• 생체재료학회지
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• 제22권4호
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• pp.279-289
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• 2018

Background: Cell behavior is the key to tissue regeneration. Given the fact that most of the cells used in tissue engineering are anchorage-dependent, their behavior including adhesion, growth, migration, matrix synthesis, and differentiation is related to the design of the scaffolds. Thus, characterization of the scaffolds is highly required. Micro-computed tomography (micro-CT) provides a powerful platform to analyze, visualize, and explore any portion of interest in the scaffold in a 3D fashion without cutting or destroying it with the benefit of almost no sample preparation need. Main body: This review highlights the relationship between the scaffold microstructure and cell behavior, and provides the basics of the micro-CT method. In this work, we also analyzed the original papers that were published in 2016 through a systematic search to address the need for specific improvements in the methods section of the papers including the amount of provided information from the obtained results. Conclusion: Micro-CT offers a unique microstructural analysis of biomaterials, notwithstanding the associated challenges and limitations. Future studies that will include micro-CT characterization of scaffolds should report the important details of the method, and the derived quantitative and qualitative information can be maximized.

• 한국정밀공학회지
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• 제24권1호
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• pp.110-117
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• 2007

This study investigated changes of mechanical characteristics of the trabecular and cortical bone in the lumbar vertebrae of the ovariectomised (OVX) rat. In previous researches, there were many studies for morphology of osteoporotic bones based on Micro-Computed Tomography (Micro-CT). However, there were few studies for detecting and tracking changes of mechanical characteristics of the trabecular and cortical bone in the lumbar vertebrae of the OVX rat. For this study, the 4th lumbar of the OVX rat (female Sprague-Dawley) was utilized as a specimen. An OVX rat was scanned at week 0 (just before surgery), at week 4, and week 8 after surgery. Micro-finite element (${\mu}-FE$) analysis was used to investigate mechanical characteristics of the trabecular and cortical bone in the lumbar vertebrae for an OVX rat. When the OVX rat (at week 8) was compared with the OVX rat (at week 0), the structural modulus of cortical and trabecualr bone was decreased by 52% and 99%, respectively. This study showed the change of mechanical characteristics of cortical bone as well as trabecular bone of an OVX rat. Detecting and tracking changes of mechanical characteristics could greatly contribute to an experiment test for the trabecular and cortical bone in the lumbar vertebrae of an OVX rat by using In-vivo Micro-CT.

• 한국가시화정보학회지
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• 제8권2호
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• pp.45-50
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• 2010

The objective of this study is to elucidate the feasibility of synchrotron X-ray micro CT as a non-destructive imaging method to visualize the three-dimensional morphological structures of biological and non-biological samples. The experiments were conducted in 7B2 X-ray micro CT beamline in Pohang Accelerate Laboratory (PAL). A rotational 3-axis stage was specially designed for $0^{\circ}-180^{\circ}$ scanning of test samples. Preliminary tests were performed for opaque samples including a mosquito head, a plant seed and gas diffusion layer (GDL) of polymer electrolyte fuel cell to verify the feasibility of the X-ray micro CT. It visualized clearly the internal structure of all the test samples, supporting its usefulness.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.1359-1360
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• 2010

• 한국지반공학회논문집
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• 제27권11호
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• pp.83-92
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• 2011

무질서하고 불균질한 형상을 갖는 지반 재료 내 간극 구조는 하중에 의한 재료의 변형 및 간극 내 유체의 흐름 등 물리 역학적 거동에 중요한 영향 인자이다. 최근 들어 X-ray CT에 의한 비파괴 검사를 통해 지반 재료의 내부 구조를 마이크로미터 단위의 높은 해상도를 통해 평가하는 기법이 사용되고 있다. CT 이미지는 재료의 많은 정보를 포함하고 있음에도 그에 따른 이미지 해석 기법의 개발이 다소 미흡하여 2, 3차원 이미지의 정성적 관찰 및 간극비와 같은 거시적인 물성치 획득만이 이루어지고 있다. 본 연구에서는 연속적으로 획득된 글라스 비드의 2차원 CT 이미지에 기반하여 3차원 입자 및 간극 구조를 형성하고, 복잡한 간극구조를 간극셀과 간극채널로 정량적 분리를 실시하였다. 이를 위해 좌표 변환법, 이진화, 들로네 삼각망, 그리고 유클리디안 거리변환법과 같은 이미지 프로세싱 기법을 3차원 CT 이미지에 적용하였고 불균질한 글라스 비드의 간극구조에 대해 정량적으로 간극셀의 분포 및 간극간의 연결도 평가가 가능함을 확인하였다.

• 치위생과학회지
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• 제23권1호
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• pp.60-67
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• 2023

Background: In our study, a silver diamine fluoride (SDF) compound for the treatment of dental caries was synthesized to characterize its remineralization activity upon direct application to deciduous teeth. This study aimed to use microscopic computed tomography (microCT) and nanoindentation to evaluate whether SDF composite application could effectively arrest dental caries in five exfoliated primary molars. Methods: Carious teeth were extracted and visually examined using quantitative photofluorescence devices (Qraycam and QraypenTM). After performing microCT, the SDF composite was applied to the teeth according to the manufacturer's instructions. The researchers exchanged and precipitated the irritant saliva once daily for 1 week. The teeth were sectioned longitudinally through the centers of the mesial and distal surfaces, embedded, polished, and measured using nanoindentation. Thereafter, microCT was repeated. Statistical analyses were performed using GraphPad Prism software. Results: Following SDF composite application, a remineralized layer was observed on microCT images, and the hardness increased when measured using nanoindentation. We found that demineralized enamel presented with an increased number of irregular crystals in the deep carious lesion group compared with those in the shallow carious lesion group, resulting in a rougher surface. Conclusion: The SDF composite may be used for remineralization of early caries and cessation of advanced caries in primary molars.

• Biomolecules & Therapeutics
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• 제23권2호
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• pp.195-200
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• 2015

We tested the hypothesis that micro-computed tomography (micro-CT) analysis provides a better quantitative readout of the therapeutic potential of methotrexate (MTX) for treating collagen-induced arthritis (CIA) in rats and compared to conventional histopathological examination. Rats were divided into three groups: Group 1 (G1) was treated with 0.9% saline, whereas groups 2 (G2) and 3 (G3) were boosted with type II collagen at days 0 and 7. Following the first collagen immunization, rats in G1 and G2 were treated with 0.9% saline and those in G3 were treated with 1.5 mg/kg MTX from day 14 to 28. All rats were sacrificed on day 28, at which point and all hind knee joints were analyzed by micro-CT and histopathological examination. Micro-CT analyses showed that bone volume and trabecular number were significantly decreased in G2 and G3 compared to G1 (p<0.01), as was percent bone volume (p<0.05 and p<0.01, respectively). However, bone surface/bone volume was significantly increased in G2 and G3 compared to G1 (p<0.05 and p<0.01, respectively). Trabecular separation was significantly increased in G3 compared to G1 (p<0.05). Histopathological examination showed that knee joints of rats in G2 and G3 showed severe joint destruction with inflammatory cell infiltration. However, cartilage destruction was slightly reduced in G3 compared to G2. Taken together, these results suggest that MTX treatment reduced cartilage destruction in rats with CIA, and micro-CT analyses made it possible to quantify arthritic bony lesion.

• 한국치위생학회지
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• 제10권5호
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• pp.947-953
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• 2010

Objectives : The purpose of this investigation was to evaluate the remineralization and acid resistance in fluoride varnish by Micro-computed tomography (micro CT). Methods : Specimens of bovine teeth enamel were embedded in resin, polished and randomly divided into 3 groups (a control group, a NaF solution group, a fluoride varnish group). Each group has 3 specimens that was standardized according to Vickers hardness number (VHN). Specimens were immersed in demineralization solution for 72 hours. The control group had no treatment, the NaF solution group was treated by a 5% NaF solution for 4 minutes, and the fluoride varnish group was treated by a fluoride varnish for one hour. All specimens were subjected to a chemical pH cycling method for 14 days. After a chemical pH cycling method, the density were measured using micro CT. Then, specimens were immersed in each demineralization solution for 72 hours. After demineralization processed, the density were measured using micro CT. Results : 1. The density was significantly higher in the fluoride varnish and 5% NaF solution group than that of the control group after 14 days cycling (p<0.05). And the density value of the fluoride varnish group was higher than that of the 5% NaF solution, with no significant difference. 2. The differences of density after acid resistance treatment were statistically significant among 3 groups(p<0.05). Conclusions : It is suggested that fluoride varnish showed the remineralizing effect and acid resistance effect on the enamel, and micro CT could be used to evaluate the change of enamel lesion.

• 대한치과보철학회지
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• 제52권4호
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• pp.298-304
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• 2014

목적: 본 선행 연구는 recombinant human transforming growth factor-${\beta}2$ (rhTGF-${\beta}2$)/ poly lactic-co-glycolic acid (PLGA) 복합체를 타이타늄 임플란트에 처리하였을 때 골 유착에 미치는 영향을 알아보기 위해 시행된 것으로 토끼 모델을 사용하였다. 재료 및 방법: 8개의 임플란트를 300V에서 3분 동안 양극 산화하였다. 그 중 4개는 electrospray법으로 rhTGF-${\beta}2$/PLGA를 코팅하여 실험군으로 설정하였다. 4마리의 New Zealand rabbit의 tibiae에 1개씩의 실험군과 대조군 임플란트를 식립하였으며, 3주와 6주에 2마리씩 희생하여 micro-computed tomography(microCT) 촬영 후 분석하였다. 결과: Scanning electron microscope (SEM) 사진에서 rhTGF-${\beta}2$/PLGA 입자가 임플란트 표면에 균일하게 분산되어 있음을 확인하였다. MicroCT 분석 결과 통계적으로 유의하지는 않지만 rhTGF-${\beta}2$/PLGA를 처리한 임플란트가 bone volume/total volume (BV/TV)와 trabecular thickness (Tb.Th) 값이 더 높은 경향성을 보였으며, cross sectional view에서 더 많은 골이 형성되었음을 확인하였다. 결론: rhTGF-${\beta}2$/PLGA 표면처리된 임플란트가 주변 골의 양적 성장을 촉진시킬 수 있으며 임플란트 초기 골 유착을 증진시킬 수 있는 가능성을 보였다.

• Imaging Science in Dentistry
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• 제38권1호
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• pp.29-37
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• 2008

Purpose: The aim of this study was to observe the bony change in the OVX rat longitudinally and to study the alendronate effect. Materials and Methods: Eighteen Sprague-Dewley rats, eight-week old each, were randomly assigned into three groups: one of those sham-operated (N=4), the other two were OVX: saline-treated (N=7) and alendronate-treated group (N=7). The saline-treated group was administered with saline solution (0.1mL/100g) daily, while the alendronate-treated group was given alendronate (1mg/kg, Sigma-Aldrich Corp. Korea) daily. Micro-CT scannings of the lumbar were consecutively done at baseline, at 3-week intervals during 9 weeks. Two and three dimensional bony analysis were done. Bone mineral density (BMD) was measured with Piximus (GE Lunar Co. USA). The average values of these three methods were compared with each group. Results: After 6 weeks the BMD of the OVX group showed lower tendency than that of sham group. After 6 weeks many 3D parameters of micro-CT showed higher values in the OVX-alendronate group compared with the OVXsaline group. Most 2D bony parameters were higher in the OVX-alendronate group compared with the OVX-saline group at 9 weeks. Conclusion: This study showed low BMD of the OVX group after 6 weeks and showed the effect of alendronate on the BMD and bony structures of ovariectomized rats. This study also showed usefulness of in vivo micro-CT in monitoring individual bone changes over time.