• Title/Summary/Keyword: High Accuracy

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Is $^{99m}Tc$-MDP Mammoscintigraphy Useful in Patients with Breast Mass Lesions? ($^{99m}Tc$-MDP 유방 스캔은 유방 종괴의 감별진단에 임상적인 유용성이 있는가?)

  • Park, Seok-Gun;Lee, Yeon-Hee;Rhyu, Jin-Woo;You, Sun-Mee
    • The Korean Journal of Nuclear Medicine
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    • v.32 no.2
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    • pp.151-160
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    • 1998
  • Purpose: Piccolo et al. advocated the usefulness of $^{99m}Tc$-MDP breast scan in differential diagnosis of breast mass with high accuracy. But there are little or no follow-up studies about it as we know. We studied $^{99m}Tc$-MDP uptake pattern and lesion/background ratio in patients complaining palpable breast lesions to evaluate the clinical usefulness of $^{99m}Tc$-MDP scan. Materials and Methods: Total 34 patients were studied with physical examination, mammo-gram and $^{99m}Tc$-MDP scan prospectively. Anteroposterior and both lateral view of breast were obtained 5 minutes after iv injection of 740 MBq $^{99m}Tc$-MDP. Breast uptake pattern of $^{99m}Tc$-MDP was analyzed by a grade system: 0=no uptake, grade 1=bilateral diffuse uptake, grade 2=asymmetric faint uptake, grade 3=focal hot uptake. 20 cases were pathologically confirmed by excision biopsy or aspiration biopsy. 14 cases were normal in physical examination and mammogram. Results: Pathologic results showed 7 carcinomas, 6 benign solid tumors, and 7 fibrocystic changes. Grade 3 pattern of $^{99m}Tc$-MDP uptake was noted in 4/7 carcinomas, 3/6 benign solid tumors, and 1/7 fibrocystic changes. Grade 2 pattern was 217, 0/7, 3/7 respectively. The average L/B ratio was 1.66 in carcinomas, 1.68 in benign solid masses, 1.20 in fibrocystic diseases, 1.05 in normal patients. L/B ratio was higher in carcinoma and benign mass groups than in fibrocystic change and normal control groups(p=0.005). But there was no statistical difference between L/B ratio of malignant mass group and benign mass group. Conclusion: $^{99m}Tc$-MDP scan is not suitable to routine clinical use for breast mass diagnosis. It might be used in limited conditions when whole body bone scan is planned.

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The Usefulness Assessment of Attenuation Correction and Location Information in SPECT/CT (SPECT/CT에서 감쇠 보정 및 위치 정보의 유용성 평가)

  • Choi, Jong-Sook;Jung, Woo-Young;Shin, Sang-Ki;Cho, Shee-Man
    • The Korean Journal of Nuclear Medicine Technology
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    • v.12 no.3
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    • pp.214-221
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    • 2008
  • Purpose: We make a qualitative analysis of whether Fusion SPECT/CT can find lesion's anatomical sites better than existing SPECT or not, and we want to show the usefulness of SPECT/CT through finding out effects of CT attenuation correction on SPECT images. Materials and Method: 1. The evaluation of fusion images: This study comprised patients who was tested $^{131}I$-MIBG, Bone, $^{111}In$-Octreotide, Meckel's diverticulum, Parathyroid MIBI with Precedence 16 or Symbia T2 from 2008 Jan to Aug. We compared SPECT/CT image with non fusion image and make a qualitative analysis. 2. The evaluation of attenuation correction: We classified 38 patients who was tested 201Tl myocardial exam with Symbia T2 into 5 sections by using Cedars Sinai' QPS program - Ant, Inf, Lat, Septum, Apex. And we showed each section's perfusion states by percentage. We compared the each section's perfusion-states differences between CT AC and Non AC by average${\pm}$standard deviation. Results: 1. The evaluation of fusion images : In high energy $^{131}I$ cases, it was hard to grasp exact anatomical lesions due to difference between regions and surrounding lesions' uptake level. After combining with CT, we could grabs anatomical lesion more exactly. And in meckel's diverticulum case or to find lesions around bowels or organs with $^{111}In$ cases, it demonstrates its superiority. Bone SPECT/CT images help to distinguish between disk spaces certainly and give correct results. 2. The evaluation of attenuation correction: There is no significant difference statistically in Ant and Lat (p>0.05), but there is a meaningful difference in Inferior, Apex and Septum (p<0.05). AC perfusion at inferior wall in the 5 sections of myocardium: The perfusion difference between Non AC perfusion image ($68.58{\pm}7.55$) and CT corrected perfusion image ($76.84{\pm}6.52$) was the largest by $8.26{\pm}4.95$ (p<0.01, t=10.29). Conclusion: Nuclear medicine physicians can identify not only molecular image which shows functional activity of lesions but also anatomical location information of lesions with more accuracy using the combination of SPECT and CT systems. Of course this combination helps nuclear medicine physician find out the abnormal parts. Moreover combined data sets help separate between normal group and abnormal group in complicated body part. So clinicians can carry out diagnosis and treatment planning at the same time with a single test image. In addition, when we examine a myocardium in thorax where attenuation can occur easily, we can trust perfusion more in a certain region in SPECT test because CT provides the capability for accurate attenuation correction. In these reasons, we think we can prove the justice after treatment fusion image.

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Environmentally Associated Spatial Distribution of a Macrozoobenthic Community in the Continental Shelf off the Southern Area of the East Sea, Korea (한국 동해 남부해역 대륙붕에 서식하는 대형저서동물군집 공간분포를 결정하는 환경요인)

  • Lee, Jung-Ho;Lee, Jung-Suk;Park, Young-Gyu;Kang, Seong-Gil;Choi, Tae Seob;Gim, Byeong-Mo;Ryu, Jongseong
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.19 no.1
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    • pp.66-75
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    • 2014
  • This study aims to understand environmental factors that determine spatial distribution of macrozoobenthic community in the southern area (ca 100-500 m depth) of East Sea, Korea, known as a candidate site for carbon storage under the seabed. From sixteen locations sampled in the summer of 2012, a total of 158 species were identified, showing density of $843indiv/m^2$ and biomass of $26.2g\;WW/m^2$, with increasing faunal density towards biologically higher diverse locations. Principal component analysis showed that a total of 33 environmental parameters were reduced to three principal components (PC), indicating sediment, bottom water, and depth, respectively. As sand content was increasing, number of species increased but biomass decreased. Six dominant species including two bivalve species favored high concentrations of ${\Omega}$ aragonite and ${\Omega}$ calcite, indicating that the corresponding species can be severely damaged by ocean acidification or $CO_2$ effluent. Cluaster analysis based on more than 1% density dominant species classified the entire study area into four faunal assemblage (location groups), which were delineated by characteristic species, including (A) Ampelisca miharaensis, (B) Edwardsioides japonica, (C) Maldane cristata, (D) Spiophanes kroeyeri, and clearly separated in terms of geography, bottom water and sediment environment. Overall, a discriminant function model was developed to predict four faunal assemblages from five simply-measured environmental variables (depth, sand content in sediment, temperature, salinity and pH in bottom water) with 100% accuracy, implying that benthic faunal assemablages are closed linked to certain combinations of abiotic factors.

A Performance Comparison of the Mobile Agent Model with the Client-Server Model under Security Conditions (보안 서비스를 고려한 이동 에이전트 모델과 클라이언트-서버 모델의 성능 비교)

  • Han, Seung-Wan;Jeong, Ki-Moon;Park, Seung-Bae;Lim, Hyeong-Seok
    • Journal of KIISE:Information Networking
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    • v.29 no.3
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    • pp.286-298
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    • 2002
  • The Remote Procedure Call(RPC) has been traditionally used for Inter Process Communication(IPC) among precesses in distributed computing environment. As distributed applications have been complicated more and more, the Mobile Agent paradigm for IPC is emerged. Because there are some paradigms for IPC, researches to evaluate and compare the performance of each paradigm are issued recently. But the performance models used in the previous research did not reflect real distributed computing environment correctly, because they did not consider the evacuation elements for providing security services. Since real distributed environment is open, it is very vulnerable to a variety of attacks. In order to execute applications securely in distributed computing environment, security services which protect applications and information against the attacks must be considered. In this paper, we evaluate and compare the performance of the Remote Procedure Call with that of the Mobile Agent in IPC paradigms. We examine security services to execute applications securely, and propose new performance models considering those services. We design performance models, which describe information retrieval system through N database services, using Petri Net. We compare the performance of two paradigms by assigning numerical values to parameters and measuring the execution time of two paradigms. In this paper, the comparison of two performance models with security services for secure communication shows the results that the execution time of the Remote Procedure Call performance model is sharply increased because of many communications with the high cryptography mechanism between hosts, and that the execution time of the Mobile Agent model is gradually increased because the Mobile Agent paradigm can reduce the quantity of the communications between hosts.

Rapid Detection of Radioactive Strontium in Water Samples Using Laser-Induced Breakdown Spectroscopy (LIBS) (Laser-Induced Breakdown Spectroscopy (LIBS)를 이용한 방사성 스트론튬 오염물질에 대한 신속한 모니터링 기술)

  • Park, Jin-young;Kim, Hyun-a;Park, Kihong;Kim, Kyoung-woong
    • Economic and Environmental Geology
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    • v.50 no.5
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    • pp.341-352
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    • 2017
  • Along with Cs-137 (half-life: 30.17 years), Sr-90 (half-life: 28.8 years) is one of the most important environmental monitoring radioactive elements. Rapid and easy monitoring method for Sr-90 using Laser-Induced Breakdown Spectroscopy (LIBS) has been studied. Strontium belongs to a bivalent alkaline earth metal such as calcium and has similar electron arrangement and size. Due to these similar chemical properties, it can easily enter into the human body through the food chain via water, soil, and crops when leaked into the environment. In addition, it is immersed into the bone at the case of human influx and causes the toxicity for a long time (biological half-life: about 50 years). It is a very reductive and related with the specific reaction that makes wet analysis difficult. In particular, radioactive strontium should be monitored by nuclear power plants but it is very difficult to be analysed from high-cost problems as well as low accuracy of analysis due to complicated analysis procedures, expensive analysis equipment, and a pretreatment process of using massive chemicals. Therefore, we introduce the Laser-Induced Breakdown Spectroscopy (LIBS) analysis method that analyzes the elements in the sample using the inherent spectrum by generating plasma on the sample using pulse energy, and it can be analyzed in a few seconds without preprocessing. A variety of analytical plates for samples were developed to improve the analytical sensitivity by optimizing the laser, wavelength, and time resolution. This can be effectively applied to real-time monitoring of radioactive wastewater discharged from a nuclear power plant, and furthermore, it can be applied as an emergency monitoring means such as possible future accidents at a nuclear power plants.

Determination of Carazolol and Azaperone in Livestock and Fishery Products Using Liquid Chromatography-tandem Mass Spectrometry (축수산물에서 LC-MS/MS를 이용한 카라졸롤 및 아자페론 분석)

  • Choi, Soo Yeon;Kang, Hui-Seung;Kim, Joohye;Cheon, So-Young;Jeong, Jiyoon;Cho, Byung-Hoon;Lee, Kang-Bong
    • Journal of Food Hygiene and Safety
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    • v.33 no.3
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    • pp.176-184
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    • 2018
  • The aim of the present work was to develop simultaneous methods of quantification of carazolol, azaperone, and azaperol residues in livestock and fishery products using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Samples were extracted from beef, pork, chicken, egg, milk and shrimp using acetonitrile (ACN); while flat fish and eel were extracted using 80% ACN. For purification, ACN saturated n-hexane was used to remove fat composition. The standard calibration curves showed good linearity as correlation coefficients; $r^2$ was > 0.99. Average recoveries expressed were within the range of 67.9-105% for samples fortified at three different levels ($0.5{\times}MRL$, $1{\times}MRL$ and $2{\times}MRL$). The correlation coefficient expressed as precision was within the range of 0.55-7.93%. The limit of quantification (LOQ) was 0.0002-0.002 mg/kg. The proposed analytical method showed high accuracy and acceptable sensitivity based on Codex guideline requirements (CAC/GL71-2009). This method can be used to analyze the residue of carazolol, azaperone, and azaperol in livestock and fishery products.

Review of the Radiation Risk and Clinical Efficacy Associated with Computed Tomography Cancer Screening (암의 조기발견을 위한 CT촬영에서의 임상적 효능과 방사선위해에 대한 고찰)

  • Kim, Hyun Ja
    • Journal of Radiation Protection and Research
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    • v.38 no.4
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    • pp.214-227
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    • 2013
  • Computed tomographic scan as a screening procedures in asymptomatic individuals has seen a steady increase with the introduction of multiple-raw detector CT scanners. This report provides a brief review of the current controversy surrounding CT cancer screening, with a focus on the radiation induced cancer risks and clinical efficacy. 1. A large study of patients at high risk of lung cancer(the National Lung Screening Trial[NLST]) showed that CT screening reduced cancer deaths by 20%(1.33% in those screened compared with 1.67% in those not screened). The rate of positive screening tests was 24.2% and 96.4% of the positive screening results in the low-dose CT group were false-positive. Radiation induced lung cancer risk was estimated the most important in screening population because ERR of radiation induced lung cancer does not show the decrease with increasing age and synergistic connection between smoking and radiation risk. Therefore, the radiation risk may be on the same order of magnitude as the benefit observed in the NLST. Optimal screening strategy remain uncertain, CT lung cancer screening is not yet ready for implementation. 2. Computed tomographic colonography is as good as colonoscopy for detecting colon cancer and is almost as good as colonoscopy for detecting advanced adenomas, but significantly less sensitive and specific for smaller lesions and disadvantageous for subsequent therapeutic optical colonoscopy if polyps are detected. The average effective dose from CT colonography was estimated 8-10 $mS{\nu}$, which could be a significant dose if administered routinely within the population over many years. CT colonography should a) achieve at least 90% sensitivity and specificity in the size category from 6 and 10 mm, b) offer non-cathartic bowl preparation and c) be optimized and standardized CT parameters if it is to be used for mass screening. 3. There is little evidence that demonstrates, for whole-body scanning, the benefit outweighs the detriment. This test found large portion of patient(86~90.8%) had at least one abnormal finding, whereas only 2% were estimated to have clinically significant disease. Annual scans from ages 45 to 75 years would accrue an estimated lifetime cancer mortality risk of 1.9%. There is no group within the medical community that recommends whole-body CT. No good studies indicate the accuracy of screening CT, at this time. The benefit/risk balance for any of the commonly suggested CT screening techniques has yet to be established. These areas need further research. Therefore wild screening should be avoided.

Distribution Patterns and Ecological Characters of Paulownia coreana and P. tomentosa in Busan Metropolitan City Using MaxEnt Model (MaxEnt 모형을 활용한 부산광역시 내 오동나무 및 참오동나무의 분포 경향과 생태적 특성)

  • Lee, Chang-Woo;Lee, Cheol-Ho;Choi, Byoung-Ki
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.35 no.2
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    • pp.87-97
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    • 2017
  • Paulownia species has long been recognized in Korean traditional culture and the values of the species have been researched in various focuses. However, studies on distribution and ecological characteristics of the species are still needed. This study aimed to identify distribution trends and ecological characteristics of two Paulownia species in Busan metropolitan city using the MaxEnt model. The MaxEnt model was established based on the environmental factors such as positioning information of the Paulownia species, topography, climate and degree of anthropogenic disturbance potentiality (ADP), which was collected in the on-site research. The study verified that the accuracy of the model was appropriate as the AUC value of Paulownia coreana and P. tomentosa was 0.809, respectively. In terms of the distribution trends of the two Paulownia species in the research area depending on the distribution model, they were both mainly distributed in downtown where built-up area and bare ground were densely concentrated. The potential distribution area of the two species was identified as $137.4km^2$ for P. coreana and $135.0km^2$ for P. tomentosa. The distribution probability was high in Jung-gu, Dongrae-gu, Busanjin-gu and Yeonje-gu. As a result of the analysis on contribution of the environmental factors, it was turned out that the degree of anthropogenic disturbance potentiality (ADP) contributed to distribution of P. coreana and P. tomentosa by about 50%, and the contribution of the environmental factors had a positive correlation with the degree of ADP. The elevation had a negative correlation with both the two species, which was considered because the species must compete more with native species in natural habitats as the altitude above sea level rises. The research findings demonstrated numerically that the distribution of P.coreana and P. tomentosa depended on artificial activities, and indicated the relevance with the Korean traditional landscape. These findings are expected to provide meaningful information in using, preserving and restoring Paulownia species.

The Significance of Sentinel Node Biopsy in Malignant Melanoma and Squamous Cell Carcinoma of Lower Extremities (하지에 발생한 악성흑색종 및 편평상피세포암에서 소속 림프절 생검의 의미)

  • Kim, Jae-Do;Lee, Gun-Woo;Kwon, Young-Ho;Chung, So-Hak
    • The Journal of the Korean bone and joint tumor society
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    • v.16 no.2
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    • pp.69-73
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    • 2010
  • Purpose: Sentinel lymph node (SLNB) is the first confronted lymph node from primary lesion of tumor through lymphatic drainage, which is important for determining early metastasis and setting guidelines for treatment. We reported significant of sentinel lymph node biopsy in malignant melanoma (MM) and squamous cell carcinoma (SCC) of lower extremities. Materials and Methods: Twenty-five cases of surgically treatment and being possible for follow up more than 1 year among the patients who were diagnosed as MM and SCC in this institution from Sep. 2005 to Jan. 2009, and 10 cases of them were performed SLNB. Average age was 64 years old, and 15 cases of male and 10 cases of female were in this group. Results: 3 years overall survival rate was 100% and 3 years disease-free survival rate was 76%. Metastasis occurred in total 6 patients, 4 cases of inguinal lymph nodes, 1 case of soft tissue around knee, 1 case of left achilles tendon. In 15 cases of not performing SLNB, overall survival rate was 93.3% and disease-free survival rate was 73.3%. In 10 cases of performing SLNB, overall survival rate was 100% and disease-free survival rate was 90%. And only 1 case showed positive finding in the biopsy, and none of the 10 cases showed metastasis in follow-up. Conclusion: SLNB leads simpler and less complications compared to prior elective lymph node dissection, and shows high degree of accuracy. Throughout the SLNB, setting guidelines for treatment by accurate staging is thought to be helpful for increasing the survival rate in the patient with MM and SCC.

Method Validation for Determination of Lignan Content in Fermented Sesame by Bioconversion (생물전환된 참깨 발효물의 Lignan 화합물의 분석법 검증)

  • Jung, Tae-Dong;Kim, Jae-Min;Choi, Sun-Il;Choi, Seung-Hyun;Cho, Bong-Yeon;Lee, Jin-Ha;Lee, Sang Jong;Park, Seon Ju;Heo, In Young;Lee, Ok-Hwan
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.5
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    • pp.646-652
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    • 2017
  • The aim of this study was to investigate method validation for determination of sesamol, sesamin, and sesamolin in non-fermented sesame and fermented sesame by bioconversion. For validation, the specificity, linearity, precision, accuracy, limits of detection (LOD), and quantification (LOQ) of sesamol, sesamin, and sesamolin were measured by HPLC. Linearity tests showed that the coefficients of calibration correlation ($R^2$) for sesamol, sesamin, and sesamolin were 0.9999. Recovery rates of lignan contents in non-fermented and fermented sesame were high in the ranges of 100.27~115.10% and 98.43~114.90%, respectively. The inter-day and intra-day precisions of sesamin and sesamolin analyses for non-fermented and fermented sesame were 0.27~1.94% and 0.25~0.69%, respectively. The LOD and LOQ were $0.23{\sim}0.34{\mu}g/g$ and $0.70{\sim}1.03{\mu}g/g$, respectively. These results indicate that the validated method is appropriate for the determination of sesamol, sesamin, and sesamolin.