• Journal of International Society for Simulation Surgery
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• v.3 no.1
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• pp.36-38
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• 2016

Fibrous dysplasia is a relatively rare disease but the management would be quite challenging. Because this is not a malignant tumor, the preservation of the facial contour and the various functions seems to be important in treatment planning. Until now the facial bone reconstruction with autogenous bone would be the standard. Although the autogenous bone would be the ideal one for facial bone reconstruction, donor site morbidity would be the inevitable problem in many cases. Meanwhile, various types of allogenic and alloplastic materials have been also used. However, facial bone reconstruction with many alloplastic material have produced no less complications including infection, exposure, and delayed wound healing. Because the 3D printing technique evolved so fast that 3D printed titanium implant were possible recently. The aim of this trial is to try to restore the original maxillary anatomy as possible using the 3D printing model, based on the mirrored three dimensional CT images based on the computer simulation. Preoperative computed tomography (CT) data were processed for the patient and a rapid prototyping (RP) model was produced. At the same time, the uninjured side was mirrored and superimposed onto the traumatized side, to create a mirror-image of the RP model. And we molded Titanium mesh to reconstruct three-dimensional maxillary structure during the operation. This prefabricated Titanium-mesh implant was then inserted onto the defected maxilla and fixed. Three dimensional printing technique of titanium material based on the computer simulation turned out to be successful in this patient. Individualized approach for each patient could be an ideal way to restore the facial bone.

• Journal of International Society for Simulation Surgery
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• v.1 no.2
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• pp.99-102
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• 2014

The skull defect can be made after the trauma, oncologic problems or neurosurgery. The skull reconstruction has been the challenging issue in craniofacial fields for a long time. So far the skull reconstruction with autogenous bone would be the standard. Although the autogenous bone would be the ideal one for skull reconstruction, donor site morbidity would be the inevitable problem in many cases. Meanwhile various types of allogenic and alloplastic materials have been also used. However, skull reconstruction with many alloplastic material have produced no less complications including infection, exposure, and delayed wound healing. Because the 3D printing technique evolved so fast that 3D printed titanium implant were possible recently. The aim of this trial is to try to restore the original skull anatomy as possible using the 3D printed titanium implant, based on the mirrored three dimensional CT images based on the computer simulation. Preoperative computed tomography (CT) data were processed for the patient and a rapid prototyping (RP) model was produced. At the same time, the uninjured side was mirrored and superimposed onto the traumatized side, to create a mirror-image of the RP model. And we fabricated Titanium implant to reconstruct three-dimensional orbital structure in advance, using the 3D printer. This prefabricated Titanium-implant was then inserted onto the defected skull and fixed. Three dimensional printing technique of titanium material based on the computer simulation turned out to be very successful in this patient. Individualized approach for each patient could be an ideal way to manage the traumatic patients in near future.

• Imaging Science in Dentistry
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• v.34 no.3
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• pp.151-157
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• 2004

Purpose : To evaluate the quantitative accuracy of three-dimensional (3D) images by means of comparing distance measurements on the 3D images with direct measurements of dry human skull according to slice thickness and scanning modes. Materials and Mathods : An observer directly measured the distance of 21 line items between 12 orthodontic landmarks on the skull surface using a digital vernier caliper and each was repeated five times. The dry human skull was scanned with a Helical CT with various slice thickness (3, 5, 7 mm) and acquisition modes (Conventional and Helical). The same observer measured corresponding distance of the same items on reconstructed 3D images with the internal program of V-works 4.0/sup TM/(Cybermed Inc., Seoul, Korea). The quantitative accuracy of distance measurements were statistically evaluated with Wilcoxons' two-sample test. Results: 11 line items in Conventional 3 mm, 8 in Helical 3mm, 11 in Conventional 5mm, 10 in Helical 5mm, 5 in Conventional 7mm and 9 in Helical 7mm showed no statistically significant difference. Average difference between direct measurements and measurements on 3D CT images was within 2mm in 19 line items of Conventional 3mm, 20 of Helical 3mm, 15 of Conventional 5mm, 18 of Helical 5mm, II of Conventional 7mm and 16 of Helical 7mm. Conclusion: Considering image quality and patient's exposure time, scanning protocol of Helical 5mm is recommended for 3D image analysis of the skull in CT.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.2
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• pp.173-181
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• 2014

In this paper, the algorithm that can automatically segment the lung, the airway and the pulmonary vessels in a chest CT was proposed. The proposed method is progressed in three steps. In the first step, the lung and the airway are segmented by the region growing law through the optimal threshold and three-dimensional labeling. In the second, from the start point to the first carina of the airway is segmented by the deduction operation, and the next airway of the bifurcations are segmented by applying a variable threshold technique. In the third step, the left/right lungs are divided by the restoration process for the lung, and the outside of lungs for abnormal is checked by applying the advanced rolling ball algorithm, and if abnormal is found, that part is removed, and it is restored to the normal lungs by connecting the outside of the lung in the form of second-order polynomial. Finally, pulmonary vessels are segmented by applying the three-dimensional connected component labeling method and three-dimensional region growing method. As the results of simulation, it could be confirmed that the pulmonary vascular is accurately divided without loss of tissue around lung.

• Journal of the Korean Wood Science and Technology
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• v.48 no.3
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• pp.283-290
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• 2020

For visual inspection-based wood identification, optical microscopy techniques typically require a relatively large sample size, and a scanning electron microscope requires a clean surface. These novel techniques experience limitations for objects with highly limited sampling capabilities such as important and registered wooden cultural properties. Synchrotron X-ray microtomography (SR-µCT) has been suggested as an effective alternative to avoid such limitations and various other imaging issues. In this study, four pieces of wood fragments from wooden members used in the Manseru pavilion of Bongjeongsa temple in Andong, Korea, wereused for identification. Three-dimensional microstructural images were reconstructed from these small wood samples using SR-µCT at SPring-8. From the analysis of the reconstructed images, the samples were identified as Zelkova serrata, Quercus sect. Cerris, and Pinus koraiensis. The images displayed sufficient spatial resolution to clearly observe the anatomical features of each species. In addition, the three-dimensional imaging allowed unlimited image processing.

• Archives of Craniofacial Surgery
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• v.16 no.2
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• pp.58-62
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• 2015

Background: Age-related changes have been studied for lower and middle facial bones. Although the forehead comprises one-third of the facial area, no studies have investigated age-related changes in the upper part of the face or forehead. The purpose of this study was to use three-dimensional computed tomography (3D CT) to investigate age-related changes in the frontal bone. Methods: A retrospective review was performed for patients who underwent 3D CT scan of facial bones. Patients were divided by gender and age (20 to 40 years, 41 to 60 years, and above 60 years). The frontal bone curvature was evaluated by the length of frontal bone and by two frontal bone angles in relation to the Frankfurt horizon. Results: In both genders, aging was associated with increasing lower slope length. In elderly men (>60 years), the upper slope angle was significantly higher when compared to younger male subjects. Women demonstrated similar age-related changes, but the differences were only statistically significant for the middle and older age groups. Conclusion: This study demonstrates quantifiable age-related changes in the frontal bone. These findings contribute to the understanding of age-related changes of the facial soft tissues. The mean measurements in each age group can be used as a reference when planning forehead reconstruction.

• Journal of Biomedical Engineering Research
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• v.15 no.2
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• pp.201-208
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• 1994

Many three-dimensional object modeling and display methods for computer graphics and computer vision have been developed. Recently, with the help of medical imaging devices such as computerized tomography, magnetic resonance image, etc., some of those object modeling and display methods have been widely used for capturing the shape, structure and other properties of real objects in many medical applications. In this paper, we propose the reconstruction and display method of the three-dimensional object from a series of the cross sectonal image. It is implemented by using the automatic threshold selection method and the contour following algorithm. The combination of curvature and distance, we select feature points. Those feature points are the candidates for the tiling method. As a results, it is proven that this proposed method is very effective and useful in the comprehension of the object's structure. Without the technician's responce, it can be automated.

• Journal of Chest Surgery
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• v.44 no.5
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• pp.368-372
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• 2011

This study was conducted to investigate the clinical application of three-dimensional (3D) reconstructed computed tomography (CT) images in detecting and gaining information on esophageal foreign bodies (FBs). Two patients with esophageal FBs were enrolled for analysis. In both cases, 3D reconstructed images were compared with the FB that was removed according to the object shape, size, location, and orientation in the esophagus. The results indicate the usefulness of conversion of CT data to 3D images to help in diagnosis and treatment. Use of 3D images prior to treatment allows for rapid prototyping and surgery simulation.

• Transactions of Materials Processing
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• v.20 no.7
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• pp.518-523
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• 2011

The three dimensional geometries of an aluminum open cell foam before and after uniaxial compressive loading were investigated using the X-ray micro CT(computed tomography). Aluminum 6101-T6 open cell foams of 10, 20, 40 ppi (pore per inch) were considered in this work. After the serial sectioning CT images of aluminum foams were obtained from non-destructive X-ray images, the exact 3D structure were reproduced and visualized with commercial image processing program. The relative density ratio was around the 7.0 to 9.0 range, the unit cells showed anisotropic shapes having the different dimensional ratios of 1.1 to 1.3 between the rise and the transverse directions. The yield stress increased with the relative density ratio and the volumetric strain increased proportionally with compressive strain. The plateau stress in the compressive stress-strain curve was caused by the buckling of ligaments.

• The Journal of Engineering Geology
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• v.20 no.4
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• pp.461-465
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• 2010

Weathering and permeability in rocks play a very important role in underground disposal of radioactive waste and their long-term management as well as stability security of rock structures. Weathering and permeability of rocks are largely controlled by the characters of inner structures of rocks. In other words, weathering rate can be accelerated depending on the quantity of pore and microcrack in rocks. Quantitative evaluation of inner structures of rocks can serve as a tool that can assess the degree of weathering of rocks. Therefore it can be said that the understanding of three dimensional distribution of the inner structure of rocks is important for long-term management of rock structures. This study was performed to analyze three dimensional distribution of pore in rocks using Micro Focus X-ray CT on fresh granite and weathered granite from Korea. Results of the analysis clearly show distribution of pore and porosity of the inner rock.