prolonged fracture healing.

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