• Journal of radiological science and technology
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• v.23 no.2
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• pp.39-42
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• 2000

When ordinary sugar is exposed to ionizing radiation, a number of free radical are created in sugar, and Electron Paramagnetic Resonance (EPR) signal appears from the sugar because of the paramagnetic property of free radical. In this paper, EPR signal intensity has been measured in x-ray irradiated sugar for various absorbed doses, irradiated dose up to 50 Gy. The EPR intensity signals are increased as the x-ray irradiation increases. Also, the fading value decreased to about 3% in 30day after the irradiation. Therefore, the sugar is a useful material for emergency dosimeter as the free radical dosimetry with the EPR equipment.

• Korean Journal of Radiology
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• v.21 no.7
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• pp.851-858
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• 2020

Coronavirus disease 2019 (COVID-19) is a new infectious disease rapidly spreading around the world, raising global public health concerns. Radiological examinations play a crucial role in the early diagnosis and follow-up of COVID-19. Cross infection among patients and radiographers can occur in radiology departments due to the close and frequent contact of radiographers with confirmed or potentially infected patients in a relatively confined room during radiological workflow. This article outlines our experience in the emergency management procedure and infection control of the radiology department during the COVID-19 outbreak.

• Journal of radiological science and technology
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• v.33 no.2
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• pp.93-96
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• 2010

This study evaluates usefulness of the developed assistant device by taking projection of patellofemoral joint in emergency patients who were doubt posterior cruciate ligament injury in knee joint. The subjects of experiment were patients who visited Eul-Ji University Hospital due to knee injury from January 2006 to December 2006. Seventeen patients, who took the Knee post stress view, Knee merchant view, Knee Seo's view to use assistant device and Knee MRI. To make assistant device of $170{\times}50{\times}70\;cm$, we evaluated its usefulness by measuring posterior dislocation of tibia. Seo's view is more accurate to make judgment of posterior cruciate ligament injury than original knee post stress view. Interval difference of posterior dislocation of original knee post stress view is $6.17{\pm}3.04$ and Seo's view is $8.74{\pm}4.47$. The results show injury of patellofemoral joint, vertical fracture of patella and posterior cruciate ligament injury by taking a projection using Seo's view. Therefore, it is useful to take projection earlier than talometer and MRI in emergency patients who were doubt posterior cruciate ligament injury in knee joint.

• Journal of radiological science and technology
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• v.39 no.3
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• pp.451-459
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• 2016

The development of radioprotector is being actively conducted in order to reduce the damage from over radiation exposure at radiation accident or radiation therapy. So this study was confirmed for radiation protective effects using the Cynanchi wilfordii Radix that has been known to be effective for antioxidant activity, anti-cancer, immune enhancing effects. The method of this study was administered orally Cynanchi wilfordii Radix ethanol extracts to Sprague Dawley Rat(SD Rat) for 14 days once a day, while measuring changed blood cell, spleen index, liver and uterus tissue along the change in time of 1, 4, 7 and 21 days after X-ray beam of 7 Gy irradiation. As the result of the experiment, the experimental group's rats which are administered with Cynanchi Wilfordii Radix ethanol extracts showed a rapid recovery in white blood cell count(p < 0.05) and spleen index(p < 0.05). In addition, condensation of nuclei, cytoplasmic swelling, and inflammatory cell infiltration in experimental group's liver cell was decreased more than in irradiation group's component. Further, experimental group's Uterine gland decreased the apoptosis more than irradiation group's components did. It is expected that Cynanchi Wilfordii Radix extracts will be useful as a new radioprotector. With above in mind, this paper may provide appropriate implications with the field of emergency management such as radiation accident.

• Journal of radiological science and technology
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• v.40 no.4
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• pp.639-646
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• 2017

The purpose of this study is to present the algorithm to minimize the image noise caused by deterioration of high X-ray container inspection equipment and the faulty detection sensors, and to improvement quality of the container inspection images using MATLAB Toolbox. The daily checking images for the container inspection were used with the subject images and the noise caused by the horizontal and vertical images was evaluated with Root Mean Square (RMS) method, which is the most basic evaluation method of digital radiation image. Also, quality of the improved images was evaluated compared to quality of the orignal images. As a result, all RMS value of the improved images was lower then the original images by a mean of 13.5% in the horizontal images and 18.2% in the vertical images respectively. Also so did RMS value of the improved container images, by a mean of 13.4% in the horizontal images and 19.1% in the vertical images respectively. These findings can be verified objectively and visually and they would help the reading process of the container images be effective in Korea Customs Service.

• Journal of Korean Neurosurgical Society
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• v.29 no.8
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• pp.1050-1054
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• 2000

Objective : The incidence of head injury has been increasing in the rural area. The author investigated the clinical features and difficulties in care of the acute head-injured patients in this area. Method and Material : The authors performed a retrospective review of radiological data and clinical records in patients with mild to moderate head injury. Cause, type of craniocerebral injury, delayed intracranial lesions, complications, its relation to alcohol abuse, and outcome were analyzed. Results : In total of 68 cases, 20(29.4%) victims were associated with acute alcohol intoxication. Motor vehicle accident was the leading cause of head injury and the most common craniocerebral lesion was basilar skull fracture. Eight(11.8%) patients showed delayed radiological and clinical deterioration and 40(58.8%) were followed-up regularly after discharge. The subdural hygroma was commonly noted in the elderly and alcoholics. Causes of thirty events that resulted in an atypical and difficult neurosurgical practice were as follows : delayed admission, premature discharge against doctor's request, refusal of radiological studies and admission, misunderstanding of disease entity, and unreasonable desire of transfer to tertiary hospitals. Inaccurate initial diagnoses were made by emergency doctors in twenty patients. During the course of treatment, there were a few complications such as alcohol withdrawal, acute otitis media, cerebrospinal fistula, facial weakness, and posttraumatic seizure. Outcome was good in 60(88.2%) patients. Conclusion : Most of minor head trauma patients in this series have shown good results, but we have to consider some possible complications and delayed intracranial lesions in these patients that should be managed with special cautions with various kinds of treatment difficulties.

• Journal of radiological science and technology
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• v.44 no.6
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• pp.615-621
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• 2021

In the medical field, radiation provides information for the diagnosis and treatment of diseases. As the use of radiation increases and the risk of exposure increases, interest in radiation protection is also rapidly increasing. Lead shielding material is mainly used, which has a risk of lead poisoning and absorption into the body. Tungsten mixed filament shielding sheets were fabricated with a size of 70 × 70 mm and a thickness of 1, 2, and 4 mm by using a 3D printer. In the general shooting experiment, the thickness of the shielding sheet is 1 ~ 5mm, the tube voltage is 60, 80, 100, 120 kVp and the tube current is 20, 40 mAs. In general photography, Tungsten showed better shielding rate compared to Brass, Copper, and Lead protective tools under all irradiation conditions, and in particular, Tungsten 5 mm showed 100% shielding rate. The 3D-printed tungsten mixed filament shielding is expected to be used as a new shield that can replace the existing lead protection tools as it shows a better shielding rate than the existing lead protection tools in Radiography.

• Progress in Medical Physics
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• v.32 no.4
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• pp.145-152
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• 2021

Purpose: During the treatments of cancer patients with a linear accelerator (LINAC) using photon beams with energies ≥8 MV, the components inside the LINAC head get activated through the interaction of photonuclear reaction (γ, n) and neutron capture (n, γ). We used spectroscopy and measured the dose rate for the LINAC in operation after the treatment ended. Methods: We performed spectroscopy and dose rate measurements for three units of LINACs with a portable high-purity Germanium (HPGe) detector and a survey meter. The spectra were obtained after the beams were turned off. Spectroscopy was conducted for 3,600 seconds, and the dose rate was measured three times. We identified the radionuclides for each LINAC. Results: According to gamma spectroscopy results, most of the nuclides were short-lived radionuclides with half-lives of 100 days, except for ⁶⁰Co, ⁶⁵Zn, and ¹⁸¹W nuclides. The dose rate for three LINACs obtained immediately in front of the crosshair was in the range of 0.113 to 0.129 µSv/h. The maximum and minimum dose rates measured on weekends were 0.097 µSv/h and 0.092 µSv/h, respectively. Compared with the differences in weekday data, there was no significant difference between the data measured on Saturday and Sunday. Conclusions: Most of the detected radionuclides had half-lives <100 days, and the dose rate decreased rapidly. For equipment that primarily used energies ≤10 MV, when the equipment was transferred after at least 10 minutes after shutting it down, it is expected that there will be little effect on the workers' exposure.

• The korean journal of orthodontics
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• v.52 no.2
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• pp.123-130
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• 2022

Objective: To evaluate if a remote digital monitoring system added at the end of orthodontic treatment could positively influence the retention phase by reducing the occurrence of misfit of removable appliances, number of emergency appointments (EA), and orthodontic relapse. Methods: Twenty-seven patients who completed active orthodontic treatment were divided into the study and control groups. In addition to the standard chairside follow-up appointments at month 1 (T1), month 3 (T2), month 6 (T3), the study group patients were monitored using Dental Monitoring^® with monthly intra-oral scans. Occurrence of misfit of removable retainers, number of EAs, and intercanine width change were recorded for both groups. Differences in EAs and retainer fit were assessed using the chi-square test. Intra-group and inter-group differences in the intercanine width were assessed with Friedman test and Mann-Whitney U test, respectively (α = 0.05). Results: The study group showed a significantly lower occurrence of misfit of removable retainers (p = 0.027) compared to the control group. No significant inter- and intra-group difference was found in the EAs and intercanine width change at each time-point. Conclusions: Integrating remote monitoring systems, such as Dental Monitoring^®, to the retention phase of the orthodontic treatment may lower the occurrence of misfit of removable retainers. However, a small sample size and a short observation period limit the strength of this evidence. These preliminary results tentatively suggest that remote monitoring technologies may be beneficial, especially during the COVID-19 pandemic, when the regularity of in-office visits might be disrupted.

• Korean Journal of Radiology
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• v.23 no.1
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• pp.124-138
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• 2022

Gastrointestinal (GI) emergencies in neonates and infants encompass from the beginning to the end of the GI tract. Both congenital and acquired conditions can cause various GI emergencies in neonates and infants. Given the overlapping or nonspecific clinical findings of many different neonatal and infantile GI emergencies and the unique characteristics of this age group, appropriate imaging is key to accurate and timely diagnosis while avoiding unnecessary radiation hazard and medical costs. In this paper, we discuss the radiological findings of essential neonatal and infantile GI emergencies, including esophageal atresia and tracheoesophageal fistula, hypertrophic pyloric stenosis, duodenal atresia, malrotation, midgut volvulus for upper GI emergencies, and jejunoileal atresia, meconium ileus, meconium plug syndrome, meconium peritonitis, Hirschsprung disease, anorectal malformation, necrotizing enterocolitis, and intussusception for lower GI emergencies.