• Title/Summary/Keyword: $T_2$ contrast

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Standards for Applying Reasonable Receive Bandwidth to Suppress Metal Artifacts in MRI (MRI 검사 시 금속 인공물 억제를 위한 합리적인 수신대역폭 적용 기준)

  • Se-Jong Yoo;Min-Cheol Jeon;Nam-Yong An;Soon-Yong Kwon;Seong-Ho Kim
    • Journal of the Korean Society of Radiology
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    • v.17 no.7
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    • pp.1115-1122
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    • 2023
  • This study aimed to present reasonable reception bandwidth application standards for the purpose of suppressing metal objects during MRI examinations. For this purpose, T2 contrast images were acquired using high-speed spin echo technology on a phantom made of screws for spinal surgery, and metal objects were detected. In addition, images were obtained by increasing the reception bandwidth from 100 Hz/PX to 800 Hz/PX by 100 Hz/PX. The metal artifacts were determined as the sum of the areas of the signal attenuation area and the signal accumulation area. In addition, Pearson correlation analysis was performed to analyze the pattern of metal artifacts according to imaging variables. As a result, the signal accumulation area did not change significantly as the reception bandwidth increased (p>0.05), but the signal loss area and the area of metal artifacts decreased as the reception bandwidth increased (p<0.05). Interestingly, the area of metal objects decreased to a maximum in the section where the reception bandwidth was increased from 100 Hz/PX to 200 Hz/PX, consistent with the section where the echo spacing was reduced to a maximum due to the increase in reception bandwidth. In addition, the correlation analysis results also showed that the eco spacing was more related to the signal attenuation area and the area of metal objects than to the reception bandwidth. Therefore, if the reception bandwidth is increased for the purpose of reducing metal objects, it is reasonable to set it based on a value that minimizes the echo spacing in consideration of image quality factors.

Making Aids of Magnetic Resonacnce Image Susing 3D Printing Technology (3D 프린트를 활용한 자기공명영상검사 보조기구 제작)

  • Choi, Woo jeon;Ye, Soo young;Kim, Dong hyun
    • Journal of the Korean Society of Radiology
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    • v.10 no.6
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    • pp.403-409
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    • 2016
  • MRI scan is a useful method in the diagnosis of musculoskeletal excellent contrast of the organization. Depending on the patient's musculoskeletal examinations state the type of aids provided the aid is used there is also challenging as well as the costs do not vary. This study was produced by the use of 3D printing technology, an MRI aids. Aids in the production process, then through 3D modeling and then convert stl files using (3D MAX.2014, Fusion360) slicing programs (Cubicreater 2.1ver., Cura 15.4ver) converted to G-code printed on the FDM scheme (Cubicon Style, output was MICRO MAKE). Output is, but in the FDM to evaluate the SNR on the MRI images were compared to the test is the case before use, and then to produce a Water Phantom case of a PLA, ABS, a TPU thickness 3mm, using aids before, It was evaluated in a clinical image after qualitatively. Obtaining an image of SNR Warter Phantom appeared to have been evaluated as T1 NON $123.778{\pm}28.492$, PLA $123.522{\pm}28.373$, ABS $124.461{\pm}25.716$, TPU $124.843{\pm}27.272$. T2 NON $127.421{\pm}26.949$, was rated as PLA $124.501{\pm}27.768$, ABS $128.663{\pm}26.549$, TPU $130.171{\pm}25.998$. The results did not show statistically significant differences. The use of assistive devices before and after images Clinical evaluation method palliative $3.20{\pm}0.88$, $3.95{\pm}0.76$ after using the aids used to aid improved the quality of the image. Production of the auxiliary mechanism using a future 3D printing is expected are thought to be used clinically, it can be an aid making safe and comfortable than the inspection of the patient is an alternative to improve the problems of the aids used in the conventional do.

Biodistribution and Hepatic Metabolism of Galactosylated $^{111}In-Antibody-Chelator$ Conjugates: Comparison with $^{111}In-Antibody-Chelator$ Conjugates ($^{111}In$-표지 갈락토즈 접합 항체의 체내분포 및 간에서의 대사 : $^{111}In$-표지 항체와의 비교연구)

  • Kwak, Dong-Suk;Jeong, Kyu-Sik;Ha, Jeoung-Hee;Ahn, Byeong-Cheol;Lee, Kyu-Bo;Paik, Chang-H.;Lee, Jae-Tae
    • The Korean Journal of Nuclear Medicine
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    • v.37 no.6
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    • pp.402-417
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    • 2003
  • Purpose: To evaluate the use of monoclonal antibody (MoAb) as a carrier of the receptor-binding ligand the receptor mediated uptake into liver and subsequent metabolism of $^{111}In-labeled$ galactosylated MoAb-chelator conjugates were investigated and compared with those of $^{111}In$ labeled MoAb. Materials and Methods : T101 MoAb, $IgG_2$ against human lymphocytic leukemic cell, conjugated with cyclic DTPA dianhydride (DTPA) or 2-p-isothiocyanatobenzyl-6-methyl-DTPA (1B4M) was galactosylated with 2-imino-2-methoxyethyl-1-thio-${\beta}$-D-galactose and then radiolabeled with $^{111}In$. Biodistribution and metabolism study was peformed with two $^{111}In-conjugates$ in mice and rats. Results: $^{111}In-labeled$ T101 and its galactosylated conjugates were taken to the liver by the time, mostly within 10 min. However DTPA conjugate was retained longer in the liver than the 1B4M conjugate (55% vs 20% of injected dose at 44 hr). During this time, the radiornetabolite of DTPA conjugate was excreted similarly into urine (24%) and feces (17%). The radiometabolite of 1B4M was excreted primarily into feces (68%) rather than urine (8%). Size exclusion HPLC analysis of the bile and supernatant of liver homogenate showed two peaks the first (35%) with the retention time (Rt) identical to IgG and the second (65%) with Rt similar to free $^{111}In$ at 3 hr post-injection for the 1B4M conjugate, indicating that the metabolite is rapidly excreted through the biliary system. in contrast to DTPA conjugate, the small $^{111}In-DTPA-like$ metabolite was the major radioindium component (90%) in the liver homogenate as early as 3 hour post-injection, but the cumulative radioindium activity in feces was only 17% at 44 hour, indicating that the metabolite from DTPA conjugate does not clear readily through the biliary tract. Conclusion: The galactosylation of the MoAb conjugates resulted in higher hepatocyte uptake and enhanced metabolism, compared to those without galactosylation. Metabolism of the MoAb-conjugates is different between compounds radiolabled with different chelators due to different characteristics of radiometabolites generated in the liver.

An Improved Friction Model and Its Implications for the Slip, the Frictional Energy, and the Cornering Force and Moment of Tires

  • Park, K.S.;Oh, C.W.;Kim, T.W.;Jeong, Hyun-Yong;Kim, Y.H.
    • Journal of Mechanical Science and Technology
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    • v.20 no.9
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    • pp.1399-1409
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    • 2006
  • An improved friction model was proposed with consideration of the effect of the sliding speed, the contact pressure and the temperature, and it was implemented into a user subroutine of a commercial FEM code, ABAQUS/Explicit. Then, a smooth tire was simulated for free rolling, driving, braking and cornering situations using the improved friction model and the Coulomb friction model, and the effect of the friction models on the slip, the frictional energy distribution and the cornering force and moment was analyzed. For the free rolling, the driving and the braking situations, the improved friction model and the Coulomb friction model resulted in similar profiles of the slip and the frictional energy distributions although the magnitudes were different. The slips obtained from the simulations were in a good correlation with experimental data. For the cornering situation, the Coulomb friction model with the coefficient of friction of 1 or 2 resulted in lower or higher cornering forces and moments than experimental data. In addition, in contrast to experimental data it did not result in a maximum cornering force and a decrease of the cornering moment for the increase of the speed. However, the improved friction model resulted in similar cornering forces and moments to experimental data, and it resulted in a maximum cornering force and a decrease of the cornering moment for the increase of the speed, showing a good correlation with experimental data.

Measurements of Volatile Organics, Newly Designated Offensive Odorants in Korea in 2008 and 2010: a Case Study on Gutter System (2008년과 2010년 지정 VOC 계열 신규악취성분들에 대한 분포특성 조사: 도심 하수환경 중 빗물받이에 대한 연구)

  • Ahn, Ji-Won;Hong, One-Feel;Lee, Eun-Hee;Kim, Ki-Hyun
    • Journal of Korean Society for Atmospheric Environment
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    • v.26 no.3
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    • pp.305-317
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    • 2010
  • In this research, a total of 11 newly designated offensive odorants in Korea in 2008 and 2010 (styrene (S), toluene (T), p-xylene (p-X), methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), butyl acetate (BuAc), isobutyl alcohol (i-BuAl), propionic acid (PA), butyric acid (BA), isovaleric acid (IA), and valeric acid (VA)) were selected as target compounds and analyzed from two types of gutter system in the urban environment. Because of the environmental significance of these compounds as offensive odorants, the results are meaningful enough to explore their behavior and distribution in the urban environmental systems. In the course of this study, samples were collected three times a day from two different gutter systems representing the wet (W) and dry (D) conditions. A large fraction of volatile organic compounds (VOCs) data fell into method detection limit (MDL) range with exceptions of toluene, p-xylene, and methyl ethyl ketone. In contrast, the results of organic fatty acids were distinguished by the relative dominance of butyric acid and propionic acid over others. If the concentration data of all odorants were converted into odor intensity (OI), the results of aromatics, ketones, acetate, and alcohol groups approached zero level. However, odor intensity of organic fatty acids was noticeably higher with the value of 2.8 (on average) from both W and D system, suggesting their potent roles as odorants in gutter system.

Determining Factors on Small Food Service Business Performance (소상공인 외식서비스업체의 경영성과 요인에 관한 연구)

  • HwangBo, Yun
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.6 no.2
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    • pp.51-73
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    • 2011
  • This study aims to examine factors affecting small food service business performance, which is assumed to be dependent primarily on its outskirt's residents. In contrast to the prior research, this paper measures saveral location traits as a separate service business success factor without including the factor in management factors. The empirical results show that small food service's sales can be determined significantly by business career in entrepreneurs' background features. Secondly, its sales can't be influenced by any psychlogical factors such as a desire of achievement, a propensity of risk taking and locus of control. It is assumed that questions about psychological traits based by the prior research do not suit for small food entrepreneur. Thirdly, qualified product have a significant effect on its sales. Finally, its sales can be significantly impacted by the number of customer chair.

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Ethmoidal Meningoencephalocele Associated with Seizure in a Juvenile Alaskan Malamute

  • Park, Sun-young;Lee, Young-jae;Song, Jin-young;Jeon, Seok-ho;Jeong, Ji-yoon;Kang, Byeong-taek;Kang, Ji-hoon;Chang, Jin-hwa;Chang, Dong-woo
    • Journal of Veterinary Clinics
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    • v.33 no.3
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    • pp.168-171
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    • 2016
  • Signalment: An 8-month-old female Alaskan malamute was presented for progressive cluster seizure disorder. Results: There were no abnormalities on neurological examination, survey radiographs, or blood analysis. Magnetic resonance (MR) imaging and computed tomography revealed extension of the olfactory bulb and frontal lobe into the nasal cavity. They also confirmed abnormal anatomy of the nasal turbinates within the rostral part of the nasal cavity and the absence of a cribriform plate. On T2-weighted and fluid-attenuated inversion recovery images, the herniated brain showed heterogeneous and hyperintense signals consistent with intraparenchymal edema. Transverse MR images showed brain herniation into the right frontal cavity and an asymmetrical lateral ventricle because of a left midline shift. On contrast-enhanced MR images, the protruding brain parenchyma was mildly enhanced. Ethmoidal encephalocele was suspected as the final diagnosis. Despite symptomatic treatment, the dog continued to exhibit seizures and was euthanized. Clinical relevance: Ethmoidal encephalocele is a rare disease in dogs. However, it could be considered as a cause of seizure in young dogs.

Characterization and Evaluation of Worker s Exposure to Airborne Glass Fibers in Glass Wool Manufacturing Industry (유리섬유 단열재 제조업 근로자의 공기중 유리섬유 폭로 특성 및 평가 방법에 관한 연구)

  • 신용철;이광용;박천재;이나루;정동인;오세민
    • Journal of Environmental Health Sciences
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    • v.22 no.2
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    • pp.43-57
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    • 1996
  • To characterize worker's exposure to glass fibers, to find the correlation between airborne total dust concentrations and fiber concentrations and to recommend an appropriate evaluation method for worker's exposure to fibrous dusts in glass wool industry, we carried out this study. Average respirable fiber levels at five factories were 0.013-0.056 f/cc, and fairly below the OSHA PEL, 1 f/cc. A factory showed the lowest airborne fiber level, 0.013 f/cc, which was different significantly from those of other factories of which average fiber concentration was 0.046 f/cc. The cutting and grinding operations of insulation products resulted in higher airborne fiber cocentrations than any other processes(p<0.05). To characterize airborne fiber dimension, fiber length and diamter were determined using phase contrast microscope. The geometric means of airborne fiber lengths were $42-105 \mu m$. One factory had airborne fibers whose length distribution(GM = $105 \mu m$) was different from those of other factories(GM = $42-50 \mu m$). The percentages of respirable fibers less thinner than 3 gm were 38.9-90.9% at four factories, and two factories of them had the higher percentages than others. The findings explain for variation of airborne fiber diameters between factories. On the other hand, between the processes were the difference of fiber-length distributions observed. The cutting and grinding operations showed shorter fiber-length distributions than the fiber forming one. However, fiber-diameter distributions or respirable fiber contents were similar in all processes. The airborne fiber concentrations and the dust concentrations had relatively weak correlation(r=0.25), thus number of fibers couldn't be expected reliably from dust amount. Fiber count is appropriate for assessing accurate exposures and health effects caused by fibrous dusts including glass fibers. Ministry of Labor have established occupational exposure limit to glass fibers as nuisiance dust, but should establish it on the basis of respirable fiber concentration to provide adequate protection for worker's health

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Sclerosing Meningioma : Radiological and Clinical Characteristics of 21 Cases

  • Kang, Ho;Kim, Jin Wook;Se, Young-Bem;Dho, Yun-Sik;Choi, Seung Hong;Park, Sung-Hye
    • Journal of Korean Neurosurgical Society
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    • v.59 no.6
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    • pp.584-589
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    • 2016
  • Objective : A rare subtype of meningioma, sclerosing meningioma is not included in the current World Health Organization classification of meningiomas and is classified into the category of other morphological variation subtypes. Sclerosing meningioma is often misdiagnosed to other non-benign meningioma or malignant neoplasm, so it is important to diagnose sclerosing type correctly. We analyzed the radiological and clinical characteristics of a series of sclerosing meningiomas. Methods : Twenty-one patients who underwent surgery in one institute with a histopathologically proven sclerosing meningioma were included from 2006 to 2014. Eighteen tumors were diagnosed as a pure sclerosing-type meningioma, and 3 as mixed type. Magnetic resonance image was taken for all patients including contrast enhancement image. Computed tomography (CT) scan was taken for 16 patients. One neuroradiologist and 1 neurosurgeon reviewed all images retrospectively. Results : In the all 16 patients with preoperative CT images, higher attenuation was observed in the meningioma than in the brain parenchyma, and calcification was observed in 11 (69%). In 15 of the 21 patients (71%), a distinctive very low signal intensity appeared as a dark color in T2-weighted images. Nine of these 15 tumors (60%) exhibited heterogeneous enhancement, and 6 (40%) exhibited homogeneous enhancement that was unlike the homogeneous enhancing pattern shown by conventional meningiomas. Ten patients had a clear tumor margin without peritumoral edema. Conclusion : Although these peculiar radiological characteristics are not unique to sclerosing meningioma, we believe that they are distinctive features that may be helpful for distinguishing sclerosing meningioma from other subtypes.

Protective effects of Tat-DJ-1 protein against streptozotocin-induced diabetes in a mice model

  • Yeo, Hyeon Ji;Yeo, Eun Ji;Shin, Min Jea;Choi, Yeon Joo;Lee, Chi Hern;Kwon, Hyeok Yil;Kim, Dae Won;Eum, Won Sik;Choi, Soo Young
    • BMB Reports
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    • v.51 no.7
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    • pp.362-367
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    • 2018
  • A major feature of type 1 diabetes mellitus (T1DM) is hyperglycemia and dysfunction of pancreatic ${\beta}$-cells. In a previous study, we have shown that Tat-DJ-1 protein inhibits pancreatic RINm5F ${\beta}$-cell death caused by oxidative stress. In this study, we examined effects of Tat-DJ-1 protein on streptozotocin (STZ)-induced diabetic mice. Wild type (WT) Tat-DJ-1 protein transduced into pancreas where it markedly inhibited pancreatic ${\beta}$-cell destruction and regulated levels of serum parameters including insulin, alkaline phosphatase (ALP), and free fatty acid (FFA) secretion. In addition, transduced WT Tat-DJ-1 protein significantly inhibited the activation of $NF-{\kappa}B$ and MAPK (ERK and p38) expression as well as expression of COX-2 and iNOS in STZ exposed pancreas. In contrast, treatment with C106A mutant Tat-DJ-1 protein showed no protective effects. Collectively, our results indicate that WT Tat-DJ-1 protein can significantly ameliorate pancreatic tissues in STZ-induced diabetes in mice.