• Journal of the Korean Society for Precision Engineering
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• v.25 no.1
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• pp.51-62
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• 2008

• Proceedings of the Korean Society of Radiological Science
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• 1991.05a
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• pp.13.1-13.1
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• 1991

• Journal of Veterinary Clinics
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• v.31 no.6
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• pp.495-501
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• 2014

The objective of this study was to evaluate the differences and reproducibility of Hounsfield unit (HU) value and volume measurements on different computed tomography (CT) scanner types and different collimations by using a gelatin phantom. The phantom consisting of five synthetic simulated calculus spanning diameters from 3.0 mm to 12.0 mm with 100 HU was scanned using a two-channel multi-detector row CT (MDCT) scanner, a four-channel MDCT scanner, and two 64-channel MDCT scanners. For all different scanner types, the thinnest possible collimation and the second thinnest collimation was used. The HU values and volumes of the synthetic simulated calculus were independently measured three times with minimum intervals of 2 weeks and by three experienced veterinary radiologists. ANOVA and Scheff$\acute{e}$ test for the multiple comparison were performed for statistical comparison of the HU values and volumes of the synthetic simulated calculus according to different CT scanner types and different collimations. The reproducibility of the HU value and volume measurements was determined by calculating Cohen's k. The reproducibility of HU value and volume measurements was very good. HU value varied between different CT scanner types, among different beam collimations. However, there was not statistically significant difference. The percent error (PE) decreased as the collimation thickness decreased, but the decrease was statistically insignificant. In addition, no statistically significant difference in the PEs of the different CT scanner types was found. It can be concluded that the CT scanner type insignificantly affects HU value and the volumetric measurement, but that a thinner collimation tends to be more useful for accurate volumetric measurement.

• 대한예방의학회:학술대회논문집
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• 1996.10a
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• pp.349-350
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• 1996

• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.597-603
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• 2019

We obtained a Dicom file using a CT (Computed Tomography), a diagnostic test device used in clinical practice. Dicom files and 3D programs, and finger printers with 3D printers. Because the finger brace is intended for the human body, the accuracy of the shape is very important. 3D Print has the advantage of high precision, variety of materials, and short output time. In clinic, aluminum protector or medical device manufacturer's finger protector is limited. By creating a finger brace with a 3D printer, we expect to be able to apply a precise form of a custom finger brace to the patient that can be used to treat a patient's finger trauma, illness, or deformity.

• Journal of Chest Surgery
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• v.31 no.3
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• pp.298-303
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• 1998

Computerized tomography(CT) is an effective technique in the initial evaluation of the abdomen and head following blunt trauma. To evaluate the efficacy of CT of the thorax, a retrospective study comparing early thoracic CT scanning with initial chest roentgenogram (CXR) was carried out on 134 patients with blunt trauma on the chest. Among 134 patients, 45 patients had normal initial chest roentgenogram and 24 patients showed normal CT findings. Sensitivities of diagnosing pneumothorax and pleural effusion by CXR were low (46.2 and 62.9% respectively), whereas 71.4%(45/63) of patients had thoracostomy only by CXR. Although sometimes abused, CT of the thorax is effective in the initial diagnosis.

• Journal of the Korean Society of Radiology
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• v.13 no.7
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• pp.947-953
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• 2019

The purpose of this study was to manufacture a wrist brace using a computerized tomography system, clinical design software (MediACE 3D Program), and 3D printer. After acquiring the Dicom file of the upper limb with a computed tomography, the wrist brace was designed using the MediACE 3D Program to create a "stereolithography" file. The designed wrist brace was printed using a 3D printer. To verify the effectiveness of wrist assistive device manufactured by 3D printing technology, the stress distribution of the pressure and orthosis applied to bone and skin is represented by finite element analysis. It is expected that the wrist brace can be manufactured by reinforcing the part where the damage caused by pressure and breakage of the brace frequently occurs with the result of finite element analysis when producing the wrist brace.

• Journal of radiological science and technology
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• v.14 no.1
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• pp.29-44
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• 1991

A Study on the distribution and types of the total 40 CT units, as of 1st October 1990, in Pusan area(29 for whole body CT units, 11 for brain CT units) were carried out during the period from January 1989 to December 1989 to find out the status of operation and utilization of whole body CT units. The results were as following ; 1. As of 1st October 1990 in Pusan area, a total of 40 CT units(29 for whole body CT units, 11 for brain CT units) were set up and operated. The number of cases of CT examination performed per day per unit were appeared to be less than 5 cases among 59.5% of CT units, and 2.7% of the total units has peformed more than 16 examinations. 2. The CT units under operation occupied 93.5% of the total and 2.6% of the total units was not properly been operated due to mechanical breakdown. This results is appeared to be better than other reports. 3. The average number of scanning per week for each CT were 35 cases and the average days under operation of the unit per week were 6.7 days. Consequently, the average days under operation of units was higher than that of the other reports, but the average number of scanning was lower. 4. The cases referred from other institutes to hospitals were 6.4% of total cases. 5. As a site of scanning, the brain appeared most frequently with 71.2% of the total cases and followed by spine 12.4%, abdomen 8.5%, and thorax 3.6%, respectively. 6. Positive rate by scanning was 70.8% of total cases, and it was 98.9% with thorax, abdomen 96.3%, spine 93.1%, and brain 38.4%, respectively. According to the results of this study, it is highly recommended that the regulations and the guidelines for setting-up of such high cost medical equipments as CT units be provided in order to ensure the cost-effectiveness of the system.

• Journal of Preventive Medicine and Public Health
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• v.30 no.1 s.56
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• pp.195-207
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• 1997

High price equipment is one of the major factors that increases national health expenditure in developed countries. Computerized Tomography(CT), one of the important high price equipment, has been concerns of health service researchers and policy makers in many countries. In Korea, CT, first introduced in 1984, have spreaded nationwide with rapid speed. Though the Committee for Approving Import of High Price Medical Equipment, founded in 1981, tried to regulate the introduction of high price medical equipment including CT, the effort resulted in failure. The exact situation of diffusion of the high price equipment, however, was not yet investigated. We aimed at the description of the diffusion of CT in Korea and analysis of influencing factors on hospitals for the adoption of CT. We mainly used the database of CT, made in 1996 by the National Federation of Medical Insurance for the purpose of insurance payment for CT. Also characteristics of hospitals were gathered from yearbooks published by the central and local governments and by the Korean Hospital Association. We calculated the cumulative number of the CT per one million population year by year. In turn, multiple linear logistic regression was done to find out the contributing factors for the adoption of CT by each hospital. In the logistic regression model, it is regarded as dependent factor whether a hospital retained CT or not in 1988 and 1993. The major categories of the independent factors were hospital characteristics, environmental factors and competitive conditions of hospitals at the period of the adoption. The results are as follows: Number of CT scanners per one million persons in Korea marked more higher level compared with those of most OECD countries. Major influencing factors on the adoption of CT scanners were hospital characteristics, such as hospital referral level, and competitive condition of hospitals, such as number of CT scanners per 10,000 persons in each district where the hospital was located. In Korea, CT diffused with rather rapid speed, comparable with those of the United States and Japan. The major factors contributing on the adoption of CT for hospitals were competitive condition and hospital characteristics rather than regional health care need for CT. In conclusion, a kind of regulating mechanism would be necessary for the prevention of the indiscreet adoption and inefficient use of high price equipment including CT.

• Journal of the Korean Society of Radiology
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• v.15 no.5
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• pp.585-590
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• 2021

Wrist braces are being used for patients with wrist trauma. Recently, many studies have been conducted to manufacture custom wrist braces using 3D printing technology. Such 3D printing customized orthosis has the advantage of reflecting various factors such as reflecting different shapes for each individual and securing breathability. In this paper, the stress on the orthosis by the number and position of Velcro bands that should be considered when manufacturing a 3D printing custom wrist brace was analyzed. For customized orthosis, 3D modeling of the bone and skin regions was performed using an automatic design software (Reconeasy 3D, Seeann Solution) based on CT images. Based on the 3D skin area, a wrist orthosis design was applied to suit each treatment purpose. And, for the elasticity of the brace, a wrist brace was manufactured with an FDM-type 3D printer using TPU material. To evaluate the effectiveness according to the number and position of the Velcro band of the custom 3D printed wrist brace, the stress distribution of the brace was analyzed by the finite element method (FEM). Through the finite element analysis of the wrist orthosis performed in this study, the stress distribution of the orthosis was confirmed, and the number and position of the orthosis production and Velcro bands could be confirmed. These experimental results will help provide quality treatment to patients.