• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.3
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• pp.279-286
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• 2009

This study carried out to find out feed value of barley plus pea mixture with different ratio and cutting date to got basic information when introduced the mixture as new cropping system in middle part of Korean peninsular. Dry matter (DM) yield increased as barley seeding rate was higher and showed the highest yield in the plots with barley 85% plus 15% ratio when harvested on May 16. There was no different in crude protein, available protein and digestible protein cutting on April 25 in every mixture, but the content increased with higher pea mixture rate after May 2. The content of acid detergent fiber (ADF) and neutral detergent fiber (NDF) increase coincided with higher barley rate and late cutting dates. But relative feed value (RFV) resulted in opposite trend. Higher pea ratio influenced increased content of total digestible nuterients (TDN), but decreased before May 9 cutting and increased after the next cutting regime. There was no statistical difference in P and Mg between sowing rate, but Ca increased at higher pea ratio and P, Ca, K decreased in all plots as harvests were delayed. The content of estimated net energy (ENE), net energy maintenance (NEM) and net energy gain (NEG) significantly increased with higher pea rate and earlier cutting. But net energy lactation (NEL) was no significant differences between seeding rates and cutting dates. In conclusion, mineral yield such as P, Ca, K and Mg showed the highest yield at barley plus pea ratio of 75 : 25 and energy yield of ENE, NEL, NEM, NEG and TDN was the highest at 85 to 15 mixture plots and DM yield, TDN yield, mineral yield such as P, Ca, K and Mg and energy yield of ENE, NEL, NEM, NEG were the highest on each treatment cutting on May 16.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.35-43
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• 2012

Purpose : PET/CT performed CT-based attenuation correction generates the beam hardening artifact by metallic implant. The attenuation correction causes over or underestimate of the area adjacent to metallic hip prosthetic material and change of $^{18}F$-FDG uptake. Also, the image quality and the diagnosability on genitourinary disease are reduced. Therefore, this study will evaluate the usefulness of MAR (Metal Artifact Reduction) algorithm method to improve the image quality on PET/CT. Materials and Methods : PET/CT was performed by fixing hip prosthesis in SPECT/PET phantom. In PET images with and Without MAR algorithm, the Bright streak, Dark streak, Metal region and Background area that appeared on CT were confirmed, and the change of each SUV (standardized uptake value) was analyzed. Also, in 15 patients who underwent total hip arthroplasty, each MAR algorithm and Without MAR algorithm and non attenuation correction was evaluated. Results : In PET image Without MAR algorithm, SUV of Bright streak region was $0.98{\pm}0.48$ g/ml; Dark streak region was $0.88{\pm}0.02$ g/ml; Metal region was $0.24{\pm}0.16$ g/ml, Background area was $0.91{\pm}0.18$ g/ml. In SUV of PET image with MAR algorithm, Bright streak region was $0.88{\pm}0.49$ g/ml, Dark streak region was $0.63{\pm}0.21$ g/ml, Metal region was $0.06{\pm}0.07$ g/ml, Background was $0.90{\pm}0.02$ g/ml. SUV generally decreased when applying MAR algorithm. In PET image Without MAR algorithm, SUVs of Bright region were higher than those measured in the Background, and it was false positive uptake. But, in PET image with MAR algorithm, SUVs of Bright region were similar to the Background, and false positive uptake disappeared. Conclusion : MAR algorithm could reduce an increase of $^{18}F$-FDG uptake due to attenuation correction in the hip surrounding tissue. However, decrease of SUV in Dark streak region should be considered in the future. Therefore, this study propose that the diagnostic accuracy can be improved in genitourinary diseases adjacent to metallic hip prosthesis, if provided PET images with and Without MAR algorithm, and non attenuation correction images at the same time.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.120-125
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• 2012

Purpose : The purpose of this study was to compare count between Chang's method and CT-based attenuation correction (AC-CT) among the attenuation correction (AC) methods for non-attenuation correction (AC-non) images of Brain SPECT (Single Photon Emission Computed Tomography). Materials and Methods : We injected $^{99m}Tc$ 37Mbq in a Hoffman 3D phantom filled with distilled water in the phantom study, and injected intravenously $^{99m}Tc$-HMPAO 740Mbq in a normal volunteer in the patient study, and then obtained Brain SPECT images with Symbia T6 of Siemens and conducted quantitative brain analysis. Transverse images to which each method was applied were rebuilt at the same position, and 6 regions of interest (ROI) were drawn on each of Slice No. 10, 20 and 30 and then the counts of AC-non, AC-CT and Chang's method were compared. Results : The mean counts of AC-non, AC-CT and Chang's method were $4606.8{\pm}511.3$, $16794.6{\pm}2429.4$, and $8752.6{\pm}896.5$, respectively, in the phantom study and $5460.8{\pm}519.6$, $15320{\pm}1171.6$ and $12795{\pm}1422.1$, respectively, in the patient study. In the phantom study, the ratio of AC-CT to AC-non was 3.70 and the ratio of Chang's method to AC-non was 1.92, and in the patient study, they were 2.85 and 2.38, respectively. Conclusion : From this study, we found that AC-CT makes higher AC than Chang's method. In addition, when Chang's method was used, AC in the patient study was higher than that in the phantom study. These results need to be considered also in other examinations.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.81-86
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• 2012

Purpose : Combined MR/PET scanners that use the MRI for PET AC face the challenge of absent surface coils in MR images and thus cannot directly account for attenuation in the coils. To make up for the weak point of MR attenuation correction, Three Modality System (PET/CT +MR) were used in Severance hospital. The goal of this work was to investigate the effects of MR Torso Coil on CT attenuation correction for PET. Materials and Methods : PET artifacts were evaluated when the MR Torso Coil was present of CTAC data with changing various kV and mA in uniformity water phantom and 1994 NEMA cylinderical phantom. They evaluated and compared the following two scenarios: (1) The uniform cylinder phantom and the MR Torso Coil scanned and reconstructed using CT-AC; (2) 1994 NEMA cylinderical phantom and the MR Torso Coil scanned and reconstructed using CT-AC. Results : Streak artifacts were present in CT images containing the MR Torso Coil due to metal components. These artifacts persisted after the CT images were converted for PET-AC. CT scans tended to over-estimate the linear attenuation coefficient when the kV and mA is increasing of the metal components when using conventional methods for converting from CT number. Conclusion : The presence of MR coils during PET/CT scanning can cause subtle artifacts and potentially important quantification errors. Alternative CT techniques that mitigate artifacts should be used to improve AC accuracy. When possible, removing segments of an MR coil prior to the PET/CT exam is recommended. Further, MR coils could be redesigned to reduce artifacts by rearranging placement of the most attenuating materials.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.62-67
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• 2012

Purpose : At this time, the sentinel lymph node mapping using radioisotope and blue dye is preceded for breast cancer patient's sentinel lymph node biopsy. But all patients were applied the same protocol without consideration of physical specific character like the breast sizes and body mass indexes. The purpose of this study is search the optimized scan time in breast sentinel lymphangiography by observing how much the body mass index and breast size influence speed of lymphatic flow. Materials and Methods : The Object of this study was 100 breast cancer patients(Female, 100 persons, average age $50.34{\pm}10.26$ years old)at Severance hospital from October 2011 to December 2011. They were scanned breast sentinel lymphangiography before operation. This study was performed on Forte dual heads gamma camera (Philips Medical Systems, Nederland B.V.). All patients were intra-dermal injected $^{99m}Tc$-Phytate 18.5 MBq, 0.5 ml. For 80 patients, we have scanned without limitation of scan time until the lymphatic flow from the lymph node since injection. We measured how long the lymphatic flow time between departures from injects site and arrival to lymph node using stopwatch. After we calculated patient's Body mass Index and classified as 4 groups. And we measured patient's breast size and classified 3 groups. The modified breast lymphangiography that changing scan time according to comparison study's result was performed on 20 patients and was estimated. Results : The mean scan time as breast size was A group 2.48 minutes, B group 7.69 minutes, C group 10.43 minutes. The mean scan time as body mass index was under weight 1.35 minutes, normal weight 2.56 minutes, slightly over 5.62 minutes, over weighted 5.62 minutes. The success rate of modified breast lymphangiography was 85%. Conclusion : As the Body mass index became higher and breast size became bigger, the total scan time is increased. Based on the obtained information, we designed modified breast lymphangiography protocol. At the cases applying that protocol, most of sentinel lymph nodes were visualized as lymphatic pool. In conclusion, we found that the more success rate in modified protocol considering physical individuality than study carrying out in the same protocol.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.44-48
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• 2012

Purpose : Arm motion can give rise to striking cold artifact on PET/CT. We investigated that evaluation of scatter-limit correction and correct the patient arm motion artifact in Discovery 600 PET/CT. Materials and Methods : To evaluate a radioactivity uptake (Bq/ml) and a standard uptake value (SUV), the scatter limit correction and scatter correction were compared using 1994 NEMA Phantom$^{TM}$ in Discovery 600 PET/CT (GE Healthcare, Mi, We). Arm motion phantom study was involved a central 20 cm diameter cylinder simulating the neck and 2 peripheral 10 cm diameter cylinders simulating arms. The positions of the arms were altered so as to introduce different amounts of misalignment. The evaluation of arm motion phantom study used the radioactivity uptake and SUV in scatter correction and scatter limit correction. Results : The statistical significance of radioactivity uptake and SUV did not show the differences in comparisons of the scatter limit correction and the scatter correction that not show (p<0.05). Radioactivity uptake of the scatter correction was up to 3.1 kBq/ml in the 0.04 kBq/ml. It was approximately 98.7% undervalued in the arm motion phantom study. However, Radioactivity uptake of the scatter limit correction was up to 3.0 kBq/ml in the 2.11 kBq/ml. It was approximately 30% undervalued in arm motion phantom study. SUV of the scatter correction was 1.05 to 0.006 and underestimated about 98%. However, an applying SUV of the scatter limit correction changed the value as 0.67 which is underestimated about 25%. Radioactivity uptake and SUV of the scatter limit correction was increased approximately 60%, or more than the scatter correction. Conclusion : It is considered that if the patient arm motion artifact was occurred the scatter limit correction will be applicable to give an accurate diagnosis.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.1
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• pp.40-46
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• 2009

Purpose: A whole body scan using a radioactive iodine (I-131) for the patients with differentiated thyroid cancer is generally an useful method to detect the remnant thyroid tissue, recurred lesion or metastasis lesion after a surgery. The high dose treatment using the radioactive iodine recently tends to increase, and a hospitalization wait for the treatment has been delayed for several months. In this hospital, the treatable patients per week were increased in number through expanding a water-purifier tank and the examination time also increased as the I-131 whole body scan patients increased. Improvement for this problem, this research reduce the existing examination time and classifying the lesion's exact position intended to by fabricating and utilizing the transmission scan tool and an excellent resolution for whole body imaging. Materials and Methods: After conducting the whole body scan for patients who visited the department from February to July 2008 and received the I-131 whole body scan using the ORBITER Gamma Camera. A rail was installed in the examination table for the transmission scan for show a contour of surface area and then the transmission image was obtained and fused to the whole body scan through fabricating the tool to put a flood phantom of diluted 2 mCi $^{99m}Tc$-pertechnetate. Results: Fused image of I-131 whole body scan and the transmission scan had the excellent resolution to discriminate an oral cavity or salivary gland region, neck region's lesion, and metastasis region's position through a simple marking, and could reduce the examination time of 8~28 minutes because without the additional local image. Conclusions: In I-131 whole body scan, the transmission scan can accurately show a contour of surface area through the attenuation of radioactivity, and is useful to indicate the remnant thyroid tissue or metastasis lesion's position by improving the resolution through the fusion image with alreadyexecuted I-131 whole body scan. Also, because the additional local image is not necessary, it can reduce the time required for the examination. It will extensively apply to other clinical examinations to be helpful for identifying an anatomical position because it shows the contour of surface area.

• Journal of the Korean Society of Radiology
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• v.14 no.5
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• pp.563-575
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• 2020

The purpose of this study is to evaluate the activation characteristics that occur in a linear accelerator for container security inspection. In the computer simulation design, first, the targets consisted of a tungsten (Z=74) single material target and a tungsten (Z=74) and copper (Z=29) composite target. Second, the fan beam collimator was composed of a single material of lead (Z=82) and a composite material of tungsten (Z-74) and lead (Z=82) depending on the material. Final, the concrete in the room where the linear accelerator was located contained magnetite type and impurities. In the research method, first, the optical neutron flux was calculated using the MCNP6 code as a F4 Tally for the linear accelerator and structure. Second, the photoneutron flux calculated from the MCNP6 code was applied to FISPACT-II to evaluate the activation product. Final, the decommissioning evaluation was conducted through the specific activity of the activation product. As a result, first, it was the most common in photoneutron targets, followed by a collimator and a concrete 10 cm deep. Second, activation products were produced as by-products of W-181 in tungsten targets and collimator, and Co-60, Ni-63, Cs-134, Eu-152, Eu-154 nuclides in impurity-containing concrete. Final, it was found that the tungsten target satisfies the permissible concentration for self-disposal after 90 days upon decommissioning. These results could be confirmed that the photoneutron yield and degree of activation at 9 MeV energy were insignificant. However, it is thought that W-181 generated from the tungsten target and collimator of the linear accelerator may affect the exposure when disassembled for repair. Therefore, this study presents basic data on the management of activated parts of a linear accelerator for container security inspection. In addition, When decommissioning the linear accelerator for container security inspection, it is expected that it can be used to prove the standard that permissible concentration of self-disposal.

• Korean Security Journal
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• no.11
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• pp.21-36
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• 2006

This study aims to grasp the general conditions regarding university students in security related majors in Korea. Followings will be covered here: what motivated them to choose those majors, how much are they satisfied with major curriculum course after matriculation, whether they got jobs through the education, what is their consciousness on their majors, jobs, and courses like, and what effects their job preference. And this study also aims at helping the students with their future plans such as admission to a school of higher grade and choosing their job. For this study, we distributed 340 cpoies to the students in security related majors at 4 four-year colleges and 1 two-year college, and collected 298 copies by means of quota sampling method. For collected questionnaires, we used individual T-test verification and one-way ANOVA analysis to grasp the situation. Significance standard for the test results was set as p<0.05. Following are the test results. First, the analysis on students' satisfaction rate resulted in male students' average of 2.42, compared to female students' average of 2.10, which shows female students have higher satisfaction rate in choosing their majors than male students. Secondly, The results on analysis of satisfaction rate on their curriculums, classes, and majors show that students in security-related majors showed different satisfaction rate and different averages according to their sex and the year of the college. The study indicates that males have higher satisfaction rate on curriculum than females, with male students' average of 2.63 and female students' average 2.88. According to the year of the college, there was a significant difference statistically, Statistics show that students at two-year college have higher satisfaction rate than those at four-year college, with two-year college students' average of 2.48 and four-year college students' of 2.74. students have the average of 3.56. The higher year they were in, the more improvement the curriculum required. When it comes to convenience offer for employment, male students expected more from school than female students, with males' average of 2.74 and females' average of 4.07. Male students marked higher than female students in the extent of job information offer, with males' average of 2.96 and females' average of 2.59. Fourthly, when students in security-related majors were surveyed on their consciousness of their future plans such as getting jibs, two-year college students had more certificates of qualification for employment than four-year college students. What they do preponderantly in preparation for employment was studying foreign languages, which took up 40.4%. And when they were asked on their confidence for employment, positive answers were far more than negative ones with the percentage of 39.6%, while negative took up just 14.0%. Fifthly, when it come to the students in security-related students' job preferences, 49.2% preferred safe job conditions in public security area and 34% preferred private guard or private security organizations. And in the public security area, the highest percentage of 28.6 preferred to work in presidential security service. In the area of private security, 21.2% showed interests in private guard and private security organizations.

• Tuberculosis and Respiratory Diseases
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• v.56 no.2
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• pp.159-168
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• 2004

Background : In recent years, numerous human tumor specific antigens such as melanoma antigen gene(MAGE) that is recognized by autologous cytotoxic T lymphocytes have been identified. MAGE is expressed in many human malignancies in various organs, such as lung, breast, stomach, esophagus and leukemia. Therefore MAGE has been studied widely for tumor diagnosis and immunotherapy. But, so far there were no clinical studies evaluating the role of MAGE in pleural effusion. We investigated the expression of MAGE in the patients with exudative pleural effusion for it's diagnostic utility and the results were compared with those of cytologic examinations. Methods : Diagnostic thoracentesis was performed in 44 consecutive patients with exudative pleural effusion during 6 months. We examined the expression of MAGE and cytology with the obtained pleural effusion. Expression of MAGE was interpreted by means of a commercial kit using RT-PCR method. Enrolled patients were divided into two groups such as malignant and benign and we analyzed its' sensitivity and specificity. Results : There were no significant differences between two groups in age, sex, white blood cell counts in pleural fluid, pleural fluid/serum protein ratio and pleural fluid/serum LDH ratio. The sensitivity and specificity of MAGE were 72.2% and 96.2% respectively and the positive predictive value and negative predictive value of MAGE were also 92.9% and 83.3% respectively. The sensitivity and negative predictive value of cytologic examinations were 66.7% and 81.3% respectively. There were no significant differences between sensitivities of MAGE and cytologic examinations but false positive result of MAGE was found in 1 case of tuberculous pleurisy. Conclusion : MAGE is a sensitive and specific marker for the differential diagnosis between benign and malignant effusion in patients with exudative pleural effusion. And MAGE would provide the equal sensitivity compared with that of cytologic examination in patients with malignant pleural effusion if 5mL of the pleural fluid is examined.