• Journal of radiological science and technology
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• v.20 no.2
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• pp.28-33
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• 1997

For the Evaluation of X-ray image intensifier, we measured radiation dose at input of I. I., brightness and fluorescence at output of I. I. by using X-ray exposure meter, optometer and fluorescence meter for the relative conversion factor. Especially, by using fluorescence meter, we could easily get relative conversion factor without having regulated machine by JIS. Since using, the quality of image intensifier is going down. Consequently, it needs continuous quality maintenance.

• Journal of Yeungnam Medical Science
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• v.39 no.4
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• pp.336-340
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• 2022

Although posterior reversible encephalopathy syndrome (PRES) is induced by various causes, a few cases have occurred after severe anemia correction. In this case report, a 45-year-old female patient visited emergency department with a chief complaint of dizziness due to severe anemia related to hypermenorrhea caused by uterine myoma. Before her operation, she had an abrupt headache and seizure during anemia correction with transfusion and injection of gonadotropin-releasing hormone agonist. Immediately after the operation, she experienced visual disturbances, followed by limb weakness and tonic-clonic movements. Magnetic resonance imaging showed alterations in parietal and occipital lobes suggesting cerebrovascular edema with hypoperfusion. Here, we presented and discussed the clinical and radiologic features of PRES related to anemia correction.

• Journal of Radiation Industry
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• v.11 no.1
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• pp.27-31
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• 2017

Reliable follow-up of bone mineral density (BMD) by dual energy X-ray absorptiometry (DXA) is essential in clinical practice. When there is a difference in the BMD values from DXA systems in the same patient, cross calibration equation is required for the reliable follow-up. Unfortunately, no equation is existed in BMD measure between GE Lunar Prodigy Advance (US, GE Healthcare; LPA) and Osteosys Dexxum T (Korea, Osteosys; ODT) DXA systems. In this study, we evaluate the agreement of BMD values between LPA and ODT and suggest the cross calibration equation using European spine phantom (ESP) with two systems. We performed BMD measurements using ten scans with ESP in each DXA systems. We compared BMD values and calculated cross calibration equation by linear regression analysis. The comparison between the LPA and ODT bone densitometers used the ESP. Compared to the ESP BMD values, ODT underestimated 14.36% and LPA overestimated 12.96%. The average of total BMD measurement values acquired with ODT were 21.44% lower than those from LPA. Cross-calibration equation for LPA and ODT was derived from ESP. We calculated simple cross calibration equation for LPA and ODT DXA systems. Cross-calibration equation is necessary for the reliable follow-up of BMD values in two different systems.

• Journal of the Korean Society of Radiology
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• v.15 no.6
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• pp.841-847
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• 2021

Related institutions that use radiation are diverse in Korea, such as research, medical care, and education. Recently, the number of examinations and visits to medical institutions is increasing. As a result, the number of radiological examinations in medical institutions is increasing. Radiation safety management is necessary as well as exposure of radiation workers. For safety management, first of all, it is necessary to wear the personal exposure dosimeter correctly and measure it accurately after wearing it. This study tries to evaluate and verify the measurement straightness of PLD devices by radiation of a diagnostic generator. Radiation division irradiation time interval was measured after irradiating 10 times at 10, 30, and 60 sec and irradiating the irradiation distance from 30 to 100 cm at 10 cm intervals to measure the change in absorbed dose depending on the distance. As a result, there was no difference in absorbed dose by time interval. This is considered to be helpful in various studies by using a diagnostic generator for the study of high absorbed dose.

• Korean Journal of Radiology
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• v.22 no.2
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• pp.225-232
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• 2021

Objective: To determine whether changes in the transiting nerve rootlet or its surroundings, as seen on MRI performed after lumbar hemilaminectomy, are associated with persistent postoperative pain (PPP), commonly known as the failed back surgery syndrome. Materials and Methods: Seventy-three patients (mean age, 61 years; 43 males and 30 females) who underwent single-level partial hemilaminectomy of the lumbar spine without postoperative complications or other level spinal abnormalities between January 2010 and December 2018 were enrolled. Two musculoskeletal radiologists evaluated transiting nerve rootlet abnormalities (thickening, signal alteration, distinction, and displacement), epidural fibrosis, and intrathecal arachnoiditis on MRI obtained one year after the operations. A spine surgeon blinded to the radiologic findings evaluated each patient for PPP. Univariable and multivariable analyses were used to evaluate the association between the MRI findings and PPP. Results: The presence of transiting nerve rootlet thickening, signal alteration, and ill-distinction was significantly different between the patients with PPP and those without, for both readers (p ≤ 0.020). Conversely, the presence of transiting nerve rootlet displacement, epidural fibrosis, and intrathecal arachnoiditis was not significantly different between the two groups (p ≥ 0.128). Among the above radiologic findings, transiting nerve rootlet thickening and signal alteration were the most significant findings in the multivariable analyses (p ≤ 0.009). Conclusion: On MRI, PPP was associated with transiting nerve rootlet abnormalities, including thickening, signal alterations, and ill-distinction, but was not associated with epidural fibrosis or intrathecal arachnoiditis. The most relevant findings were the nerve rootlet thickening and signal alteration.

• Journal of radiological science and technology
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• v.29 no.3
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• pp.197-210
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• 2006

This study explored several agenda related to license system, education, professional work of radiological technologists(RTs) and a transition process of law for them to investigate a developmental strategy of RTs as a professional career. The results are as followings : 1. The national license system for RTs was started from 1965, 1965-1972 x-ray technicians(medical assistance), 1973-present(2006) radiotechnologist(medical technologist) since then. 2. The average pass ratio of national license examination(1965-2006) for RTs was 46.6%. The method, subjects and level of the examination should be improved. 3. The education term for RTs has been changed since 1963 ; 1963-1990 two year college, 1991-1999 three year college, 2000-2006 four year and three year college depending on universities and colleges. As of 2006, there are twelve 4-year universities and eighteen 3-year colleges. The total number of new students were 1,956. 4. The new developmental paradigm should be made for technology education of RTs corresponding to the development of medicine and science. 5. The qualification system of clinical specialists in radio-technology field needs to be operated not by the non-governmental body(The Korean Radiological Technologists Association) but by the governmental body. 6. The vertical relationship among RTs, doctors and other medical workers should be rebuilt through the revision of law. Especially, doctors and dentists 'guidance authority' for RTs should be changed to 'request authority'. 7. The service extent of RTs should be extended in medical fields corresponding to professional work of RTs and a revision of the law needed for this situation.

• Journal of radiological science and technology
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• v.32 no.4
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• pp.453-460
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• 2009

The purpose of this study was to determine the dose distribution and image quality according to slice thickness and BC(beam collimation) in the gantry aperture. CT scans were performed with a 64-slice MDCT(Brilliance 64, Philips, Cleveland, USA) scanner. To determine the dose distribution according to BC, a ionization chamber was placed at isocenter and 5, 10, 15, 20, 25 and 30 cm positions from the isocenter in the 12, 3, 6 and 9 o'clock directions. The dose distribution for phantom scan was also measured using CT head and body dose phantom with five holes at the center of the phantom and the positions of the 12, 3, 6 and 9 o'clock directions. The image noise measurement for different BCs was performed using an AAPM CT phantom. Water-filled block of the phantom was moved by 5 cm or 10 cm to the 12 o'clock direction, and the image noise was measured at the center of the phantom, and the points of 12, 3, 6 and 9 o'clock direction respectively. Some points were placed beyond the scan field of view (SFOV), so that measurement was not possible at that points. The results are as follows: The CTDIw showed a larger decrease as the source goes farther from the iso-center or the BC became wider. The CTDIw depends on the BC width more than the number of the channel of a detector array. The value of CTDIW decreased with increasing BC, but the value decreased 16.6~31.9% in the head phantom scan in air scan and 51.0~64.5% in the body phantom scan. The value of the noise was 3.9~5.9 in the head and 5.3~7.4 in the body except for BC of $2{\times}0.5\;mm$, regardless of the degree of deviation from the iso-center. When a subject was located within the SFOV, the position did not significantly affect image quality even if the subject was out of the center.

• Progress in Medical Physics
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• v.24 no.1
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• pp.61-67
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• 2013

In this study, we developed and evaluated the patient respiration training method which can help to avoid the problems for the limitation of RGRT applicable patient cases. By using the MEMS (micro-electro-mechanical-system) acceleration sensor, we measured movement of motion phantom. We had compared the response of MEMS with commercially introduced real time patient monitoring (RPM) system. We measured the response of the MEMS with 1 dimensional motion phantom movement for 2.5, 3.0, 3.5 second of period and the 2.0, 3.0, 4.0 cm of the amplitudes. The measured period error of the MEMS system was 0.6~6.0% compared with measured period using RPM system. We found that the shape of MEMS signals were similar with RPM system. From this study, we found the possibility of MEMS as patient training system.

• Journal of radiological science and technology
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• v.30 no.3
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• pp.251-257
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• 2007

Medical imaging zero-phase-sequence component in estimation for picture that is gotten that importance weight of digital device is increased day by day at the same time also so much important. Special quality about resolution uses Modulation Transfer Function by representative method to evaluate sharpness on important element in image quality. Get MTF converting slit, differentiating this making composition ESF edge method uses Excel by edge method in this study to be composition LSF get in fourier to informed measuring mean universally. Such method is considered that can help in principle grasping of step before make Program using C language as many as Matlab.

• Journal of radiological science and technology
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• v.31 no.3
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• pp.217-222
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• 2008

Radiation dose to radiologists working at three hospitals in Seoul was investigated from Jan 1, 2006 to Dec. 31, 2006. The results are as follows. First, radiation dose to radiologists at a cardiac angiography room was measured as 1.41mSv, the highest while radiation dose to radiologists at a department of radiation oncology was measured as 0.64 mSv, the lowest. Second, radiation dose proves to be in direct proportion to the number of X-ray treatment. Third, as for the radiation dose in X-ray treatments, radiologists in cardiac angiography room are exposed to the largest amount of radiation while radiologists in diagnostic radiology department are exposed to the smallest amount of radiation. Last, radiation dose at a cardiac angiography room is the largest and is followed by nuclear medicine, diagnostic radiology, and radiation oncology departments in order. According to ICRP, exposure less than 20mSv per year is highly recommended while radiation dose is allowed as long as it is ranged less than 50mSv per year or 100mSv within a 5-year period. Taking into account the results, radiation exposure does not do any harm to radiologists at any related departments in Korean hospitals because the dose per year is less than 1.60mSv.