• Journal of Biomedical Engineering Research
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• v.25 no.4
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• pp.253-259
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• 2004

in this study, we developed a Monte Carlo imaging simulation code written by the visual C$\^$++/ programing language for design optimization of a digital X-ray imaging system. As a digital X-ray imaging system, we considered a Gd$_2$O$_2$S(Tb) scintillator and a photosensor array, and included a 2D parallel grid to simulate general test renditions. The interactions between X-ray beams and the system structure, the behavior of lights generated in the scintillator, and their collection in the photosensor array were simulated by using the Monte Carlo method. The scintillator thickness and the photosensor array pitch were assumed to 66$\mu\textrm{m}$ and 48$\mu\textrm{m}$, respertively, and the pixel format was set to 256 x 256. Using the code, we obtained X-ray images under various simulation conditions, and evaluated their image qualities through the calculations of SNR (signal-to-noise ratio), MTF (modulation transfer function), NPS (noise power spectrum), DQE (detective quantum efficiency). The image simulation code developed in this study can be applied effectively for a variety of digital X-ray imaging systems for their design optimization on various design parameters.

• Journal of Sasang Constitutional Medicine
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• v.11 no.1
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• pp.137-157
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• 1999

The purpose of this study is to help classifying Sasang Constitution through correlation with sound characteristic. This study was done it under the suppose that Sasang Constitution has correlation with sound spectrogram. The following result were obtained about correlation between sound spectrogram and Sasang Constitution by comparison and analysis 1. Soeumin answered his voice low tone, smooth and quiet in the survey. Soyangin answered his voice high, clear, fast and speaking random. Taeumin answered his voice low, thick and muddy. 2. Taeyangin was significantly slow compared with the others in the time of reading composition. Taeyangin was significantly slow compared with the others in Formant frequency 1. Taeyangin was significantly discriminated from Soeumin in Formant frequency 5. Taeyangin was significantly low compared with the others in Bandwidth 2. Soeumln was significantly low compared with Taeyangin in Pitch Maximum and Pitch Maximum-Pitch Minimum. Taeyangin was significantly high compared with the others in Energy mean. 3. In list of specification, the discrimination rate was higher than that by lists of 13 in the results of Multi-dimensional 4-class minimum-distance. The discrimination rate of three disposition except Soyangin was higher than that of four disposition in the results of One way ANOVA and Analysis of dis crimination in SPSS/PC+. In CART, the estimate rate of Sasang Constitution discrimination was higher than any other method. It is considered that there is a correlation between sound spectrogram and Sasang constitution according to the results. And method of Sasang constitution classification through sound spectrogram analysis can be one method as assistant for the objectification of Sasang constitution classification.

• Journal of the Korean Arthroscopy Society
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• v.17 no.1
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• pp.24-30
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• 2013

Purpose: To evaluate the outcome of arthroscopic posterior cruciate ligament (PCL) augmentation using an autogenous hamstring tendon graft and the posterior-posterior triangulation technique with preservation of ligament remnant or elongated ligament. Materials and Methods: From January 2002 to December 2009, we performed PCL augmentation using an autogenous hamstring tendon graft and the posterior-posterior triangulation technique in 32 patients. The mean age was 35.2 years. Twenty two cases were male and 10 cases were female. Average follow-up period was 5 years and 5 months (range: 2-7.9). Subjective and objective parameters were utilized in analyses, such as the mean range of motion, post. drawer test, Lysholm knee score, Tegner activity score, International Knee Documentation Cominittee (IKDC) grade, and second look arthroscopic examination. Results: At last follow up posterior displacement by the Telos stress test decreased from $10.8{\pm}5.1\;mm$ to $2.8{\pm}3.7\;mm$ (p<0.05). The final Lysholm knee score improved from $60.4{\pm}5.8$ to $84.6{\pm}4.8$. Tegner activity score improved from 3.2 to 4.8. The final IKDC grade was A in 18, B in 11, C in 3. Postoperative Lysholm knee score, IKDC grades, Tegner activity scale, and posterior displacement demonstrated statistically significant improvement compared to the preoperative state (p<0.05). Conclusion: Arthroscopic PCL reconstruction using an autogenous hamstring tendon with preservation of ligament remnant showed a good clinical results and posterior stability.

• Progress in Medical Physics
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• v.22 no.2
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• pp.99-105
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• 2011

The purpose of this study is to evaluate the accuracy of IMRT in our clinic from based on TG119 procedure and establish action level. Five IMRT test cases were described in TG119: multi-target, head&neck, prostate, and two C-shapes (easy&hard). There were used and delivered to water-equivalent solid phantom for IMRT. Absolute dose for points in target and OAR was measured by using an ion chamber (CC13, IBA). EBT2 film was utilized to compare the measured two-dimensional dose distribution with the calculated one by treatment planning system. All collected data were analyzed using the TG119 specifications to determine the confidence limit. The mean of relative error (%) between measured and calculated value was $1.2{\pm}1.1%$ and $1.2{\pm}0.7%$ for target and OAR, respectively. The resulting confidence limits were 3.4% and 2.6%. In EBT2 film dosimetry, the average percentage of points passing the gamma criteria (3%/3 mm) was $97.7{\pm}0.8%$. Confidence limit values determined by EBT2 film analysis was 3.9%. This study has focused on IMRT commissioning and quality assurance based on TG119 guideline. It is concluded that action level were ${\pm}4%$ and ${\pm}3%$ for target and OAR and 97% for film measurement, respectively. It is expected that TG119-based procedure can be used as reference to evaluate the accuracy of IMRT for each institution.

• Tuberculosis and Respiratory Diseases
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• v.49 no.1
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• pp.82-92
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• 2000

Background : In chronic airway disease, mucus secretion is increased, but extraction of mucin, which is the main component of mucus secretion, is a very complicated and limited in clinical use. Recently, monoclonal antibody for mucin was developed for possible clinical use. In this study, cellular analysis and quantification of respiratory mucin in sputum of patients with chronic airway diseases were performed. Method : Sputum was collected from patients with asthma(n=33), bronchiectasis(n=8) or chronic bronchitis (n=13) by spontaneous expectoration or by hypertonic saline induction. Collected sputums was treated by 0.1% dithiotreitol to dissociate the disulfide bond of the mucus and filtered through a nylon gauze. Total cell count, viability and differential count were measured. For detection of mucin, collected samples were treated with sodium dodecyl sulfate polyacrylamide gel electrophoresis and then with monoclonal antibody(HMO2), as the primary antibody, and PAS stain. The amount of mucin was measured with ELISA by HMO2. Correlation with clinical information, cellular analysis, and amount of measured mucin were analyzed. Results : Total cell counts of sputum were significantly increased in patients with bronchiectasis but viability remained the same. Eosinophils were significantly increased in patients with asthma, neutrophils in bronchiectasis chronic bronchitis, respectively (p<0.05). The results of Western blotting and PAS staining confirmed the presence of glycoproteins and matched? with mucin. The amounts of mucin measured by ELISA were not significantly different among the disease groups. Significant correlation was identified between the amount of mucin and viability(r=-0.482, p<0.05). Conclusion : Inflammatory cells in the sputum of those with chronic airway disease were different for each disease type. Measurement of mucin by ELISA via monoclonal antibodies may be a simple method for the evaluation of chronic airway disease.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.2
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• pp.100-106
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• 2009

Purpose: The study was to assess I-123-N-(3-iodopropen-2-yl)-2[beta]-carbomethoxy-3[beta]-(4-cholorophenyl) tropane(IPT) SPECT in differential diagnosis among early stage of Parkinson's disease(PD) and essential tremor(ET) and normal control(NL) groups quantitatively. Materials and Methods: I-123 IPT brain SPECT of 50 NL, 20 early PD, 30 advanced PD, and 20 ET were performed at 20 minutes and 2 hours. Specific/nonspecific binding of striatum was calculated by using right and left striatal specific to occipital non-specific uptake ratio(striatum-OCC/OCC). Results: Mean value of specific/nonspecific binding ratio was significantly different between advanced PD group and NL group. However, significant overlap of striatal specific/nonspecific binding ratio was observed between PD group and ET group. Bilateral striatal specific/nonspecific binding ratios were decreased in advanced PD. Lateralized differences in the striatal uptake of I-123 IPT correlated with asymmetry in clinical findings in PD group. Conclusion: I-123 IPT SPECT may be a useful method for the diagnosis of PD and objective evaluation of progress of clinical stages. Care should be made in the differential diagnosis of early stage of PD and other motor disturbances mimicking PD such as ET in view of significant overlap in striatal I-123 specific/nonspecific binding ratio.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.2
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• pp.37-43
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• 2013

Purpose: PET/CT scan using the SUV (Standardized Uptake Value) of radiopharmaceutical uptake in organs and tissues as an objective indicator makes it possible to analyze physiological and chemical reactions of human organs. This study analyzes the change of the SUV uptake in accordance with the way how PET/CT patients take a rest after the injection of $^{18}F-FDG$ (Fluororo-deoxyglucose). And also subjective satisfaction is assessed listening to music while taking a rest. Materials and Methods: From April 2011 until February 2013, Among the Primary cancer patients who admitted to the Catholic Medical Center (Seoul & Bucheon St. Mary's Hospital) and scanned $^{18}F-FDG$ PET/CT and also received care through the tracking test (mean age $55.61{\pm}12.41$ years, 108 people, 48 men and 60 women) were selected. The patients were divided into two groups. The first group (A: basal study) is requested to take a rest in bed quietly after the injection. However the second one (B: follow up study) is requested to listen to the music while taking a rest. And then SUV analysis was performed respectively. At the end of the scan, ROI (Region Of Interest) were set from the center of the liver (right lobe) and 3 spots of the brain (frontal, temporal, and occipital lobes). And the SUV was calculated. To identify the correlation among those ROIs, paired t-test was performed using SPSS software (Version 12.0K for windows, P>0.05). Also, after the PET/CT scan the satisfaction study was conducted of all the patients. 1:1 questionnaire survey was performed, and that questionnaire was made using the Likert 5-point scale. By utilizing those questionnaires, the analysis about simple frequency, percentage, average, and standard deviation was performed. Results: The SUV change of the 4 designated ROIs in accordance with listening to music was not statistically significant. (Frontal lobe P-value=0.611, Occipital lobe P-value=0.499, Temporal lobe P-value=0.717, Liver P-value=0.334: P-value>0.05) And the satisfaction study indicated that group B was appear to be 0.42 points (5 basis points) higher than group A. It showed that patients are more satisfied in group B than group A. Conclusion: when performing PET/CT scan using $^{18}F-FDG$, listening to music after the injection of the radiopharmaceuticals does not affect the SUV but given the state of the psychological comfort that may increase the patient's satisfaction.

• Journal of the Korean Arthroscopy Society
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• v.11 no.2
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• pp.104-110
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• 2007

Purpose: The purpose of this study is comparison of clinical outcomes in ACL reconstruction between auto-hamstring tendon and allo-tibialis anterior tendon. Materials and Methods: In this prospective study, we included 60 subjects who underwent ACL reconstruction using 30 hamstring autograft(mainly, national health insurance) and 30 tibialis anterior allograft(including MVA and industrial injuries) between May 2003 and June 2005 by a single surgeon, with a minimum follow-up of 12 months. Outcome measurements were the range of motion, the Lachman test, the IKDC score, the Lysholm score, KT-1000 arthrometer and one-leg hop test. Results: For all the cases, the range of motion was above 135 degrees. The Lachman test, KT-1000 arthrometer and one-leg hop test showed no significant difference between two groups. The IKDC score of auto-hamstring group($87.840{\pm}2.106$) was significantly higher than that of allo-tibialis anterior group($85.273{\pm}2.782$). The Lysholm score of auto-hamstring group($88.067{\pm}2.586$) was also significantly higher than that of allo-tibialis anterior group($85.300{\pm}3.030$). Conclusion: The results of ACL reconstruction using the auto-hamstring tendon and allo-tibialis anterior tendon showed no significant difference in objective items but auto-hamstring group showed better results in subjective scoring. This difference may result from individual factors such as economic problem, secondary gain.

• Journal of Hospice and Palliative Care
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• v.14 no.1
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• pp.28-33
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• 2011

Purpose: Recognition of impending death is crucial not only for efficient communication with the caregiver of the patient, but also determination of the time to refer to a separate room. Current studies simply list the events 'that have already occurred' around 48 hours before the death. This study is to analyze the predictability of each event by comparing the time length from 'change' to death. Methods: Subjects included 160 patients who passed away in a palliative care unit in Incheon. The analysis was limited to 80 patients who had medical records for the last week of their lives. We determined 9 symptoms and 8 signs, and established the standard of 'significant change' of each event before death. Results: The most common symptom was increased sleeping (53.8%) and the most common sign was decreased blood pressure (BP) (87.5%). The mean time to death within 48 hours was 46.8% in the case of resting dyspnea, 13.6% in the ease of low oxygen saturation, and 36.9% in the case of decreased BP. The symptom(s) which had the highest positive predictive value (PV) for death within 48 hours was shown to be resting dyspnea (83%), whereas the combination of resting dyspnea and confusion/delirium (65%) had the highest negative PV. As for the most common signs before death within 48 hours, the positive PVs were more than 95%, and the negative PV was the highest when decreased BP and low oxygen saturation were combined. The difference in survival patterns between symptoms and signs was significant. Conclusion: The most reliable symptoms to predict the impending death are resting dyspnea and confusion/delirium, and decline of oxygen saturation and BP are the reliable signs to predict the event.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.127-132
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• 2010

Purpose: Because of limitation of image acquisition method and acquisition time, scatter correction cannot perform easily in SPECT study. But in our hospital, could provide to clinic doctor of scatter corrected images, through introduction of new generation gamma camera has function of simple scatter correction. Taking this opportunity, we will compare scatter corrected and non-scatter corrected image from image quality of point of view. Materials and Methods: We acquisite the 'Hoffman brain phantom' SPECT image and '1mm line phantom' SPECT image, each 18 times, with GE Infinia Hawkeye 4, SPECT-CT gamma camera. At first, we calculated each contrast from axial slice of scatter corrected and non-scatter corrected SPECT image of 'Hoffman brain phantom'. and next, calculated each FWHM of horizontal and vertical from axial slice of scatter corrected and non-scatter corrected SPECT image of '1mm line phantom'. After then, we attempted T test analysis with SAS program on data, contrast and resolution value of scatter corrected and non-scatter corrected image. Results: The contrast of scatter corrected image, elevated from 0.3979 to 0.3509. And the resolution of scatter corrected image, elevated from 3.4822 to 3.6375. p value were 0.0097 in contrast and <0.0001 in resolution. We knew the fact that do improve of contrast and resolution through scatter correction. Conclusion: We got the improved SPECT image through simple and easy way, scatter correct. We will expect to provide improved images, from contrast and resolution point of view. to our clinic doctor.