• The Korean Journal of Nuclear Medicine Technology
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• v.23 no.2
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• pp.29-37
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• 2019

Purpose DMIDR(Discovery Molecular Imaging Digital Ready, General Electric Healthcare, USA) is a PET/CT scanner designed to allow application of PSF(Point Spread Function), TOF(Time of Flight) and Q.Clear algorithm. Especially, Q.Clear is a reconstruction algorithm which can overcome the limitation of OSEM(Ordered Subset Expectation Maximization) and reduce the image noise based on voxel unit. The aim of this paper is to evaluate the performance of reconstruction algorithms and optimize the algorithm combination to improve the accurate SUV(Standardized Uptake Value) measurement and lesion detectability. Materials and Methods PET phantom was filled with $^{18}F-FDG$ radioactivity concentration ratio of hot to background was in a ratio of 2:1, 4:1 and 8:1. Scan was performed using the NEMA protocols. Scan data was reconstructed using combination of (1)VPFX(VUE point FX(TOF)), (2)VPHD-S(VUE Point HD+PSF), (3)VPFX-S (TOF+PSF), (4)QCHD-S-400((VUE Point HD+Q.Clear(${\beta}-strength$ 400)+PSF), (5)QCFX-S-400(TOF +Q.Clear(${\beta}-strength$ 400)+PSF), (6)QCHD-S-50(VUE Point HD+Q.Clear(${\beta}-strength$ 50)+PSF) and (7)QCFX-S-50(TOF+Q.Clear(${\beta}-strength$ 50)+PSF). CR(Contrast Recovery) and BV(Background Variability) were compared. Also, SNR(Signal to Noise Ratio) and RC(Recovery Coefficient) of counts and SUV were compared respectively. Results VPFX-S showed the highest CR value in sphere size of 10 and 13 mm, and QCFX-S-50 showed the highest value in spheres greater than 17 mm. In comparison of BV and SNR, QCFX-S-400 and QCHD-S-400 showed good results. The results of SUV measurement were proportional to the H/B ratio. RC for SUV is in inverse proportion to the H/B ratio and QCFX-S-50 showed highest value. In addition, reconstruction algorithm of Q.Clear using 400 of ${\beta}-strength$ showed lower value. Conclusion When higher ${\beta}-strength$ was applied Q.Clear showed better image quality by reducing the noise. On the contrary, lower ${\beta}-strength$ was applied Q.Clear showed that sharpness increase and PVE(Partial Volume Effect) decrease, so it is possible to measure SUV based on high RC comparing to conventional reconstruction conditions. An appropriate choice of these reconstruction algorithm can improve the accuracy and lesion detectability. In this reason, it is necessary to optimize the algorithm parameter according to the purpose.

• 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.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.55-59
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• 2010

Purpose: Renal excretion is the main route of FDG clearance in FDG PET/CT scan. Applying optimal method of renal excretion is very important for enhancing image quality and diagnostic accuracy. We evaluated several methods of renal excretion in FDG PET/CT scan. Materials and Methods: Thirty patients with normal renal function were prospectively included. Patients were divided into three group and undergone early and delayed FDG PET/CT scans. (1) Delay group; at 1 hour later of early scan, delayed scan was performed without additional hydration, (2) Hydration group; at 1 hour later of early scan, delayed scan was performed with additional oral hydration (700 mL of water), (3) Lasix group; lasix was administered at the end of early scan and dealyed scan was performed 30 min later. Early and delayed scans were compared to evaluate efficiency of renal excretion. Visual and quantitative analyses were performed by experienced physician and technologist of nuclear medicine. Results: On the visual analysis, renal excretion was the most evident in Lasix group followed by Hydration group. Delay group showed poor renal excretion. On the quantitative analysis, washout rates were $9.2{\pm}20.7%$, $28.1{\pm}22.8%$ and $29.5{\pm}23.1%$ for Delay, Hydration and Lasix groups, respectively. Conclusion: Administration of lasix was the best method for enhancing renal excretion. Delayed scan with hydration was also efficient method, but delayed scan without hydration was not adequate method.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.83-86
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• 2010

Purpose: The Molybdenum which is the raw material of $^{99}Mo$-$^{99m}Tc$ generator (generator) is produced from the nuclear reactor. However, output has dwindled as the two nuclear reactors supplying the bulk of radioactive material-one in Chalk River, Ontario and the other in Petten, the Netherlands-have been closed for repairs or maintenance. This resulted in the enhancement of its price. Therefore we have tried to seek the new method which could run generator to increase activity of $^{99m}Tc$ in this study. Materials and Methods: The $^{99m}Tc$ activity obtained from 5 times elution for 5 days from Monday to Friday using two generators was compared with 10 times elution. Appearance test, pH test, LAL test, sterility test, chemical impurity(Al) test, radio chemical purity test, ratio of $^{99}Mo$/$^{99m}Tc$ activity test have been done to check the stability of $^{99m}Tc$ eluting from generator respectively. Results: The $^{99m}Tc$ activity obtained from 5 times elution for 5 days was 168.2 GBq (4545 mCi) and 10 times was 230.5 GBq (6230 mCi). All quality control tests were within normal limit. Conclusion: We got to know that 2 times elution a day obtained more $^{99m}Tc$ activity than one time elution in this study.

• Food Science and Preservation
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• v.13 no.3
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• pp.292-298
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• 2006

Effect of gamma irradiation on the microbiological and physicochemical characteristics of steamed waxy corns was determined in order to develop preservation techniques to enhance shelf-life during storage at room or low temperature. The initial total microbial count, and yeast & molds steamed waxy corns before irradiation were $2.1{\times}10^3CFU/g,\;1.9{\times}10^3CFU/g$, respectively. However, the total microbial count were completely inactivated and the count of yeast and molds were only 34 CFU/g at 3 kGy treatment When non-irradiated steamed waxy corns were stored at $25^{\circ}C$ for 7 months, the growth of total microbial counts and yeasts & molds were rapidly increased up to $7.1{\times}10^6CFU/g\;and\;1.9{\times}10^7CFU/g$, respectively. However, the total microbial counts at 3 kGy treatment and yeast & molds at 5 kGy treatment for 7 month storage were completely inactivated Similar result was observed at $15^{\circ}C$ and $4^{\circ}C$ storage. The Hardness of the irradiated steamed waxy corns and irradiation dose were not significantly different from those of the non-irradiated steamed waxy corns before storage, but the hardness of non-irradiated steamed waxy corns was significantly increased during the storage, compared to those of irradiated corns. The water content of both irradiated and non-irradiated steamed waxy corns after 7 month storage were significantly decreased from $65{\sim}60%$ to 30% but the changes of water content among treatments or irradiation doses were not significantly different during storage. Sugar contents in the irradiated steamed waxy corns were less free than those of non-irradiated samples and the amount of free sugar slowly increased as storage temperature increased. Sensory evaluation result showed that total sensory scores in irradiated steamed waxy corns were better than those of non-irradiated samples and total sensory scores were increased as irradiation doses increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.1
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• pp.110-115
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• 2011

Shelf-life of brined baechu cabbage was extended by pasteurization at $65^{\circ}C$ for 30 min. Starters (Leu. citreum and Lab. plantarum) were added to the pasteurized brined cabbage to supply beneficial lactic acid bacteria during kimchi fermentation. Control kimchis made with baechu cabbage without pasteurization and no addition of the starters to the pasteurized cabbage kimchi were also prepared. The fermentation characteristics and health functionalities of DPPH free radical scavenging activities and in vitro anticancer effects in AGS human gastric cancer cells were compared. The pasteurized brined cabbage could not be fermented well and the functionalities were also low; however, the addition of starter(s), especially mixed starters of Leu. citreum and Lab. plantarum to the pasteurized brined cabbage, significantly increased the counts of lactic acid bacteria, hardness (texture) and overall acceptability in sensory evaluation. The free radical scavenging activities and the anticancer effects were also increased. The fermentation patterns of starter added kimchi prepared with pasteurized brined cabbage were similar to those of naturally fermented kimchi. It seemed that growth of lactic acid bacteria during kimchi fermentation contributed to increased taste and health functionality of kimchi.

• The korean journal of orthodontics
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• v.32 no.2 s.91
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• pp.79-89
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• 2002

The purpose of this study is to evaluate the reproducibility and errors in landmark identification of conventional lateral cephalometric radiography and digital lateral cephalometric radiography. Fifteen conventional lateral cephalometric radiographs and fifteen digital lateral cephalometric radiographs were selected in adults with no considerations on sex and craniofacial forms. Each landmark was identified and expressed as the coordinate (x, y). The landmarks were classified into 3 groups. The landmarks of the first identification was T1, identification after one week was T2, and identification after one month was T3. The mean and standard deviation of identification errors between replicates were calculated according to the x and y coordinates. The errors between first identification and second identification were expressed as T2-T1(x), T2-T1(y) and those between first identification and third identification were expressed as T3-T1(x), T2-T1(y). Each was divided into conventional lateral cephalometric radiography and digital lateral cephalometric radiography. The independent t- test was used for statistical analysis of identification errors for the evaluation of reproducibility. The results of this study were as follows ; 1. Generally, the mean and standard deviation of landmark identification errors in digital lateral cephalometric radiography was smaller than those of conventional lateral cephalometric radiography. 2. Only a few landmarks showed statistically significant difference in identification error between conventional lateral cephalometric radiography and digital lateral cephalometric radiography. 3. The enhancement of image quality didn't guarantee decrease in landmark identification error and didn't affect tendency of landmark identification error.

• Food Science of Animal Resources
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• v.26 no.2
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• pp.166-174
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• 2006

To determine the proper processing and storage conditions, physico-chemical, microbial and sensory properties of venison jerky under different dry times were measured during storage at $30^{\circ}C$ for 28 days. Samples were dried for 3 hr (T1), 4 hr (T2) and 5 hr (T3) at $75^{\circ}C$ in the smoke chamber, respectively. The pH of T1 was slightly lower than those of T2 and T3 as storage time increased. As dry and storage time increased, TBARS of T2 and T3 were significantly higher (p<0.05) than that of T1. In meat color, $L^*$ values of T3 showed slightly higher than those of T1 and T2, while at values were not clearly tendency by the passage of storage time. $b^*$ values of T2 and T3 were higher than that of T1. The water activity were significantly lower (p<0.05) in ,the order of T3$log_{10}$ CFU/g until 28 days and its number were accepted by sensory evaluation. In conclusions, T2 and T3 showed slightly high overall acceptability and lipid oxidative stability compared to T1 conditions. These results indicated that longer dry time ($4{\sim}5 hr$) of venison jerky would be better characteristics as compared to shorter dry time (3 hr) with increased storage time at $30^{\circ}C$.

• Progress in Medical Physics
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• v.14 no.2
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• pp.131-140
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• 2003

As the importance of accuracy in measurings of 3-D anatomical structures continues to be stressed, an objective and quantitative of assessing image quality and accuracy of 3-D volume-rendered images is required. The purpose of this study was to evaluate the quantitative accuracy of 3-D rendered images obtained with MDCT, scanned at various scanning parameters (scan modes, slice thicknesses and reconstruction slice thickness). Twelve clinically significant points that play an important role for the craniofacial bone in plastic surgery and dentistry were marked on the surface of a dry human skull. The direct distances between the reference points were defined as gold standards to assess the measuring errors of 3-D images. Then, we scanned the specimen with acquisition parameters of 300 mA, In kVp, and 1.0 sec scan time in axial and helical scan modes (pitch 3:1 and 6:1) at 1,25 mm, 2.50 mm, 3.75 mm and 5.00 mm slice thicknesses. We performed 3-D visualizations and distance measurements with volumetric analysis software and statistically evaluated the quantitative accuracy of distance measurements. The accuracy of distance measurements on the 3-D images acquired with 1.25, 2.50, 3,75 and 5.00 mm slice thickness were 48%, 33%, 23%, 14%, respectively, and those of the reconstructed 1.25 mm were 53%, 41%, 43%, 36% respectively. Meanwhile, there were insignificant statistical differences (P-value<0.05) in the accuracy of the distance measurements of 3-D images reconstructed with 1.25 mm thickness. In conclusion, slice thickness, rather than scan mode, influenced the quantitative accuracy of distance measurements in 3-D rendered images with MDCT. The quantitative analysis of distance measurements may be a useful tool for evaluating the accuracy of 3-D rendered images used in diagnosis, surgical planning, and radiotherapeutic treatment.

• Korean journal of food and cookery science
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• v.21 no.3 s.87
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• pp.301-310
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• 2005

The effects of defatted soy flour on the physicochemical characteristics of dough and bread making properties were studied. Defatted soy flour is added to wheat flour for bread-making in order to maximize the use of isoflavones in the soybean. Different particle sizes of both defatted soy flour and wheat flour were prepared by grinding and sievingwith meshes. In the mixograph test, the addition of defatted soy flour to wheat flour increased the requirement for water and decreased the dough development time. Water absorption rates were also investigated to determine the optimum quantity of water for good dough. As the level of defatted soy flour mixed with wheat flour increased, the sedimentation and P.K. values decreased. In comparison with control, the bread made with defatted soy flour especially had a lower specific loaf volume. Specific loaf volume of wheat flour-defatted soy flour bread prepared (Ed- this is an incomplete sentence, it's only a subject clause, and I don't how what you intend to state). In terms of the staling rate and hardness of the wheat flour-defatted soy flour bread, the increased defatted soy flour had a faster staling rate during storage at 5? than at 25? for 5days. From the result of sensory evaluation, wheat flour-defatted soy flour breads containing up to $4\%$ defatted soy flour were rated as being of high quality.