• JOURNAL OF ELECTRICAL WORLD
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• no.5 s.149
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• pp.27-30
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• 1989

• Proceedings of the Korean Magnetic Resonance Society Conference
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• 2002.08a
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• pp.40-41
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• 2002

• Journal of radiological science and technology
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• v.11 no.2
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• pp.73-98
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• 1988

• Korean Journal of Radiology
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• v.22 no.6
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• pp.951-958
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• 2021

Objective: To evaluate the usefulness of virtual monochromatic images (VMIs) obtained using dual-layer dual-energy CT (DL-DECT) for evaluating brain tumors. Materials and Methods: This retrospective study included 32 patients with brain tumors who had undergone non-contrast head CT using DL-DECT. Among them, 15 had glioblastoma (GBM), 7 had malignant lymphoma, 5 had high-grade glioma other than GBM, 3 had low-grade glioma, and 2 had metastatic tumors. Conventional polychromatic images and VMIs (40-200 keV at 10 keV intervals) were generated. We compared CT attenuation, image noise, contrast, and contrast-to-noise ratio (CNR) between tumor and white matter (WM) or grey matter (GM) between VMIs showing the highest CNR (optimized VMI) and conventional CT images using the paired t test. Two radiologists subjectively assessed the contrast, margin, noise, artifact, and diagnostic confidence of optimized VMIs and conventional images on a 4-point scale. Results: The image noise of VMIs at all energy levels tested was significantly lower than that of conventional CT images (p < 0.05). The 40-keV VMIs yielded the best CNR. Furthermore, both contrast and CNR between the tumor and WM were significantly higher in the 40 keV images than in the conventional CT images (p < 0.001); however, the contrast and CNR between tumor and GM were not significantly different (p = 0.47 and p = 0.31, respectively). The subjective scores assigned to contrast, margin, and diagnostic confidence were significantly higher for 40 keV images than for conventional CT images (p < 0.01). Conclusion: In head CT for patients with brain tumors, compared with conventional CT images, 40 keV VMIs from DL-DECT yielded superior tumor contrast and diagnostic confidence, especially for brain tumors located in the WM.

• Journal of radiological science and technology
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• v.32 no.1
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• pp.1-15
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• 2009

Newly published IEC 60601-1-3 ; 2008 2nd Edition has two important meanings. First, Radiation Quality and Dose should make sure for safety of patient and staff in manufacturing diagnostic X-ray equipment. Second, it should be minimized of Leakage Radiation, Residual Radiation, and Stray Radiation. The requirement to make enactment or revision of national standard for diagnostic X-ray Equipment is as follows : 1. It should be adjusted the new standard to the recent IEC Publication under the consideration of the Korea medical circumstances. 2. For focus to the Radiation Safety, IEC 60601-1-3 (General requirements for radiation protection in diagnostic X-ray equipment) could be applied to the new regulation. It should be compact sentence. 3. A sudden Notification change should not be desired. It needs a enough time to make easy the circumstances.

• Journal of Korean Medicine for Obesity Research
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• v.18 no.2
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• pp.144-151
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• 2018

Objectives: The purpose of this study is to evaluate the quality of case reports of the Journal of Korean Medicine for Obesity Research by the Case Report (CARE) guidelines. Methods: Case reports published in the Journal of Korean Medicine for Obesity Research from January 2013 to July 2018 were searched from Oriental Medicine Advanced Searching Integrated System (OASIS). We assessed the quality of reporting based on CARE guidelines. Results: A total of 8 case reports were finally included for the assessment. There was a deviation in the sub-item reporting rate by a maximum 75% and a minimum 57.14% in case reports. The 10 sub-items mentioned below, such as 'Timeline', 'Diagnostic challenges', 'Diagnostic reasoning including other diagnoses considered', 'Prognostic characteristics', 'Changes in intervention', 'Important follow-up diagnostic evaluations and other test results', 'Intervention adherence and tolerability', 'Adverse and unanticipated events', 'Patient perspective' and 'Informed consent' were reported below 30%. Conclusions: Efforts to diversify the subject of the case study and to apply appropriate reporting guidelines are needed to improve the quality of the case report contributed to the Journal of Korean Medicine for Obesity Research.

• Journal of radiological science and technology
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• v.20 no.2
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• pp.34-43
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• 1997

There are 4 types of equipment in diagnostic radiography. These are single phase, three phase, inverter type and condenser type X-ray generators. It is very confusing to make an adequate exposure factor and to know the usage of different type of X-ray generators. In this experiment, I explored a comparative study of outputs in 4 different type of X-ray units. I expect that this experiment could be helpful for manufacturer to make both the X-ray equipment better, In terms of Ideal exposure factors, thereby reducing the patient dose. Experimental results are as follow : 1) X-ray output The ratio of X-ray output of single, three phase and inverter type of X-ray generator was 1 : 1.6 : 2 without absorber and 1 : 2 : 2.6 with 20 mm aluminium absorber. 2) Beam quality The X-ray beam quality of single phase generator was proved to be softer than three phase and inverter type of generators by 0.4 mmAL and 0.55 mmAl HVL respectively. 3) Reproducibility Linearity of X-ray output Retroducibility of X-ray output met the regulation below CV 0.05 and linearity also met the regulation below 0.1 in 4 types of diagnostic X-ray generators. 4) The comparison of incident dose Three phase X-ray generator was 20% higher than two other X-ray generators in radiation dose to make same film density.

• Journal of radiological science and technology
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• v.42 no.4
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• pp.285-290
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• 2019

Magnetic resonance imaging is a technique specialized in soft tissue imaging with high contrast resolution without in vivo ionization and has been widely used in various clinical settings. In particular, the recent increase in social stress factors has been used in the diagnosis of pituitary adenoma, the incidence increases rapidly. Recently, due to the development of magnetic resonance imaging, it is possible to diagnose micro pituitary adenoma, but despite the use of contrast medium, there has been a difficulty in diagnosing the pituitary adenoma due to its small size and noise. In order to solve this problem, a proposed method of separating signal components image and noise components image from a measured image is applied, and the improvement of diagnostic efficiency is attempted by removing noise. As a result, it was confirmed that the image quality was improved as a whole by applying SNR for 30 subjects data. It is expected that this study will be useful as a pre-processing method for improving the image quality and developing diagnostic indicators of pituitary adenoma.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.7C
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• pp.671-680
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• 2009

The diagnostic medical images(CT, MRI) in PACS require large storage and long transmission time. A simple and cheap way of overcoming these limitations is to increase the compression ratio. However, this requires a clinical validation for accurate diagnostic applications. The aim of this paper is to improve the compression efficiency of lossless JPEG2000 for diagnostic CT images by performing a visual-Iossless threshold filtering in high frequency subband. A proposed method, based on 5/3 reversible DWT, provides different subband-threshold values according to the compression ratio and gives the high subjective quality to reconstructed diagnostic CT images.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.11
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• pp.1067-1071
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• 2006

Prior to destructive testing, diagnostic tests were performed in ten high voltage motors. Diagnostic tests included polarization infer, ac current, dissipation factor$(tan{\delta})$ and partial discharge magnitude. The rewind of motet slater insulation at rated voltage is assessed by the results of these tests. After completing the diagnostic tests, the stator windings of motors were subjected to gradually increasing ac voltage, until the insulation punctured. No. 8 motor failed near rated voltage of 19.0 kV. The breakdown voltage of No. 4 motet was 7.0 kV which is lower that expected for good quality coils in 6.6 kV class motors. The failure was located in a line-end coil at the exit from the core slot. These two motors began operation in 1994. While testing No. 7 motor, flashover occurred between the stator winding and the stator frame at 15 kV. The relationship between the diagnostic test and the drop in insulation breakdown voltage was analyzed.