• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.667-674
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• 2019

Because examination with technegas produces images through simple diffusion accumulation, the examination room can become contaminated after scan. Therefore, radiation workers and patients awaiting examination will be affected by internal exposure from technegas inhalation. Before and after gravity ventilation, I am trying to find a way to reduce the exposure dose of waiting patients according to a comparative analysis of horizontal spatial dose rates over time. Spatial dose ratio were measured for 10 minutes from various distances and angles around ventilator's location before and after gravity ventilation. Then, mean values, standard deviation and reduction ratio were calculated. The highest reduction rate of gravity ventilation was 95.31% and the highest reduction ratio was 1 to 3 minutes. Therefore, the gravity ventilation could reduce the exposure dose of radiologic technologists, waiting patients, patient guardians and nurses. In conclusion, the reduction of the exposure dose during the technegas ventilation study through gravity ventilation will play a role in optimiging the protection and it is in accordance with the recommended reduction of the medical exposure by ICRP 103.

• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.637-643
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• 2019

To verify internal movements of the body, a DICOM file obtained from CT and a Geant4 code were used to simulate lung cancer patients. In addition, the method is applied to measure the movement of tumor when the movement of t he tumor is located inhale and exhale by creating a virtual tumor in the self-produced moving phantom, and to check the distribution of dose in the treatment plan and the accuracy of tumor in PTV for respiratory and lung cancer patients. It was confirmed that 97% or more respiratory control radiation therapy was effective even if the moving area was more than 3cm, in the 40% to 70% range. Dose distribution with respiratory radiation therapy applied to moving targets, measured by film in the actuation phantom, was shown to be within a 3mm margin of error for dose distribution containing 90%. It was confirmed that for actual patient breathing curves, the treatment time may be shorter than that due to the longer expiratory time.

• Journal of the Korean Society of Radiology
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• v.13 no.1
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• pp.73-80
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• 2019

Neutrons are generated by the nuclear reaction, which is absorbed into the concrete wall and causes the activation during cyclotron operation. The purpose of this study is to investigate the effect of neutron activation and radiative concrete on concrete type. This experiment used Monte Carlo simulation and RESRAD model. The results of the experiment showed that the higher the content of Fe in concrete, the greater the shielding rate. The effect of $^{56}Fe(n,\;2np)^{54}Mn$ reaction on workers is also increased. However, radioactive nuclides have low activity and have very low impact on workers. Radioactive concrete should be treated as general wastes with less than its self-disposal tolerance level, and it should be recycled to the surface such as road repair rather than landfill to minimize the effect of $^{14}C$.

• Journal of the Korean Society of Radiology
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• v.14 no.7
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• pp.931-936
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• 2020

This study was conducted to observe the changes in radiation exposure dose and image quality of pediatric patients according to the presence and size of the gonadal shield when using the AEC system. X-ray equipment was used to measure the radiation exposure dose in the abdominal and gonads of the pediatric phantom when no shielding body was used and when three different sizes of shielding body were used, and SNR and CNR were measured through the obtained images. As a result of the study, the radiation exposure dose to the gonads decreased in proportion to the size of the radiation shield, but the radiation exposure dose to the abdomen was rather increased, and the image quality did not change. It is recommended to use a shield with a size optimized for the age, weight, and body size of the pediatric patient so as not to be overexposed by the increased radiation due to the radiation shield due to the use of the AEC System. For this purpose, information about the pediatric patient with the nurse It is believed that exchange is necessary.

• Journal of the Korean Society of Radiology
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• v.15 no.4
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• pp.533-538
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• 2021

^99mTcO₄^- is used to measure thyroid uptake. When measuring background radioactivity of the thigh, the distance between the detector and the thigh was 20 cm at a position 10 cm above the knee from the knee to the pelvis. At 25 cm, many hospitals are measuring at different distances. The purpose of this study was to study the difference in effectiveness in obtaining the thyroid uptake rate by quantitatively analyzing the uptake rate measurement at two distances. As a result, the average thyroid uptake rate measured at 20 cm in the thigh of 50 patients was 3.532±4.312%, and the average thyroid uptake rate measured at 25 cm was 3.680±4.304%. As a result of the thyroid uptake rate test result, the femoral background radioactivity value measured at a distance of 20 cm was relatively higher than the background radioactivity value measured at a distance of 25 cm, and as a result, the thyroid uptake rate was 0.148% lower.

• Imaging Science in Dentistry
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• v.51 no.4
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• pp.383-388
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• 2021

Purpose: The aim of this study was to evaluate the root canal morphology of mesial roots of mandibular first molars. Materials and Methods: Forty extracted mandibular first molars were used in this study. The morphological examination of root canals was conducted in accordance with the Vertucci classification using micro-computed tomography (micro-CT). Any aberrant root canal configurations not included in the Vertucci classification were recorded, and their frequency was established using descriptive statistics. Intra-observer reliability was assessed using the Wilcoxon signed-rank test, while inter-observer reliability was assessed using the Cohen kappa test. Significance was evaluated at the P<0.05 level. Results: The mesial roots of mandibular first molars had canal configurations of type I (15%), type II (7.5%), type III (25%), type IV (10%), type V (2.5%), type VI (7.5%), and type VII (7.5%). The images showed 10 (25%) additional configuration types that were not included in the Vertucci classification. These types were 1-3-2-3, 1-2-3-2-3, 2-3-1, 2-3, 1-2-3-1, 2-1-2-3, 3-2-1, 1-2-3-1, 2-3-2-3, and 1-2-1-2-1. The intra-observer differences were not statistically significant(P>0.05) and the kappa value for inter-observer agreement was found to be 0.957. Conclusion: Frequent variations were detected in mesial roots of mandibular first molars. Clinicians should take into consideration the complex structure of the root canal morphology before commencing root canal treatment procedures to prevent iatrogenic complications. Micro-CT was a highly suitable method to provide accurate 3-dimensional visualizations of root canal morphology.

• Journal of the Korean Chemical Society
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• v.66 no.2
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• pp.92-95
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• 2022

Failure Renal is the function of the kidneys to remove waste products and keep them on the periphery. and minerals for the body. Chronic renal failure is a syndrome characterized by a slow, irreversible deterioration of renal function due to the slow destruction of renal parenchyma. Calcium is one of the important minerals that the body contains in the blood and important tissues, and it has an important role in vital processes such as muscle contraction, nerve impulse conduction, the efficiency of heart muscle work, and blood clotting processes. The aim of the study is to study and compare calcium levels in men and women. It includes studying abnormal levels of calcium that cause many diseases, including chronic renal failure, and studying changes associated with renal failure. The method of this study was conducted on patients with chronic renal failure at Murjan Teaching Hospital in Babylon city during the period. The study included a sample of 70 patients (40 males, 30 females) with chronic renal failure, their ages ranged from 30-65, and 60 (30 males, 30 females) healthy without the disease of the same age. The result was a significant decrease in the number of red and white blood cells, hemoglobin concentration, hematocrit and platelets in patients with chronic renal failure, The result has been showed significant level in enzymes activity for transfer of amine group (alanine amino transferase, aspartate amino transferas) and phosphatase alkaline and also concentration of total bilirubin in patient with compare with healthy, Significantly increases, were found in the concentration of urea, uric acid and creatinine, as well as the concentration of calcium and phosphorous ions in the blood serum of patients compared to healthy controls.

• Journal of the Korean Society of Radiology
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• v.16 no.7
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• pp.857-862
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• 2022

The purpose of this study was to evaluate a three-dimensional conformal radiotherapy (3D-CRT) treatment plan with regard to head tilting in whole-brain radiotherapy (WBRT) using TomoDirect (TD) mode in Tomotherapy. WBRT 3D-CRT by TD was compared for a total of five head tilt angles (-20°, -10°, 0°. +10° and +20°). The dose homogeneity index (HI) and prescription dose index (CI) were calculated to confirm the target coverage. The maximum and average doses for critical organs such as the lens, eyeball and parotid glands were calculated for different angles of head tilting. The HI and CI were closet to the result value of 1 at the head tilted angle +10° and +20°. At a head tilted angle of +10°, the dose to the lens and eyeballs decreased by about 74% and about 30%, when compared with the reference angle (0°), respectively. The results of this study suggest that a head angle of +10 with chin-up would save adequate target coverage and reduce exposure dose to the lens.

• Journal of the Korean Society of Radiology
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• v.17 no.5
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• pp.775-782
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• 2023

In order to overcome practical limitations in installing, managing and operating MRI machines with expensive equipment, this study developed and utilized virtual reality (VR) experience education by combining virtual reality (VR) with magnetic resonance imaging devices. The Students who experienced virtual reality-based educational systems were surveyed to identify possible side effects during the experience and self-directed learning ability and academic self-efficacy surveys were conducted to analyze the impact of virtual reality-based practice on learning. In the analysis of the self-directed learning ability survey there was no difference in the average between the student group who experienced education and the student group who did not but there was a significant difference in the average for each group. Virtual Reality-based practical education is expected to provide an efficient practice system by providing new learning methods and opportunities for education that can be repeated anytime, anywhere regardless of time and space.

• Korean Journal of Radiology
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• v.24 no.3
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• pp.247-258
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• 2023

Objective: To localize the neuroanatomical substrate of rapid eye movement sleep behavior disorder (RBD) and to investigate the neuroanatomical locational relationship between RBD and α-synucleinopathy neurodegenerative diseases. Materials and Methods: Using a systematic PubMed search, we identified 19 patients with lesions in different brain regions that caused RBD. First, lesion network mapping was applied to confirm whether the lesion locations causing RBD corresponded to a common brain network. Second, the literature-based RBD lesion network map was validated using neuroimaging findings and locations of brain pathologies at post-mortem in patients with idiopathic RBD (iRBD) who were identified by independent systematic literature search using PubMed. Finally, we assessed the locational relationship between the sites of pathological alterations at the preclinical stage in α-synucleinopathy neurodegenerative diseases and the brain network for RBD. Results: The lesion network mapping showed lesions causing RBD to be localized to a common brain network defined by connectivity to the pons (including the locus coeruleus, dorsal raphe nucleus, central superior nucleus, and ventrolateral periaqueductal gray), regardless of the lesion location. The positive regions in the pons were replicated by the neuroimaging findings in an independent group of patients with iRBD and it coincided with the reported pathological alterations at post-mortem in patients with iRBD. Furthermore, all brain pathological sites at preclinical stages (Braak stages 1-2) in Parkinson's disease (PD) and at brainstem Lewy body disease in dementia with Lewy bodies (DLB) were involved in the brain network identified for RBD. Conclusion: The brain network defined by connectivity to positive pons regions might be the regulatory network loop inducing RBD in humans. In addition, our results suggested that the underlying cause of high phenoconversion rate from iRBD to neurodegenerative α-synucleinopathy might be pathological changes in the preclinical stage of α-synucleinopathy located at the regulatory network loop of RBD.