• Natural Product Sciences
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• 제21권1호
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• pp.34-41
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• 2015

The objective of this study is to characterize a toxicity of Epimedii Herba (EH) in F344 rats and to find a dose levels for the 13 weeks toxicity study. EH is well known as medicinal herb in many Asian countries for traditional medicines of antibacterial and antiviral effects, estrogenic and antiestrogenic effects, and for treatment of osteoporosis, hypotensives, fatigue, kidney disorders, and related complications. However, the indispensable and basic information of toxicological evaluation of EH extract is insufficient to support its safe use. Therefore, we conducted toxicological evaluation of this drug in compliance with OECD and MFDS guideline in this study. The extract of EH was administered orally to F344 rats at dose levels of 0, 500, 1000, 2000, 3500, and 5000 mg/kg/day for 2 weeks. Each group was composed of 5 male and female rats. In this study, there were no treatment of EH-related adverse changes in clinical observations, mortality, body weights, food consumption, urinalysis, gross finding at necropsy, and organ weight examination. Total red blood cell count, hematocrit, mean corpuscular hemoglobin concentration, total cholesterol, and phospholipid were decreased in males and females at 5000 mg/kg/day compared to the control animals. Mean corpuscular volume and reticulocyte counts were increased in males and females at 5000 mg/kg/day compared to control animals. Therefore, we recommend that dose level of 5000 mg/kg/day is a highest treatment group in 13-week EH extract exposure study for further toxicity assessment.

• 방사성폐기물학회지
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• 제21권2호
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• pp.183-191
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• 2023

The potential impact of hypothetical accidents that occur during the immediate and deferred dismantling of the Kori Unit 1 steam generator has been comprehensively evaluated. The evaluation includes determining the inventory of radionuclides in the Steam Generator based on surface contamination measurements, assuming a rate of release for each accident scenario, and applying external and internal exposure dose coefficients to assess the effects of radionuclides on human health. The evaluation also includes calculating the atmospheric dispersion factor using the PAVAN code and analyzing three years of meteorological data from Kori NPP to determine the degree of diffusion of radionuclides in the atmosphere. Overall, the effective dose for residents living in the Exclusion Area Boundary (EAB) of Kori NPP is predicted, an it is found that the maximum level of the dose is 0.034% compared to the annual dose limit of 1 mSv for the general public. This implies that the potential impact of hypothetical accidents on human health discussed above is within acceptable limits.

• 방사성폐기물학회지
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• 제19권1호
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• pp.133-140
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• 2021

This study evaluates the radioactivity of concrete waste that occurs due to large amounts of decommissioned nuclear wastes and then determines the surface dose rate when the waste is packaged in a disposal container. The radiation assessment was conducted under the presumption that impurities included in the bio-shielded concrete contain the highest amount of radioactivity among all the concrete wastes. Neutron flux was applied using the simplified model approach in a sample containing the most Co and Eu impurities, and a maximum of 9.8×104 Bq·g-1 60Co and 2.63×105 Bq·g-1 152Eu was determined. Subsequently, the surface dose rate of the container was measured assuming that the bio-shield concrete waste would be packaged in a newly developed disposal container. Results showed that most of the concrete wastes with a depth of 20 cm or higher from the concrete surface was found to have less than 1.8 mSv·hr-1 in the surface dose of the new-type disposal container. Hence, when bio-shielded concrete wastes, having the highest radioactivity, is disposed in the new disposal container, it satisfies the limit of the surface dose rate (i.e., 2 mSv·hr-1) as per global standards.

• 한국의학물리학회지:의학물리
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• 제35권1호
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• pp.10-15
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• 2024

Purpose: This study aimed to comprehensively investigate the diverse characteristics of a novel commercial bolus, CLEANBOLUS-WHITE (CBW), to ascertain its suitability for clinical application. Methods: The evaluation of CBW encompassed both physical and biological assessments. Physical parameters such as mass density and shore hardness were measured alongside analyses of element composition. Biological evaluations included assessments for skin irritation and cytotoxicity. Dosimetric properties were examined by calculating surface dose and beam quality using a treatment planning system (TPS). Additionally, doses were measured at maximum and reference depths, and the results were compared with those obtained using a solid water phantom. The effect of air gap on dose measurement was also investigated by comparing measured doses on the RANDO phantom, under the bolus, with doses calculated from the TPS. Results: Biological evaluation confirmed that CBW is non-cytotoxic, nonirritant, and non-sensitizing. The bolus exhibited a mass density of 1.02 g/cm³ and 14 shore 00. Dosimetric evaluations revealed that using the 0.5 cm CBW resulted in less than a 1% difference compared to using the solid water phantom. Furthermore, beam quality calculations in the TPS indicated increased surface dose with the bolus. The air gap effect on dose measurement was deemed negligible, with a difference of approximately 1% between calculated and measured doses, aligning with measurement uncertainty. Conclusions: CBW demonstrates outstanding properties for clinical utilization. The dosimetric evaluation underscores a strong agreement between calculated and measured doses, validating its reliability in both planning and clinical settings.

• 대한방사선기술학회지:방사선기술과학
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• 제44권3호
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• pp.195-203
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• 2021

Although intra oral dental x-ray is a lower dose than other radiological examinations, pediatric patients are known to have a higher risk of radiation damage than adults. For this reason, pediatric dental x-ray requires management of dose evaluation and imaging conditions during the examination. In this study, the dose calculation program ALARA-Dental(child/adult) was used to evaluate the organ dose and effective dose exposed to each examination site during intra oral imaging of children during dental radiographic examination, and dose analysis according to the imaging conditions was performed. As a result, the highest organ dose distribution was shown at 0.044 ~ 0.097 mGy in all are as of the mucous membrane of oral cavity except for the maxillary incisors and canines. Also, in the case of the thyroid gland, the maxillary canine and maxillary premolar examination showed 0.027 and 0.020 mGy, respectively, and the dose distribution was 15.4% to 70.0% higher than that of the mandibular examination. As for the effective dose calculated during intra oral imaging, the maxillary anterior and canine examinations showed the highest effective doses of 0.005 and 0.004 mSv, respectively, and the maxillary area examination showed a higher dose distribution on average than the mandible.

• 한국융합학회논문지
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• 제11권10호
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• pp.147-154
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• 2020

본 연구에서는 복합 부가필터(Composite added filtration) 4가지 종류(알루미늄, 니켈, 구리, 아연)를 두께별로 조합하여 X-선 감약에 따른 선량감소와 최적의 영상을 평가하였다. 선량과 화질을 평가는 RQR9 표준 선질을 설정한 X선 발생장치, 면적선량계 그리고 ICY 프로그램이 사용되었다. 화질평가 항목(PSNR, RMSE, SSIM)에서는 PSNR값이 30 dB 이상이 되는 영상들만을 분석하였다. 그 결과 선량평가에서 가장 우수한 조합은 3 mmAl + 0.6 mmNi(0.16µGy㎡)이었고, 화질평가에서 가장 우수한 필터는 0.9 mmAl (PSNR 34.24dB, RMSE 79.52, SSIM 0.24)이었다. 본 연구에서는 선량적 측면과 화질적 측면이 언급되었기에 향후 환자의 피폭선량과 최적의 영상에 대한 더 많은 연구가 필요할 것으로 사료된다.

• 대한방사선기술학회지:방사선기술과학
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• 제44권2호
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• pp.109-115
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• 2021

In this study, a physical evaluation of internal radiation exposure in children was conducted using nuclear medicine test(Renal DTPA Dynamic Study) to simulate the distribution and effects of the radiation throughout the tracer kinetics over time. Monte Carlo simulations were performed to determine the internal medical radiation exposure during the tests and to provide basic data for medical radiation exposure management. Specifically, dose variability based on changes in the tracer kinetic was simulated over time. The internal exposure to the target organ (kidney) and other surrounding organs was then quantitatively evaluated and presented. When kidney function was normal, the dose to the target organ(kidney) was approximately 0.433 mGy/mCi, and the dose to the surrounding organs was approximately 0.138-0.266 mGy/mCi. When kidney function was abnormal, the dose to the surrounding organs was 0.228-0.419 mGy/mCi. This study achieved detailed radiation dose measurements in highly sensitive pediatric patients and enabled the prediction of radiation doses according to kidney function values. The proposed method can provide useful insights for medical radiation exposure management, which is particularly important and necessary for pediatric patients.

• 대한방사선기술학회지:방사선기술과학
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• 제43권5호
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• pp.343-351
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• 2020

This study analyzed dose reduction and quality of images through dose reduction tools and shielding board to protect sensitive eye lens in radiation during orbit CT examinations for clinical data use. During CT scans of the phantom, surface dose (CT scanner dosimetry phantom, ion chamber-3 times) and quality of image (radiosurgery head phantom, visual assessment-2 times, HU standard deviation) were evaluated using X-care which is dose reduction tools and bismuth shielding board. The results of experiments of eight conditions showed a relatively reduced dose in all other conditions compared to when no conditions were set. In particular, the area corresponding to the ophthalmic part reduced the surface dose by up to 45.7 %. The visual evaluation of images by specialists and the quality evaluation of images analyzed by HU standard deviation were clinically closest to the use of X-care and shielding board (1 cm in height). Therefore, it is believed that the use of shielding board in a suitable location with dose reduction tools while investigating the optimal radiation dose will reduce the exposure dose of sensitive lens at radiation while maintaining the quality of the images with high diagnostic value.

• Asian Pacific Journal of Cancer Prevention
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• 제15권23호
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• pp.10413-10420
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• 2015

Side effects are an unavoidable consequence of chemotherapy drugs, during which liver injury often takes place. The current study was designed to investigate the protective effect of Astragalus polysaccharides (APS) against the hepatotoxicity induced by frequently-used chemical therapy agents, cyclophosphamide (CTX), docetaxel (DTX) and epirubicin (EPI)) in mice. Mice were divided into five groups, controls, low or high dose groups ($DTX_L$, $CTX_L$, $EPI_L$ or $DTX_H$, $CTX_H$, $EPI_H$), and low or high dose chemotherapeutics+APS groups ($DTX_L$+APS, $CTX_L$+APS, $EPI_L$+APS or $DTX_H$+APS, $CTX_H$+APS, $EPI_H$+APS). Controls were treated with equivalent normal saline for 28 days every other day; low or high dose group were intraperitoneal (i.p) injected with low or high doses of CTX, DTX and EPI for 28 days every other day; low or high dose chemotherapeutics+APS group were separately intraperitoneal (i.p) injected with chemotherapeutics for 28 days every other day and i.p with APS (100 mg/kg) for 7 days continually from the 22th to the 28th days. The body weight, serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), histopathological features, and ultrastructure morphological change of liver tissues, protein expression level of caspase-3 were estimated at different time points. With high dose treatment of DTX, CTX and EPI, weight gain was inhibited and serum levels of ALT and AST were significantly increased. Sections of liver tissue showed massive hepatotoxicity in $CTX_H$ group compared to the control group, including hepatic lobule disorder, granular and vacuolar degeneration and necrosis in hepatic cells. These changes were confirmed at ultrastructural level, including obvious pyknosis, heterochromatin aggregation, nuclear membrane resolution, and chondrosome crystal decrease. Western blotting revealed that the protein levels of caspase-3 increased in $CTX_H$ group. The low dose groups exhibited trivial hepatotoxicity. More interestingly, after 100 mg/kg APS, liver injury was redecued not only regarding serum transaminase activities (low or high dose chemotherapeutics+APS group), but also from pathological and ultrastructural changes and the protein levels of caspase-3 ($CTX_H$+APS group). In conclusion, DTX, CTX and EPI induce liver damage in a dose dependent manner, whereas APS exerted protective effects.

• 한국방사선학회논문지
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• 제17권6호
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• pp.801-808
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• 2023

소아 두부 CT 검사 시 방사선 피폭 최소화와 진단적 가치가 높은 영상을 확보하기 위하여 Volume Axial Mode, High Pitch Mode, Helical Mode 간 피폭 선량과 영상의 비교 분석을 통하여 Volume Axial Mode의 유용성을 평가하였다. 1세 미만의 소아 두부 CT Helical Mode, High Pitch Mode, Volume Axial Mode에서 70, 80, 100 kVp의 관전압에 따라 영상평가와 선량평가를 시행하였다. 영상평가는 각 영상에 ROI를 설정해 SNR과 CNR을 산출하여 영상평가를 진행하였으며 일원배치 분산분석(ONE-WAY ANOVA)을 사용하여 통계적 유의성을 평가하였고, 선량평가는 검사 후 장비에서 직접 제공하는 Dose Report에 표시되는 DLP값을 이용하여 비교 분석하였다. Volume Axial Mode를 사용하여 검사하였을 때, DLP 값은 전체적으로 낮게 나왔고, SNR과 CNR은 각각 ROI와 kVp별 차이를 가졌다. Volume Axial Mode가 다른 Scan Mode와 비교하여 영상의 질을 평가하였을 때, 그 차이 값이 균일하지 않아 특정 Mode가 우수하다고 볼 수 없었으나 선량 측면에서는 가장 피폭선량을 줄일 수 있었다. 또한 Volume Axial Mode의 짧은 스캔 시간과 Table의 이동 없이 제자리에서 검사 할 수 있는 점은 방사선 감수성이 높은 1세 미만 소아 CT검사에서 유용하게 적용된다.