• Title/Summary/Keyword: dose quality factor

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New thyroid models for ICRP pediatric mesh-type reference computational phantoms

  • Yeon Soo Yeom ;Chansoo Choi ;Bangho Shin ;Suhyeon Kim ;Haegin Han ;Sungho Moon ;Gahee Son;Hyeonil Kim;Thang Tat Nguyen;Beom Sun Chung;Se Hyung Lee ;Chan Hyeong Kim
    • Nuclear Engineering and Technology
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    • v.54 no.12
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    • pp.4698-4707
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    • 2022
  • As part of the ICRP Task Group 103 project, we developed ten thyroid models for the pediatric mesh-type reference computational phantoms (MRCPs). The thyroid is not only a radiosensitive target organ needed for effective dose calculation but an important source region particularly for radioactive iodines. The thyroid models for the pediatric MRCPs were constructed by converting those of the pediatric voxel-type reference computational phantoms (VRCPs) in ICRP Publication 143 to a high-quality mesh format, faithfully maintaining their original topology. At the same time, we improved several anatomical parameters of the thyroid models for the pediatric MRCPs, including the mass, overlying tissue thickness, location, and isthmus dimensions. Absorbed doses to the thyroid for the pediatric MRCPs for photon external exposures were calculated and compared with those of the pediatric VRCPs, finding that the differences between the MRCPs and VRCPs were not significant except for very low energies (<0.03 MeV). Specific absorbed fractions (target ⟵ thyroid) for photon internal exposures were also compared, where significant differences were frequently observed especially for the target organs/tissues close to the thyroid (e.g., a factor of ~1.2-~327 for the thymus as a target) due mainly to anatomical improvement of the MRCP thyroid models.

A study of beam hardening effect reduction occur in brain CT (Brain CT에서 발생하는 선속경화현상 감소방안에 관한 연구)

  • Kim, Hyeon-ju
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.12
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    • pp.8479-8486
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    • 2015
  • This study aim is occur in brain CT cause of beam hardening effect and reducing method, We will scan Bone opaque bead phantom on variation of image on the influence factor with equipment called 'Samatom Senation 16' with following listed herein : tube voltage, tube current, slice thickness, gantry angle, base line which affect beam-hardening effect. After that we are going to start Quantitative Analysis resulted in previous scanning and Qualitative Assessment with CT image sheet evaluation. result of quantitative analysis 140kVp $31.56{\pm}2.89HU$ on tube voltage, 150mA $-3.87{\pm}0.12HU$ on tube current, 3mm on slice thickness, and $13.31{\pm}1.03HU$ IOML on gantry angle which was the least beam-hardening effect. Like Qualitative Analysis, we went through Qualitative Assessment and most of valuers got a result of 140kVp on tube voltage, 150mA on tube current, 3mm on slice thickness. As before valuers evaluated gantry angle that scanned image from IOML or OML was the least beam-hardening effect occured. There are meaningful differences when we compare all theses factors statistically(P<0.05). therefore We consider that Minimizing artifact that caused by beam-hardening effect can provide better quality of image to deciphers and patients. if we rise tube voltage in permissible dose limit, set tube current in a limit that does not effect to image quality, use slice thickness too thin enough to harm resolution, use IOML or OML on gantry angle.

Contamination Assessment of Heavy Metals in River Sediments (For the Surface Sediments from Nakdong River) (하천 퇴적물 내 중금속 오염도 평가에 관한 연구 (낙동강 수계 표층 퇴적물을 대상으로))

  • Kim, Shin;Ahn, Jungmin;Jung, Kangyoung;Lee, Kwonchul;Kwon, Heongak;Shin, Dongseok;Yang, Deukseok
    • Journal of Korean Society on Water Environment
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    • v.33 no.4
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    • pp.460-473
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    • 2017
  • In order to certificate the contamination assessment of heavy metals in surface sediments from the Nakdong river. Surface sediments were collected of 24 sampling sites (main 14st., tributary 10st.) and analyzed for grain size heavy metals contents. Study area mainly composed of sand (avg. 94.1%) and mean grain size was $1.46{\Phi}$ on average. Heavy metals contents (avg. Al: 12.5%, Zn; 74.4, Cr: 45.3, Li: 26.0, Pb: 17.1, Ni: 10.5, Cu: 7.8, Cd: 0.22 mg/kg) were relatively high contents in the composed of fine sediments. In addition, the results of pearson's correlation coefficient showed that most heavy metals and grain size (silt and clay) were highly correlated. The contents of Zn (6st.) and Ni (1st.) evaluated as moderately polluted, Zn (6st.) evaluated as LEL when compared with sediment quality standard of USEPA and Ontario sediment quality guidelines. Most heavy metals contents were I levels that dose not affected the benthos when compared with sediment pollution evaluation standard of NIER. The results of EX, EF, Igeo and CF showed the contents of Zn, Pb and Cd exceed the background contents and distributing of anthropogenic pollution and evaluated as moderately polluted level. And Nm-08 were relatively high level of contamination in the study area. However as results of PLI (less than 1), all sampling sites were evaluated unpolluted level.

Quality Characteristics of Cookies with Added Concentrations of Garlic Juice (마늘 즙 첨가에 따른 쿠키의 품질특성)

  • Shin, Jung-Hye;Lee, Soo-Jung;Choi, Duck-Joo;Kwen, O-Chen
    • Korean journal of food and cookery science
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    • v.23 no.5
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    • pp.609-614
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    • 2007
  • This study aimed to evaluate the physicochemical and sensory properties of the cookies that were prepared with different concentrations [0, 0.5, 1, 2, 4, and 6 % (w/w)]. The pH of the cookie dough increased significantly at all garlic juice concentrations greater than 1%. The highest dough density value was 1.23, which occurred in the 2% added group; however there was no remarkable differences among the test groups. The spread factor of the cookies showed an inverse relationship with the garlic juice concentration as compared to the control group (10.63). Hardness decreased with increasing garlic juice concentration at levels greater than 1%, and it ranged from 1857.92 to 1695.02. In addition, the L-value decreased with increasing garlic juice concentration, while the a-value gradually increased. In the case of the b-value, however, no significant difference was found compared to that of the control group. In the sensory evaluation, the color of the cookies (3.44-5.11) increased dose dependently with the garlic juice concentration. Taste scores were higher with garlic juice additions over 2%; whereas flavor was considerably greater compared to that of control group. The overall acceptability of the garlic juice cookies was higher than that of the control group. From this investigation, the optimal concentrations of added garlic juice for improvements in cookie quality were found in the range of 1-2%.

Growth performance, carcass and meat quality of lambs supplemented different vegetable oils

  • Miltko, Renata;Majewska, Malgorzata Paulina;Belzecki, Grzegorz;Kula, Katarzyna;Kowalik, Barbara
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.6
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    • pp.767-775
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    • 2019
  • Objective: The purpose of this study was to evaluate the effect of rapeseed and linseed oil supplementations on performance and meat quality of lambs. Methods: The experiment was conducted on 18 growing (100-day-old) lambs of $19.7{\pm}1.9kg$ live weight, assigned to 3 groups of 6 animals each. Control lambs were fed meadow hay and concentrate alone. Experimental animals additionally received rapeseed or linseed oils at a dose of 50 g/d. The lambs were slaughtered at an average body weight of $35.7{\pm}0.5kg$. Results: The dressing percentage was higher in lambs fed rapeseed oil. Total saturated fatty acids (SFA) and C15:0, C16:0, C17:0, C21:0, C24:0 were lower in longissimus dorsi muscle (MLD) in lambs fed linseed oil. Supplementation of diet with linseed oil decreased concentrations of total monounsaturated fatty acids and C16:1, C17:1, C18:1 cis-9 in MLD. The concentrations of n-3 polyunsaturated fatty acids (PUFA) and C18:3 n-3, C20:5 n-3 in MLD were higher in lambs fed linseed oil than in other groups. Oils supplementation to diets resulted in increased concentration of C22:6 n-3 in MLD. The inclusion of linseed oil into the diet increased the contents of total PUFA, n-3 PUFA and C18:3 n-3, C20:5 n-3, C22:6 n-3 in semitendinosus muscle in comparison to control. A tendency towards a lower n:6/n:3 ratio in MLD was observed when lambs were supplemented linseed oil. Conclusion: The supplementation of linseed oil to diets seems to reduce the concentration of SFA and increase the concentration of n-3 PUFA. The n-6/n-3 ratio is an important nutritional factor, and its value has been favorably decreased below 2, thereby achieving an important target related to human health. Due to these changes carcass fatty acid profile was improved, and so enhanced lamb meat healthy properties.

The Usability Evaluation of the Usefulness of Bismuth Shields in PET/CT Examination (PET/CT 검사에서 비스무스(bismuth) 차폐체의 적용에 따른 유용성 평가)

  • Park, Hoon-Hee;Lee, Juyoung;Kim, Ji-Hyeon;Nam, Kun-Sik;Lyu, Kwang-Yeul;Lee, Tae Soo
    • Journal of radiological science and technology
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    • v.37 no.1
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    • pp.49-56
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    • 2014
  • Recently with CT developed, various studies for reduction of exposure dose is underway. Study of bismuth shields in these studies is actively underway, and has already been applied in the clinical. However, the application of the PET/CT examination was not activated. Therefore, through this study, depending on the application of bismuth shields in the PET/CT examination, we identify the quality of the image and the impact on the Standard Uptake Value (SUV). In this study, to apply to the shielding of the breast, by using the bismuth shields that contains 0.06 mm Pb ingredients, was applied to the PET/CT GEMINI TF 64 (Philips Healthcare, Cleveland, USA). Phantom experiments using the NEMA IEC Body Phantom, images were acquired according to the presence or absence of bismuth shields apply. Also, When applying, images were obtained by varying the spacing 0, 1, 2 cm each image set to the interest range in the depth of the phantom by using EBW-NM ver.1.0. When image of the PET Emission acquires, the SUV was in increased depending on the use of bismuth shields, difference in the depth to the surface from deep in the phantom increasingly SUV increased (P<0.005). Also, when using shields, as the more gab decreased, SUV is more increased (P<0.005). Through this study, PET/CT examination by using of bismuth shields which is used as purpose of reduction dose. When using shields, the difference of SUV resulting from the application of bismuth shields exist and that difference when gab is decrease and surface is wider. Therefore, setting spacing of shield should be considered, if considering the reduction of the variation of SUV and image quality, disease of deep organs should be a priority rather than superficial organ disease. Use of bismuth shielding factor considering the standard clinical examination, decrease unnecessary exposure can be expected to be considered.

Simplistic QA for an Enhanced Dynamic Wedge using the Reversed Wedge Pair Method (역방향 조사방식을 통한 동적쐐기의 품질관리)

  • Lee Jeong Woo;Hong Semie;Suh Tae Suk
    • Progress in Medical Physics
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    • v.15 no.3
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    • pp.161-166
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    • 2004
  • A simplistic quality assurance (QA) method was designed for a Linac built-in enhanced dynamic wedge (EDW), which can be utilized to make wedged beam distributions. For the purpose of implementing the EDW symmetry QA, a film dosimetry system, low speedy dosimetry film, film densitometer and 3D RTP system were used, and the films irradiated by means of a 60$^{\circ}$ Reversed wedge pair (REWP) method. The profiles were then analyzed in terms of their symmetries, including partial treatment, which is the case of stopping it abruptly during EDW irradiation, and the measured and calculated values compared using the Cad Plan Golden Segmented Treatment Table (Golden STT). The result of this experiment was in good agreement, within 1 %, of the 'reversed wedge pair counterbalance effect'. For the QA of the effective wedge factor (EWF), the authors measured EWFs in relation to the 10$^{\circ}$, 15$^{\circ}$, 20$^{\circ}$, 25$^{\circ}$, 30$^{\circ}$, 45$^{\circ}$ and 60$^{\circ}$ EDW, which were compared with the calculated values using the correction factor derived from the Golden STT and the log files produced automatically during the process of EDW irradiation. By means of this method it was capable of check up the safety of effective wedge factor without any other dosimetry system. The EDW QA was able to be completed within 1 hour from irradiation to analysis as a consequence of the simplified QA procedure, with maximized effectiveness. Unlike the metal wedge system, the EDW system was heavily dependent on the dose rates and jaw movements; therefore, its features could potentially cause inaccuracy. The frequent simplistic QA for the EDW is essential, and could secure against the flaw of dynamic treatment that uses the EDW.

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The Usefulness of LEUR Collimator for 1-Day Basal/Acetazolamide Brain Perfusion SPECT (1-Day Protocol을 사용하는 Brain Perfusion SPECT에서 LEUR 콜리메이터의 유용성)

  • Choi, Jin-Wook;Kim, Soo-Mee;Lee, Hyung-Jin;Kim, Jin-Eui;Kim, Hyun-Joo;Lee, Jae-Sung;Lee, Dong-Soo
    • The Korean Journal of Nuclear Medicine Technology
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    • v.15 no.1
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    • pp.94-100
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    • 2011
  • Purpose: Basal/Acetazolamide-challenged brain perfusion SPECT is very useful to assess cerebral perfusion and vascular reserve. However, as there is a trade off between sensitivity and spatial resolution in the selection of collimator, the selection of optimal collimator is crucial. In this study, we examined three collimators to select optimal one for 1-day brain perfusion SPECT. Materials and Methods: Three collimators, low energy high resolution-parallel beam (LEHR-par), ultra resolution-fan beam (LEUR-fan) and super fine-fan beam (LESFR-fan), were tested for 1-day imaging using Triad XLT 9 (TRIONIX). The SPECT images of Hoffman 3D brain phantom filled with 99mTc of 170 MBq and a normal volunteer were acquired with a protocol of 50 kcts/frame and detector rotation of 3 degree. Filterd backprojection (FBP) reconstruction with Butterworth filter (cut off frequencies, 0.3 to 0.5) was performed. The quantitative and qualitative assessments for three collimators were performed. Results: The blind tests showed that LESFR-fan provided the best image quality for Hoffman brain phantom and the volunteer. However, images for all the collimator were evaluated as 'acceptable'. On the other hand, in order to meet the equivalent signal-to-noise ratio (SNR), total acquisition time or radioactivity dose for LESFR-fan must have been increased up to almost twice of that for LEUR-fan and LEHR-par. The volunteer test indicated that total acquisition time could be reduced approximately by 10 to 14 min in clinical practice using LEUR-fan and LEHR-par without significant loss on image quality, in comparison with LESFR-fan. Conclusion: Although LESFR-fan provides the best image quality, it requires significantly more acquisition time than LEUR-fan and LEHR-par to provide reasonable SNR. Since there is no significant clinical difference between three collimators, LEUR-fan and LEHR-par can be recommended as optimal collimators for 1-day brain perfusion imaging with respect to image quality and SNR.

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Study on Relationship between Elderly Group Lifestyle and Selection Attributes in the Health Functional Foods (실버층 라이프스타일에 따른 건강기능식품 선택속성에 관한 연구)

  • Lee, Myung Sook;Kim, Sook Eung
    • Korean Journal of Clinical Pharmacy
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    • v.25 no.4
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    • pp.286-295
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    • 2015
  • Objective: This experiment is to study how elderly group and their various lifestyles interact with health functional foods, according to their selection behavior. Different lifestyles will be observed closely, as well as how different health conditions and consumer involvements will affect critical decision making in selecting health functional foods. Method: Theories and discoveries from original advanced research were compared parallel to the new study. Results: First, cluster analysis and exploratory analysis were performed amongst different elder lifestyles. Lifestyle exploratory analysis was used for healthy, unique, leisure, and economical-style elders. Cluster analysis was used for material trend oriented, health oriented, complacent oriented-style elders. Health Functional Foods' selection trait Exploratory Factor Analysis showed that product's originality (function, uniqueness, specialty, compatibility, distributor, expiration date), quality (amount, daily dose, visual representation, accessibility, portability, natural ingredients), and popularity (product container, brand image, taste and smell, advertised product, domestic or import, well-known function) were the three main causes. Secondly, the amount of benefits for the elderly group health lifestyle were affected by 'Interest in health', 'Notability of the health functional food', and 'Functionality approved mark'. Specifically, the importance of, 'Interest in health', 'Notability of health functional food', and 'Functionality approved mark' were noticeably high within health oriented elders. Lastly, after examining the data from elder lifestyle's relationship with health functional food selection trait, all three different results showed equal importance. If you closely examine material trend oriented elderly group, selection trait showed distinctively high regards in 'Fundamental Attribute', 'Typical Attribute', and 'Cognitive Attribute'. Health oriented elders showed their distinctively high regards in 'Natural Attribute', and less consideration in 'Typical Attribute' and 'Cognitive Attribute'. Complacent oriented-style elderly group showed less focus on 'Fundamental Attribute', and even less in 'Typical Attribute', and 'Cognitive Attribute'. Health oriented elderly group concluded with above data from the fact that they showed most importance and involvement in health beneficial products that are scientifically proven. Material trend oriented elderly group showed balanced traits in their concluded data, showing that they prefer function, safety, as well as the brand image and their reputation. Also, they consider the products' outer elements, such as design and product name, in order to sense inner functions. Conclusion: So, Silver Business corporations must develop products to fulfill the market demands, and strategize marketing plans to better target the correct audience.

Anti-oxidant and Anti-inflammatory Activities of Barley Sprout Extract (보리싹 추출물의 항산화 및 항염증 활성)

  • Eun, Cheong-Su;Hwang, Eun-Young;Lee, Syng-Ook;Yang, Seun-Ah;Yu, Mi-Hee
    • Journal of Life Science
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    • v.26 no.5
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    • pp.537-544
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    • 2016
  • Barley (Hardeum vulgare L.) sprout has received much attention in recent years as a functional food in many countries, especially in Korea and Japan. It has been reported that barley sprouts are comprised of 52.6% polysaccharides, 34.1% proteins, and 4.97% fats, along with a variety of vitamins, minerals, and polyphenols. The purpose of this study was to assess the anti-oxidant and anti-inflammatory activities of the ethanol extracts of barley sprouts. We examined the inhibitory effect of barley sprout extracts (BSE) on inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression, and nitric oxide (NO), prostaglandin E2 (PGE2) and cytokine production in lipopolysaccharide (LPS)-stimulated RAW 264.7 mouse macrophage cells. BSE contains high amounts of phenolics and flavonoids and exhibits potent anti-oxidative activity, as depicted by the DPPH radical-scavenging experiment. The concentration of total phenols was 17.55 μg/ml, and flavonoids, 13.98 μg/ml. We also investigated the anti-inflammatory activities of BSE in LPS-stimulated RAW 264.7 cells. Tumor necrosis factor-alpha and PGE2 production, which had increased as a result of treatment with LPS, were significantly inhibited by BSE in a dose-dependent manner. BSE also significantly suppressed LPS-induced production of NO, and this was accompanied by a decrease in the expression of the iNOS and COX-2 proteins. These results indicate that barley sprouts may be a highly valuable natural product owing to its high-quality functional components as well as its anti-oxidant and anti-inflammatory activities.