• Korean Journal of Radiology
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• v.21 no.8
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• pp.987-997
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• 2020

Objective: Measurement of the liver and spleen volumes has clinical implications. Although computed tomography (CT) volumetry is considered to be the most reliable noninvasive method for liver and spleen volume measurement, it has limited application in clinical practice due to its time-consuming segmentation process. We aimed to develop and validate a deep learning algorithm (DLA) for fully automated liver and spleen segmentation using portal venous phase CT images in various liver conditions. Materials and Methods: A DLA for liver and spleen segmentation was trained using a development dataset of portal venous CT images from 813 patients. Performance of the DLA was evaluated in two separate test datasets: dataset-1 which included 150 CT examinations in patients with various liver conditions (i.e., healthy liver, fatty liver, chronic liver disease, cirrhosis, and post-hepatectomy) and dataset-2 which included 50 pairs of CT examinations performed at ours and other institutions. The performance of the DLA was evaluated using the dice similarity score (DSS) for segmentation and Bland-Altman 95% limits of agreement (LOA) for measurement of the volumetric indices, which was compared with that of ground truth manual segmentation. Results: In test dataset-1, the DLA achieved a mean DSS of 0.973 and 0.974 for liver and spleen segmentation, respectively, with no significant difference in DSS across different liver conditions (p = 0.60 and 0.26 for the liver and spleen, respectively). For the measurement of volumetric indices, the Bland-Altman 95% LOA was -0.17 ± 3.07% for liver volume and -0.56 ± 3.78% for spleen volume. In test dataset-2, DLA performance using CT images obtained at outside institutions and our institution was comparable for liver (DSS, 0.982 vs. 0.983; p = 0.28) and spleen (DSS, 0.969 vs. 0.968; p = 0.41) segmentation. Conclusion: The DLA enabled highly accurate segmentation and volume measurement of the liver and spleen using portal venous phase CT images of patients with various liver conditions.

• Journal of Yeungnam Medical Science
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• v.21 no.2
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• pp.167-176
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• 2004

Background: Electromagnetic fields (EMF) are ubiquitous in modern society including medical field. As the technology of medical instruments and telecommunications has developed rapidly, it has influenced on our lives in many ways. Modern medical practice requires high quality medical equipments, which have a great deal of electromagnetic interference and susceptibility. The purpose of this study were to evaluate electromagnetic condition under usual clinical condition and to suggest a practical guideline in general hospital. Materials and Methods: The actual state of the electromagnetic interference in the medical field was studied under usual clinical conditions including operating rooms, intensive care units, magnetic resonance imaging unit, and hyperthermia unit. Results: There was considerable noise as a result of electromagnetic fields from medical equipments including electrosurgical units and hyperthermia unit, and cellular phones, which could induce serious functional derangements of functioning medical devices. Conclusion: It will be necessary to evaluate the individual electromagnetic situations under various medical conditions and to define a limited zone for cellular phone as well as reposition medical equipments to secure a safer medical practice and to minimize electromagnetic interference.

• Journal of Korean society of Dental Hygiene
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• v.17 no.6
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• pp.1067-1080
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• 2017

Objectives: This study analyzed the perception towards clinical practice education content held by dental hygiene students in dental institutions and their perceived importance of dental hygienists' clinical duties. Methods: The subjects of this study were 182 dental hygienists who were working at dental institutions in Seoul, Gyeonggi, and Chungcheong areas. A survey was conducted with a self-administered questionnaire. In the questionnaire, the clinical practice contents were classified into observation, preparation, and performance, and the importance of clinical duty was measured with a 3-point scale. For the clinical practice contents and the importance of duty, descriptive statistics and chi-square test were performed, and the study results were analyzed using STATA 11.0. Results: With regard to clinical practice contents, observation was mainly performed in oral & maxillofacilal radiology, preventive dentistry, periodontal medicine and oral medicine. In primary care and infection control, practice and observation were mainly performed. In the department of orthodontics and pediatric dentistry, observation and preparation were mainly conducted, while in oral surgery, conservative dentistry observation, preparation and practice were all conducted. With regard to clinical practice contents according to the dental institution, there were statistically significant differences in the type of dental institution and the duty (p>0.05). In terms of the importance of dental hygienist's duty, infection control, toothbrushing education for each patient, removal of plaque, and patient education after surgery were considered important. Conclusions: For clinical practice of the dental hygiene department, the education contents should be standardized in accordance with the importance of the dental hygienist's duty, a protocol for operation of practice should be developed, and a method of standardization of evaluation should be sought in the future.

• Journal of Korean society of Dental Hygiene
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• v.14 no.2
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• pp.131-137
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• 2014

Objectives : The aim of the study is to investigate anxiety, fatigue and stress of dental hygiene students in clinical practice and to improve the psychological support program. Methods : A self-reported questionnaire was filled out by 428 dental hygiene students in 4 universities in Gwagju and Jeonnam. Data were analyzed for anxiety, stress and fatigue, general characteristics using SPSS 18.0 program for descriptive statistics, ANOVA, and correlation. Results : Saliva suction showed the most high score in treatment($mean{\pm}SD=2.92{\pm}1.13$) and was followed by children dental care($2.79{\pm}1.21$), preventive dental care($2.38{\pm}1.04$), maxillofacial radiology($2.35{\pm}1.15$). During the clinical practice, students felt uneasy when they stayed in relative home(p<0.05). Poor interpersonal relation(p<0.001), poor health condition(p<0.01), low satisfaction with major(p<0.01), the other cause of major choice(p<0.01) influenced on their stress. Satisfaction with major was closely related to clinical practice performance, anxiety, physical fatigue and mental fatigue. Conclusions : In order to reduce physical, mental, neuro sensory fatigue of students in clinical practice, it is recommended to reinforce the patient care etiquettes in curricula.

• Journal of Korean society of Dental Hygiene
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• v.22 no.5
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• pp.323-332
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• 2022

Objectives: This study aims to confirm the educational necessity and utilization of VR media. And it was conducted to prepare basic data necessary for the use of VR in various dental hygiene education in the future and the development of innovative practical training courses. Methods: Before and after using VR in oral radiology practice classes, learning interest (4 items), learning commitment (9 items), learning motivation (5 items), educational media preference (4 items), and satisfaction (10 items) were investigated and analyzed. Friedman two way ANOVA by ran a nonparametric analysis corresponding to repeated measures ANOVA was performed. The statistical significance level was 0.05. Results: It was found that there were statistically significant differences in learning interest, learning immersion, and learning motivation according to the type of oral radiology practice education medium (p<0.05). Conclusions: VR is expected that the use of learning media using VR will lead to students' interest, immersion, and learning motivation in class, and that positive learning effects on VR education media can be sufficiently obtained.

• The Korean Society of Law and Medicine
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• v.24 no.1
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• pp.3-42
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• 2023

The Supreme Court en banc decision on December 12, 2022 (docket number 2016Do21314) ruled that the diagnosis of endometrial hyperplasia by an oriental medical doctor using a diagnostic ultrasound device was not an unlicensed medical practice for an oriental medical doctor, which shall be scrutinized by the article 27 (1) of the Korean Medical Service Act. This ruling did not determine that a specific medical practice, especially diagnosis, based on the radiology, which is a part of western medicine, was not an unlicensed medical practice for an oriental medical doctor. Rather, it intended to clarify that the prosecutor should specify and prove the way of diagnosis and he should not prosecute mere the use of a diagnostic ultrasound device itself. To that extent, the ruling is agreeable because, as the oriental medicine community has argued, there is no regulation prohibiting the use of certain devices. It is probable, however, that the way of diagnosis established in radiology, which is a part of western medicine, was actually used in the case. In that case, there is undeniably an unlicensed medical practice for an oriental medical doctor. While many of the cases where the demarcation between (western) medicine and oriental medicine have been problematized thus far have been experimental treatment in nature, the above practice of using ultrasound appears to be frequently done in many oriental clinics, and so it is necessary to cope with the possibility of a disguised unlicensed medical practice. Another problem is the prevention of unfair practice or the protection of medical consumers. In fact, many oriental medical clinics' practice appear to have a tendency of inducing medical consumers' misunderstanding that a diagnosis based on radiology, which is a part of western medicine, were provided. It is hard to respond to this problem with demarcation between (western) medicine and oriental medicine. A new regulation against unfair practice might be necessary to implement.

• Journal of the Korean Society of Radiology
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• v.14 no.6
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• pp.827-832
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• 2020

X-ray equipment, which is frequently used in radiology and treatment, is the most common and most used equipment in clinical practice. Equipment must provide accurate information to patients through continuous quality control. In case of manual quality control measurement, reproducibility may be poor and there may be a problem with reliability of evaluation results. In this study, an automated program was developed and attempted to measure how much the central ray between the focus of the X-ray tube and the variable aperture of the diagnostic X-ray generator used in clinical practice coincides. As a result of the experiment, it succeeded in calculating the coordinates of the two center points, and the distance between the two points was calculated in pixels and applied to the judgment and the automatic judgment value for whether the center line coincidence is within the normal angle or the abnormal angle is presented. The results of this study are considered to be very helpful in the quality control of the X-ray apparatus.

• Journal of radiological science and technology
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• v.16 no.1
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• pp.89-94
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• 1993

However, technical advances in ultrasono imaging have had a remarkable impact on the study of biliary system oral cholecystography is a contrast of the gallbladder which is very frequently performed even with the application of Extra Shock Wave Lithotripsy(ESWL) in clinical use. Oral GB requires a stringent preparation if it is to be fully successful and a considerable amount of time to complete all its procedures and its objects of the radiographs. 1) to obtain a firm diagnosis of the presence of gallstones. 2) to essess function of the gallbladder that is, its ability to concentrate and store bile. After a times sequence of X-ray exposures taken in various positions to show the gallbladder to be satisfactorily filled, the patient is given a fatty meal, for instances two eggs or a cup of milk. The gallbladder which is drained by the cystic duct stores and concentrates the bile and is stimulated to contrast and excrete the bile by hormone "cholecystokinin" secreted in the intestinal mucosa. To evaluate the effect of the fatty meal which caused the gallbladder to constrict and empty, and by so doing the contrast medium passes through the cystic and bile ducts which are shown in radiographs exposed from 15-30 minutes after the variety practice of fattymeal, such as soft-boiled 2 eggs, raw 2 eggs, 100g of peanuts, and 200ml of milk. If the concentration of the opaque medium in the gallbladder is adequate, then not only the size, shape and position of the gallbladder will be shown from firms taken at intervals, the rate of concentration of the opaque medium and of the emptying of gallbladder has been measured and analyzed.

• Imaging Science in Dentistry
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• v.38 no.1
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• pp.7-15
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• 2008

Purpose: This study provides comparative measurements of absorbed and effective doses for newly developed cone beam computed tomography (CT) in comparison with these doses for conventional CT. Materials and Methods: Thermoluminescent dosimeter rods (TLD rod: GR-200, Thermo Fisher Scientific Inc., Waltham, MA, USA) were placed at 25 sites throughout the layers of Male ART Head and Neck Phantom (Radiology Support Devices Inc., Long Beach, USA) for dosimetry. Implagraphy, DCT Pro (Vatech Co., Hwasung, Korea) units, SCT-6800TXL (Shimadzu Corp., Kyoto, Japan), and Crane x 3+(Soredex Orion Corp., Helsinki, Finland) were used for radiation exposures. Absorption doses were measured with Harshaw 3500TLD reader (Thermo Fisher Scientific Inc., Waltham, MA, USA). Radiation weighted doses and effective doses were measured and calculated by 2005 ICRP tissue weighting factors. Results: Absorbed doses in Rt. submandibular gland were 110.57 mGy for SCT 6800TXL (Implant), 24.56 mGy for SCT 6800TXL (3D), 22.39 mGy for Implagraphy 3, 7.19 mGy for DCT Pro, 5.96 mGy for Implagraphy 1, 0.70 mGy for Cranex 3+. Effective doses $(E_{2005draft)$ were 2.551 mSv for SCT 6800TXL (Implant), 1.272 mSv for SCT 6800TXL (3D), 0.598 mSv for Implagraphy 3, 0.428 mSv for DCT Pro and 0.146 mSv for Implagraphy 1. These are 108.6, 54.1, 25.5, 18.2 and 6.2 times greater than panoramic examination (Cranex 3+) doses (0.023mSv). Conclusion: Cone beam CT machines recently developed in Korea, showed lower effective doses than conventional CT. Cone beam CT provides a lower dose and cost alternative to conventional CT, promising to revolutionize the practice of oral and maxillofacial radiology.

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.459-464
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• 2023

Due to the development of advanced technology, a lot of digital radiographic equipment has been developed, which is very helpful for accurate diagnosis and treatment, and it is very important to train personnel who have acquired professional knowledge in order to use it safely and effectively. Students are exposed to the risk of radiation exposure in radiography training using diagnostic X-ray equipment, and some educational institutions do not use X-ray equipment due to management difficulties in accordance with the Nuclear Safety Act. As a solution to this, this study developed a medical radiation simulator for education that does not generate radiation by using a vision sensor and self-developed software. Through this, educational institutions can reduce the burden of administrative implementation according to the law, and students can obtain a high level of educational effects in a healthy practice environment without radiation exposure.