• Journal of radiological science and technology
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• v.37 no.4
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• pp.295-305
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• 2014

This study is to provide accurate information as medical imaging equipment to check for the presence of body disease US equipment. We investigated the status of medical US equipment performance in Daegu and criteria US phantom (ATS-539) for US equipment performance measurements. The results in this study, 1. US phantom measurement results: The test passed rate were 88.6% and the failed rate were 11.4%. 2. The difference between the group of mean and the pass/failed groups were statistically significant. Focal zone and 4 mm functional resolution in the two items that are not present the passing standard. 3. The difference was statistically significant number of years and used equipment and pass the failed equipment (4.13 vs 7.25 years). We investigated the performance status of US equipment used in the clinical area in Daegu. The basis for the two items are not present this proposed passing standard. Equipment performance was associated with the number of years of using US equipment. It is necessary to maintain the best performance of the equipment phantom measurements for performance testing of US equipment.

• Journal of the Korean Society of Radiology
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• v.11 no.5
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• pp.371-377
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• 2017

General phantom for practical X-ray photography Practical phantom is an indispensable textbook for radiology, but it is difficult for existing commercially available phantom to be equipped with various kinds of phantom because it is an expensive import. Using 3D printing technology, I would like to make the general phantom for practical X-ray photography less expensive and easier. We would like to use a skeleton model that was produced based on CT image data using a 3D printer of FDM (Fused Deposition Modeling) method as a phantom for general X-ray imaging. 3D slicer 4.7.0 program is used to convert CT DICOM image data into STL file, convert it to G-code conversion process, output it to 3D printer, and create skeleton model. The phantom of the completed phantom was photographed by X - ray and CT, and compared with actual medical images and phantoms on the market, there was a detailed difference between actual medical images and bone density, but it could be utilized as a practical phantom. 3D phonemes that can be used for general X-ray practice can be manufactured at low cost by utilizing 3D printers which are low cost and distributed and free 3D slicer program for research. According to the future diversification and research of 3D printing technology, it will be possible to apply to various fields such as health education and medical service.

• Journal of the Korean Society of Radiology
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• v.13 no.2
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• pp.185-192
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• 2019

DXA is the most commonly used BMD examination equipment with the best performance on reflecting the biological alteration with tiny change of bone density. In spite of the importance of the quality control to maintain the accuracy and precision of the examination, considerable number of hospitals are not conducting QC due to the difficulty and high cost of the phantom product. This study develops the cross revision phantom with 3D printer and the change of the degree of infilling filaments which can be readily secured, and provides the usefulness assessment of the developed phantom by comparing with existing products. The Hounsfield Units of ABS, TPU, PLA, 30% Cu-PLA, and 30% Al-PLA are assessed. The Hounsfield Units result at infilling rate 100% was $-149.74{\pm}2.36$, $-55.62{\pm}7.14$, $-7.68{\pm}3.82$, $87.53{\pm}1.07$, and $1795.20{\pm}16.15$. The L1, L2, L3 BMD of 3D printing phantom with linear regression model were $0.620{\pm}0.010g/cm^2$, $1.092{\pm}0.025g/cm^2$, $1.554{\pm}0.026g/cm^2$ which are statistically relevant to the existing phantom products. This result provides the base line data for various medical phantom produce and capability of proper quality control of DXA equipment.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.4
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• pp.368-373
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• 2009

A human tissue mimicking phantom is constructed to assess the performance of a medical ultrasound elasticity imaging system. In a human body, the tumor or cancer is stiffer than its surrounding normal tissue. A technique fur imaging the elasticity of such a tissue is referred to as elastography. Homogeneous elasticity phantoms with differing Young's moduli are constructed using a plastic hardener and softener to simulate the mechanical characteristics of a diseased human tissue. The Young's modulus of the fabricated homogeneous phantom materials were measured from 11.1 to 79.6 kPa depending on the mixing ratio of the amount of the hardener to that of the softener. An ultrasound lesion mimicking phantom was made of these materials, and ultrasound elasticity imaging was performed on it. It is confirmed in this paper that the fabricated plastic-based elasticity phantom is useful in representing the elastic characteristics of a human tissue.

• Progress in Medical Physics
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• v.23 no.4
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• pp.229-233
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• 2012

A small water phantom (dual-window phantom) was developed to improve the output measurement efficiency of medical linacs. This phantom is suitable for determining the quality index and output dose for high-energy photon beams. The phantom has two opposite windows and two independently rotating axes. The two axes measure the tissue phantom ratio (TPR) and the percentage depth dose (PDD) simply without requiring chamber movement by rotating the phantom around its axis. High-energy photon beams from a Co-60 irradiator and a medical linac were used to evaluate the phantom. The measured quality index is in good agreement with the reference values; the measured and reference values are within 0.2% of each other for the Co-60 gamma rays and within 1.4% for 6 and 10 MV X-rays. This phantom is more practical for routine output measurements, resulting in the prevention of potential human errors.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2003.09a
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• pp.51-51
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• 2003

국민건강보험재정건전화특별법 (제정 2002.1.19 법률 제 6620호)은 건강보험의 재정적자를 조기에 해소하고 재정수지의 균형을 이루도록 함으로써 건강보험제도의 발전과 국민건강 증진 도모를 그 목적으로 하며, 제14조(특수의료장비의 설치ㆍ운영)에서 의료기관은 보건복지부장관이 고시한 특수의료장비를 설치ㆍ운영하고자 하는 때에는 보건복지부령이 정하는 바에 따라 이를 등록하여야 하며 설치 인정 기준에 적합하게 설치ㆍ운영하여야 하고 정기적인 품질관리를 받아야한다고 명시하였다. 특수 의료장비의 설치 및 운영에 관한 규칙 (제정 2003.1.14 보건복지부령 제235호)은 국민건강보험재정건전화특별법이 제정됨에 따라 특수의료장비의 적정 한 설치와 활용을 위하여 의료기관에서 설치ㆍ운영하는 특수의료장비의 등록절차 설치인정기준 및 품질관리 절차 등을 정하고 특수의료장비에 대한 관리체계를 확립하려는 것이다. 특수의료장비의 설치 및 운영에 관한 규칙의 주요 골자는 가. 의료기관에서 특수장비를 설치ㆍ운영하고자 하는 경우 보건복지부장관 또는 시ㆍ도 지사에게 등록하도록 하였는바, 이 등록에 대한 절차와 특수의료장비의 설치인정기준을 정함, 나. 특수의료 장비에 대한 정기적인 품질관리검사를 서류검사와 정밀감사로 구분하여 서류검사는 1 년마다, 정밀검사는 3 년마다 받도록 함, 다. 품질관리검사기관의 장은 특수의료장비품질관리검사성적서를 신청인에게 교부하고, 보건복지부 또는 시ㆍ도지사 및 건강보험심사평가위원장에게 검사결과를 통보하도록 함, 라. 특수의료정비를 설치ㆍ운영하는 의료기관의 개설자 또는 관리자 및 품질관리검사기관의 장이 작성ㆍ비치ㆍ보존하여야할 서류를 정함이다. 보건복지부장관에게 등록하여야할 특수의료장비는 자기공명영상촬영장치와 전산화단층촬영 장치이며, 시ㆍ도지사에게 등록하여야할 특수의료장비는 유방촬영용장치이다. 본 발표에서는 특수의료장비의 설치 및 운영에 관한 규칙에 대한 개요와 연세의료원 세브란스병원에서 시행하고 있는 특수의료장비의 정도관리 검사, 팬텀영상검사, 그리고 임상영상검사를 소개하고자한다.

• The Journal of the Korea Contents Association
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• v.7 no.7
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• pp.114-123
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• 2007

The increasing use of computed tomography (CT) as a diagnostic tool creates the need from and efficient means of evaluating the performance of the CT scanner now in use. Accordingly, acceptance testing and quality assurance of CT is of great importance. The aim of this study is to analyze of AAPM CT performance phantom in the CT accreditation program. The modular phantom offers the CT system with which to measure eight performance parameters. The parameters are listed of CT attenuation coefficient of water, noise, uniformity, spatial resolution, contrast resolution, slice thickness (5 and 10 mm), artifacts and alignment. The phantom evaluation was done by two radiologists. The acceptance testing protocol described here in demonstrates the successful of the guidelines for the quality assurance using AAPM CT performance phantom. We need to be upgraded for the CT image quality and make the standard reference of the quality assurance in the CT.

• Journal of Biomedical Engineering Research
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• v.22 no.2
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• pp.165-169
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• 2001

최근 포항 방사광 가속기 연구소에 미세구조 X-선 영상 실험을 위한 5C1 방사광(Synchrtoron Radiation) 빔라인이 건설되었다. 광대역의 에너지 스펙트럼을 가진 방사광 X-선이 물체를 투과한 후 CdWO$_{4}$ scintillator에 의해 가시광선으로 바뀌고, 그 빛을 CCD 카메라로 받아들여 영상을 획득하게 된다. 방사광 X-선은 일반 의료진단용 X-선에 비하여 위상이 일치하고, 평행하며, 그 양이 풍부한 특성들을 갖고 있다. 방사광 영상시스템과 X-선 유방촬영 시스템에서 영상을 획득하여 영상특성들을 비교, 분석하였다. 고-분해능 X-선 시험 패턴(20 line pairs mm$^{-1}$), 유방촬영 팬텀, 파라핀에 고정한 인체 유방암조직과 포르말린에 고정한 인체 유방암조직, 그리고 capillary tube내 micro-bubbles등의 방사광 영상은 기존의 X-선 유방촬영시스템에서 얻은 영상보다 분해능이 뛰어나고 영상질도 우수하였다. 방사광 X-선 영상시스템은 micrometer 공간 분해능 영상을 획득할 수 있어 많은 기초분야의 영상연구와 의료영상분야에서도 활발하게 활용될 것으로 기대된다.

• The Journal of the Acoustical Society of Korea
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• v.29 no.8
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• pp.504-508
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• 2010

In conventional diagnostic ultrasound strain imaging, when displaying strain image on a monitor, human visual characteristics are utilized such that hard regions are displayed as dark and soft regions are displayed as bright. Thus, hard regions representing tumor or cancer are displayed as dark, decreasing the contrast inside the lesion. Because the lesion area is stiff and thus displayed as dark, a method of inverting the image brightness and thereby increasing the contrast in the lesion for better diagnostic purposes is proposed wherein a postcompression signal is extended in the time domain by a factor corresponding to the reciprocal of the amount of the applied compression using a technique termed globally uniform stretching. Experiments were carried out to verify the proposed method on an ultrasound elasticity phantom with radio-frequency data acquired from a diagnostic ultrasound clinical scanner. It is found that the new method improves the contrast-to-noise ratio by a factor of up to about 1.8 compared to a conventional strain imaging method that employs a reversed gray color map without globally uniform stretching.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.84-91
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• 2017

This study was performed using Somatom Definition Flash (Siemens, Enlarge, Germany) and GE 64-MDCT (Discovery 750 HD, GE HEALTHCARE, Milwaukee, USA.) using high-density medical materials that (are indispensable to?) computed tomography. We analyzed quantitatively the rate of change of the CT number of the CT reconstruction images by means of the IMAR and MAR algorithms using the phantom images acquired after scanning and previously captured raw data images. As a result, it was shown that the IMAR and MAR algorithms provided if ferent phantom images in the case of all medical high-density materials (p <0.05). The black streak artifacts were analyzed using the MAR and IMAR algorithms to determine if they corresponded to stainless steel materials (p>0.05). Also, it was found that the application of the IMAR algorithm affects the attenuation deviation, because there is a change in the image CT number compared to that before. The results suggest that, in the future, after the implant procedure, it would be useful to observe the surgical site and surrounding tissues during follow-up CT scans.