• Imaging Science in Dentistry
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• v.47 no.2
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• pp.99-107
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• 2017

Purpose: Erosions and osteophytes are radiographic characteristics that are found in different stages of temporomandibular joint (TMJ) osteoarthritis. This study assessed the effectiveness of digital subtraction radiography (DSR) in diagnosing simulated osteophytes and erosions in the TMJ. Materials and Methods: Five intact, dry human skulls were used to assess the effectiveness of DSR in detecting osteophytes. Four cortical bone chips of varying thicknesses (0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm) were placed at the medial, central, and lateral aspects of the condyle anterior surface. Two defects of varying depth (1.0 mm and 1.5 mm) were created on the lateral, central, and medial poles of the condyles of 2 skulls to simulate erosions. Panoramic images of the condyles were acquired before and after artificially creating the changes. Digital subtraction was performed with Emago dental image archiving software. Five observers familiar with the interpretation of TMJ radiographs evaluated the images. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic accuracy of the imaging methods. Results: The area under the ROC curve (Az) value for the overall diagnostic accuracy of DSR in detecting osteophytic changes was 0.931. The Az value for the overall diagnostic accuracy of panoramic imaging was 0.695. The accuracy of DSR in detecting erosive changes was 0.854 and 0.696 for panoramic imaging. DSR was remarkably more accurate than panoramic imaging in detecting simulated osteophytic and erosive changes. Conclusion: The accuracy of panoramic imaging in detecting degenerative changes was significantly lower than the accuracy of DSR (P<.05). DSR improved the accuracy of detection using panoramic images.

• Journal of the Korean Society of Radiology
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• v.11 no.5
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• pp.353-359
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• 2017

The sonophoresis, a representative low-intensity ultrasonic therapy, is a technique for delivering the drugs into the epidermis, dermis and skin appendages by using physical vibration and heat effects of the ultrasonic waves. Sonophoresis could increases the delivering and absorption efficiency of the drugs usually consisting of hydrophilic molecules and macromolecules. In addition, it has the advantage of being effective in delivering drugs with relatively large molecular sizes such as insulin or lipid. In this study, we proposed a multi-structure ultrasonic transducer assembly with a large-size single piezoelectric element and a drug delivery function at the treatment site for efficient sonophoresis treatment. Futhermore, a transducer assembly structure capable of raising and maintaining the temperature of the treatment site was proposed and evaluated for effectiveness. The transducer assembly proposed in this study is expected to improve the efficiency of sonophoresis by providing a constant amount of drug, and assisting drug delivery through heating the treatment site.

• Journal of radiological science and technology
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• v.30 no.1
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• pp.47-51
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• 2007

Development of hospital information system and Picture Archiving Communication System is not new in the medical field, and the development of internet and information technology are also universal. In the course of such development, however, it is hard to share medical information without a refined standard format. Especially in the department of radiology, the role of PACS has become very important in interchanging information with other disparate hospital information systems. A specific system needs to be developed that radiological reports are archived into a database efficiently. This includes sharing of medical images. A model is suggested in this study in which an internal system is developed where radiologists store necessary images and transmit them in the standard international clinical format, Clinical Document Architecture, and share the information with hospitals. CDA document generator was made to generate a new file format and separate the existing storage system from the new system. This was to ensure the access to required data in XML documents. The model presented in this study added a process where crucial images in reading are inserted in the CDA radiological report generator. Therefore, this study suggests a storage and transmission model for CDA documents, which is different from the existing DICOM SR. Radiological reports could be better shared, when the application function for inserting images and the analysis of standard clinical terms are completed.

• Journal of the Korean Society of Radiology
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• v.12 no.5
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• pp.693-698
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• 2018

Currently, shields for shielding medical radiation during medical examinations in the medical environment are lead robe and lead glass. Lead, the main component of this shielding, has limitations in lead poisoning and light weight, and high price. Iodine, which is used as contrast medium instead of lead shield, is expected to be effective as a shield because it has radiation absorbing properties. The purpose of this study was to evaluate the effectiveness of shielding by using acrylic plate filled with CT contrast agent for clinical use instead of conventional lead glass. As a result, it was found that the acrylic plate filled with the CT contrast agent showed a shielding effect of 7 times or more when the scattering ray dose was not shielded. Therefore, CT contrast agent composed of iodine is expected to be used as a shield instead of conventional lead glass.

• Journal of radiological science and technology
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• v.41 no.2
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• pp.97-102
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• 2018

The purpose of this study is to provide the basic data for reducing unnecessary radiation dose to the abdomen and fetus of pregnant women by presenting proper height of shielding protector for efficient abdominal shielding in chest PA examination of Korean pregnant women. The subjects of this study were 288 persons who were eligible for this study among 798 pregnant women who had chest PA examination from January 1, 2015 to December 31, 2016 Retrospective study was performed. Measurements was performed from the apex of the right and left lungs to costophrenic angle of the right and left lungs and to the lowest costophrenic angle among the right and left lungs at the top of the image(this line called Joo's line in this study). The mean of the right and left lung height of pregnant women were 259.09 mm and 263.57 mm, respectively. Also, the average height of the Joo's line designed by the researcher for proper abdominal radiation protection was 322.15 mm. For proper and efficient abdominal radiation protection for pregnant women, it is necessary to adjust the shielding according to the height of the pregnant woman. It is appropriate that the height of the shielding protector should be adjusted so that the upper part of the shield is located at 342.30 mm below from upper part of the detector.

• Journal of the Korean Society of Radiology
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• v.9 no.1
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• pp.17-21
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• 2015

Recently, As people's interest in the health of teeth is increased in the medical field changed into aging society, the number of times for the radiological diagnosis is increased. It can be said that the radiation exposure dose of Korean population is increased. It is also growing concern about radiation exposure. Therefore, the basic data for the dental panoramic X-ray system, its investigation and measuring the radiation dose is needed. In this study, we used ALOKA PDM-117 dosimeter and estimated a two-dimensional dose distribution of the dental panoramic X-ray system (VATEC Pax-400). Dose evaluation about the distribution is confirmed from the point of radiation exposure of a patient. Dose distribution of the dental panoramic X-ray system irradiated chin and the facial region to high dose as well as the parts of teeth. It was founded that the eye lens which are sensitive to radiation are exposed to unnecessary radiation, considering the effect of scattered radiation. The results of this study will be used more accurate dose assessment in a variety of object size and location of measuring dose.

• Journal of radiological science and technology
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• v.26 no.2
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• pp.43-47
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• 2003

Colorectal cancer produce focal mass or segmental thickening which can be detected with sonography. The purpose of this study was to describe sonographic findings of colorectal cancer. we reviewed sonograms of 51 patients with colorectal cancer in whom sonography was performed before colon study. In 51 patients who had more common coloretal cancer 27cases(53%) had 40 to 50 years of age(60%). Sonographic findings included segmental thickening 42cases, or irregular mass 9 cases. With careful examination, these findings can be detectable, and therefore bowel should be carefully examination in patients with sign and symptoms suggesting carcinoma of the colon and rectum.

• Journal of radiological science and technology
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• v.37 no.3
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• pp.203-209
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• 2014

Usefulness and clinical availability for surgery efficiency were evaluated by conducting pre-operative planning with a model manufactured by desktop 3D printer by using clavicle CT image. The patient-customized clavicle fracture model was manufactured by desktop 3D printer of FDM wire laminated processing method by converting the CT image into STL file in Open Source DICOM Viewer Osirix. Also, the model of the original shape before damaged was restored and manufactured by Mirror technique based on STL file of not fractured clavicle of the other side by using the symmetry feature of the human body. For the model, the position and size, degree of the fracture was equally printed out. Using the clavicle model directly manufactured with low cost and less time in Department of Radiology is considered to be useful because it can reduce secondary damage during surgery and increase surgery efficiency with Minimal invasive percutaneous plate osteosynthesis(MIPO).

• Journal of the Korean Society of Radiology
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• v.9 no.5
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• pp.269-277
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• 2015

In recent years, concern about the decommissioning of nuclear power plants has been growing according to the nuclear power plants aging. Although site reuse is one of the most important issues in doing decommissioning of nuclear power plants in view of the internal affairs, there is currently no specific standard of the site release criteria for site reuse in the Republic of Korea. In this study, we analyzed the international safety standards for the site release(IAEA's Safety Guide No. WS-G-5.1) and the present domestic condition. Also, we studied the site release criteria and real life examples about advanced countries such as United states and Europe, which already have experience of decommissioning or site release. As a results of the study, we suggested proper standards and future consideration to establish site release criteria. This will be used for preliminary data for establishing the domestic site release criteria after the decommissioning of nuclear power plants.

• Journal of the Korean Society of Radiology
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• v.11 no.6
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• pp.501-508
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• 2017

The dependence of CT scanning parameters on the CT number to physical density conversion from the CT image of CT and CBCT electron density phantom acquired by the CT scanner using in radiotherapy were analyzed by experiment. The CT numbers were independent of the tube current product exposure time, slice thickness, filter of image reconstruction, field of view and volume of phantom. But the CT numbers were dependent on the tube voltage and cross section of phantom. As a result, for physical density range above 0, the maximum CT number difference observed at the tube voltage between 90 and 120 kVp was 27%, and the maximum CT number difference observed between CT body and head electron density phantom was 15%.