• Korean Journal of Computational Design and Engineering
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• v.15 no.3
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• pp.234-242
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• 2010

3D CAD technology has been extended to a medical area including dental clinic beyond industrial design. The 2D images obtained by CT(Computerized Tomography) and MRI(Magnetic Resonance Imaging) are not intuitive, and thus the volume rendering technique, which transforms 2D data into 3D anatomic information, has been in practical use. This paper has focused on a method and its implementation for forming 3D geometric surface model from laminated CT images of the pubis. The implemented system could support a dental clinic to observe and examine the status of a patient's pubis before implant surgery. The supplement of 3D implant model would help dental surgeons settle operation plans more safely and confidently. It also would be utilized with teaching materials for a practice and training.

• Archives of Plastic Surgery
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• v.33 no.2
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• pp.175-180
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• 2006

Preoperative angiography is frequently used in the planning of microsurgical reconstruction for identification of vascular abnormality that influence the planning of operation. But, recently 3D CT angiography is considered as new technique that can provide detailed information about vascular anatomy as well as soft and bony tissue without the risks of invasive angiography. 3D CT angiograms were performed in 19 patients before microsurgical reconstruction for the lower extremity and hand between May of 2003 and Oct of 2004. Sixteen of the studies were of the donor site and all of 19 studies were of the recipient site. No complications were found from the 3D CT angiograms. In one case of the bone exposed open wound, the injury of anterior tibial artery was identified and the zone of injury was adequately demonstrated. With the improvement in quality of CT imaging, 3D CT angiograms may provide a favorable alternative to invasive angiography. It is capable of providing high-resolution, three dimensional vascular imaging without the need for arterial puncture and prolonged post-procedure observation. The relation among blood vessels, bones, and soft tissue is well demonstrated in 3D CT angiogram. Also The acquisition time and examination cost were considerably lower in comparison with invasive angiography. In conclusion, this study demonstrates that 3D CT angiography may provide accurate, safe, and cost-effective preoperative imaging. The 3D CT angiography with relatively low morbidity, low cost, ease of image acquisition can have an broader role in microsurgical reconstructive surgery.

• Journal of radiological science and technology
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• v.45 no.5
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• pp.423-431
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• 2022

The purpose of this study is to present objective information in applying 3D printing technology for PET/CT (Positron Emission Tomography/Computed Tomography) performance evaluation and use it as a basic research that can be applied to various purposes in the future. Phantoms were manufactured with step wedge of ABS(Acrylonitrile Butadiene Styrene) and ACR(Acrylic acid) material. The counts for each ROI(Region of Interest) were analyzed through image acquisition in PET/CT. And the variation rate of counts and CNR(Contrast Noise Ratio) was evaluated. In the counts analysis, the effect of thickness occurred. In addition, in the variation rate analysis, the thickness setting of steps wedge 4 to 5 levels should be considered first. These results minimize quantitative and qualitative changes in the phantom manufactured based on 3D printing, and enable more stable PET/CT performance evaluation. Based on 3D printing in PET/CT, various phantoms are expected to be produced in the future. If the characteristics of each material are considered and applied through the basic research such as this research, the result of the phantom manufactured through 3D printing can be more meaningful and will be used in a wide range.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.40 no.3
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• pp.123-129
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• 2014

Objectives: The aim of this study was to verify the concordance of the measurement values when the same cephalometric analysis method was used for two-dimensional (2D) cephalometric radiography and three-dimensional computed tomography (3D CT), and to identify which 3D Frankfort horizontal (FH) plane was the most concordant with FH plane used for cephalometric radiography. Materials and Methods: Reference horizontal plane was FH plane. Palatal angle and occlusal plane angle was evaluated with FH plane. Gonial angle (GA), palatal angle, upper occlusal plane angle (UOPA), mandibular plane angle (MPA), U1 to occlusal plane angle, U1 to FH plane angle, SNA and SNB were obtained on 2D cephalmetries and reconstructed 3D CT. The values measured eight angles in 2D lateral cephalometry and reconstructed 3D CT were evaluated by intraclass correlation coefficiency (ICC). It also was evaluated to identify 3D FH plane with high degree of concordance to 2D one by studying which one in four FH planes shows the highest degree of concordance with 2D FH plane. Results: ICCs of MPA (0.752), UOPA (0.745), SNA (0.798) and SNB (0.869) were high. On the other hand, ICCs of gonial angle (0.583), palatal angle (0.287), U1 to occlusal plane (0.404), U1 to FH plane (0.617) were low respectively. Additionally GA and MPA acquired from 2D were bigger than those on 3D in all 20 patients included in this study. Concordance between one UOPA from 2D and four UOPAs from 3D CT were evaluated by ICC values. Results showed no significant difference among four FH planes defined on 3D CT. Conclusion: FH plane that can be set on 3D CT does not have difference in concordance from FH plane on lateral cephalometry. However, it is desirable to define FH plane on 3D CT with two orbitales and one porion considering the reproduction of orbitale itself.

• Korean Journal of Head & Neck Oncology
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• v.26 no.2
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• pp.193-197
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• 2010

Objectives : Patients with neck tumor and their family need every information about the disease. Especially, the size and location are confusing with verbal information. With the aid of CT, the problem had some answer, but it needs some medical education. We would like to know the usefullness of 3D reconstructed images in patient education about the disease. Material and Methods : Neck CT data were collected from 10 patients with various neck tumors and converted to 3D reconstructed images. Understanding of the patients about the size and location of tumors were rated from questionaires using axial CT images and 3D images. Results : Understanding score about 3D images were greater than that of CT images(p<0.006). Conclusion : 3D reconstructed images of CT could give the patients more real visual information about the disease.

• Journal of the Korean Society of Radiology
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• v.17 no.6
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• pp.929-937
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• 2023

Human equivalent phantoms manufactured using 3D printers are cheaper and can be manufactured in a short time than conventional human phantoms. However, many phantoms are manufactured with less than 100 % of Infill Density, one of the 3D printer output setting variables. Therefore, this study compared the Bone Phantom CT number, which differs from the ratio of five Infill Density produced using a 3D printer, to the CT number of the actual human body Bone. In addition, the usefulness of the manufactured phantom was evaluated by producing a 100 % elbow joint phantom with Infill Density and setting the Infill Density to 100 % through CT number comparison for each tissue on computed tomography (CT). As a result, the Bone Phantom printed with 100 % Infill Density did not show the most statistically significant difference from the CT number value of the actual human Bone, and the CT number of each tissue did not show a statistically significant difference from the CT number value of each tissue of the actual human elbow joint.

• Journal of radiological science and technology
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• v.34 no.2
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• pp.105-116
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• 2011

In this study, we present the measurements of effective dose from CT of head & neck region. A series of dose measurements in anthropomorphic Rando phantom was conducted using a radio photoluminescent glass rod dosimeter to evaluate effective doses of organs of head and neck region from the patient. The experiments were performed with respect to four anatomic regions of head & neck: optic nerve, pons, cerebellum, and thyroid gland. The head & neck CT protocol was used in the single scan (Brain, 3D Facial, Temporal, Brain Angiography and 3D Cervical Spine) and the multiple scan (Brain+Brain Angiography, Brain+3D Facial, Brain+Temporal, Brain+3D Cervical spine, Brain+3D Facial+Temporal, Brain+3D Cervical Spine+Brain Angiography). The largest effective dose was measured at optic nerve in Brain CT and Brain Angiography. The largest effective dose was delivered to the thyroid grand in 3D faical CT and 3D cervical spine, and to the pons in Temporal CT. In multiple scans, the higher effective dose was measured in the thyroid grand in Brain+3D Facial, Brain+3D Cervical Spine, Brain+3D Facial+Temporal and Brain+3D Cervical Spine+Brain Angiography. In addition, the largest effective dose was delivered to the cerebellum in Brain CT+Brain Angiography CT and higher effective dose was delivered to the pons in Brain+Temporal CT. The results indicate that in multiple scan of Brain+3D Cervical Spine+Brain Angiography, effective dose was 2.52 mSv. This is significantly higher dose than the limitation of annual effective dose of 1 mSv. The effective dose to the optic nerve was 0.31 mSv in Brain CT, which shows a possibility of surpassing the limitation of 1 mSv by furthre examination. Therefore, special efforts should be made in clinical practice to reduce dose to the patients.

• Journal of Biomedical Engineering Research
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• v.20 no.5
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• pp.581-586
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• 1999

척추의 생체역학적 해석을 위한 유한요소기법을 이용한 컴퓨터 시뮬레이션은 척추의 손상에 대한 발생원인과 기전을 이해하고 치료의 효과를 예측하는 유용한 수단으로 기대되고 있다. 본 논문에서는 요추의 2차원 CT 영상을 이용하여 유한요소해석을 위한 척추의 3차원 모델링에 소비되는 많은 시간을 줄일 수 있도록 3차원 형상모델을 CT 형상 데이터와 형상변수를 이용, 각각 구현하는 과정을 자동화하여 이를 비교하였다.

• The korean journal of orthodontics
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• v.40 no.1
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• pp.6-15
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• 2010

Objective: The aim of this study is to find the most helpful midsagittal reference plane for diagnosis in PA cephalometry compared with 3D CT. Methods: The subjects consisted of 25 adults who showed no facial asymmetry by gross inspection. 3D CT and posteroanterior cephalogram of the subjects were taken. To find the most helpful midsagittal reference plane in PA cephalometry, we considered five kinds of midsagittal planes from which the distances to five landmarks were measured and compared the result with that of 3D CT. The midsagittal plane for 3D CT was determined by the landmarks Nasion, Sella and Basion. Results: PA measurements using the midsagittal reference plane on a perpendicular plane lying through the midpoint of the right and left latero-orbitales was closest to those of 3D CT. Conclusions: It was considered that latero-orbitale perpendicular could be used as the helpful midsagittal reference plane to assess facial asymmetry in PA cephalometry.

• Archives of Plastic Surgery
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• v.34 no.2
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• pp.265-268
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• 2007

Purpose: Superficial temporal artery(STA) aneurysms are very rare and mostly occur as pseudoaneurysms secondary to trauma. Clinical diagnosis of STA pseudoaneurysm is based on a history of trauma or surgery to frontotemporal region, which presents with pulsatile mass. To confirm diagnosis, many imaging strategies can be used such as digital subtraction angiography, sonography, CT and MRI. But, these imaging modalities are invasive or inaccurate or expensive. Thus, we used 3D CT angiography to confirm STA aneurysm and to get accurate information. Methods: We have experienced two cases of pulsatile mass on the temporal area, suspected as STA pseudoaneurysms. On the basis of clinical information, we performed 3D CT angiography to get more accurate information about this pulsatile mass and to confirm diagnosis. On the basis of information from 3D CT angiography, we performed operation. Results: The lesions were diagnosed as pseudoaneurysm of superficial temporal artery by 3D CT angiography, and surgically resected safely without any complication on the basis of information from 3D CT angiography. 3D CT angiography was excellent diagnostic method for detecting STA pseudoaneurysms, and effectively showed many information about pseudoanerysms such as relationship between the aneurysms and surrounding structures, and its size. Conclusion: We could effectively diagnose and treat on the basis of information from 3D CT angiography. We present our cases with a brief review of the literature related to STA traumatic pseudoaneurysms.