• Pediatric Infection and Vaccine
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• v.11 no.1
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• pp.101-111
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• 2004

Purpose : This study was performed to observe the epidemiological pattern of M. pneumoniae pneumonia during the period from 1993 to 2002 and also to see some clinical characteristics of M. pneumoniae pneumonia during recent five years. Methods : We had performed a retrospective analysis of epidemiological pattern of occurrence in 682 patients with M. pneumoniae pneumonia admitted to Department of Pediatrics of Han-il General Hospital from January, 1993 to December, 2002. Results : The annual ratio of M. pneumoniae pneumonia was compared with the total numbers of respiratory tract infection patients. The ratios were 19.1% in 1993, 13.0% in 1994, 5.6% in 1995, 12.8% in 1996, 18.6% in 1997, 22.6% in 1998, 1.1% in 1999, 13.3% in 2000, 9.1% in 2001, 6.0% in 2002, and 19.9% in 2003. The epidemics have occurred in 1993, 1997, 1998, 2000, and 2003 years showing 3~4 year intervals. The peak incidence of age was four to six years old(286 cases; 41.9%) and male-to-female ratio was 1 : 1.1. Monthly distribution showed a high frequency from August to December and the major outbreak occurred in November(119 cases; 17.4%), in October(106 cases; 15.5%), and in December(96 cases; 14.1%) in order of frequency. The most common symptoms were cough (660 cases; 96.8%), fever(569 cases; 83.4%), and sputum(522 cases; 76.5%) in that order. Leukocytosis was observed in 31.2% of patients based on a normal range according to the adjusted age. Increased ESR(${\geq}20mm/hr$) was noted in 42.5% of cases and CRP was positive in 37.8% of cases. On the chest X-ray examination, pulmonary infiltration was noted in 557 cases(81.7%), and the patterns of pneumonic infiltration were bronchopneumonia(78.0%), lobar(35.5%), lobular(19.2%), and interstitial pneumonia(28.7%). Complications were paranasal sinusitis(41 cases), acute otitis media(23 cases), pleural effusion(19 cases). cervical lymphadenitis(18 cases), and glomerulonephritis(1 case). Conclusion : The pattern of M. pneumoniae pneumonia from 1997 to 2003 noted 3~4 year interval with peak monthly distribution of October and November compared with 3 year interval and peak incidence of summer period before 1996.

• Childhood Kidney Diseases
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• v.1 no.2
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• pp.144-150
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• 1997

Purpose : The kidney is one of the most common sites of cyst formation. Cystic diseases of the kidney are a diverse group of clinicopathologic entities and variable prognosis. They span a wide range of both age of presentation and severity of the renal disease. And many of them are systemic disorders, sharing similar process of cyst formation in other organs. Recently, development of imaging studies has been contributing widely to the diagnosis of the diseases. Treatment, however, is not established satisfactorily. We performed this study to evaluate the occurrence and treatment of cystic diseases of the kidney. Methods : We reviewed retrospectively the medical records of 44 patients with cystic diseases of the kidney in the Department of Pediatrics, during last 11 years. Results : In the 44 patients with cystic diseases of the kidney, 31 patients(71%) had multicystic dysplastic kidney and 11(35%) of them received nephrectomy due to differentiation from neoplasms or severe abdominal distension. Seven patients(16%) had polycystic kidney disease, and all of them were infantile type. Five patients(11%) were diagnosed as having a simple renal cysts. Progression to renal failure was noted in none of the cases. In 14(32%) out of total 44 patients, the diagnosis was made in neonatal or infantile pelted. Conclusion : The incidence of cystic diseases of the kidney appeared very low, but further investigation on their pathogenesis, classification, and indication of treatment is needed.

• Childhood Kidney Diseases
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• v.12 no.1
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• pp.62-69
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• 2008

Purpose: The most concerning issue in children with urinary tract infection(UTI) is the probability of underlying genitourinary anomalies and vesicoureteral reflux (VUR), which is frequently associated with renal scarring and eventually end-stage renal disease. Therefore, voiding cystourethrography(VCUG) is usually recommended at the earliest convenient time for children with UTI. However, VCUG is an invasive procedure that requires catheterization and exposure to X-ray. In this study, we aimed to determine the predictability of clinical, laboratory and imaging parameters for VUR in children with UTI. Methods: Data of children with bacteriologically proven UTI who underwent VCUG were evaluated retrospectively for clinical(age, gender, fever), laboratory(leukocytosis, ESR, CRP, pyuria, blood urea nitrogen, serum creatinine) and imaging(renal ultrasound and DMSA renal scan) findings. First, children with UTI were divided into two groups according to the presence of VUR as non-VUR group and with VUR group, and clinical, laboratory variables were compared between these groups. Second, patients who had VUR were reclassified as low-grade VUR(grade I-II) group and high-grade(grade III-V) VUR group according to grading of VUR, and clinical, laboratory and imaging variables were compared between these groups. Results: Among 410 children with UTI, 137 had VUR and 78 high-grade VUR. Fever, leukocytosis, ESR, CRP, pyuria were associated with VUR. In addition, abnormal findings of ultrasonography and DMSA renal scan were closely related to VUR. However, these clinical and laboratory variable in patients with high grade VUR were not different significantly, compared to those with low-grade VUR group. Conclusion: Fever, leukocytosis, ESR, CRP seems to be potentially useful predictors of VUR in pediatric patients with UTI. In addition, renal ultrasonography and DMSA renal scan findings supported the presence of VUR. Further study of these findings could limit unnecessary VCUG in patients with UTI.

• Journal of the Korean Society of Radiology
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• v.11 no.1
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• pp.43-48
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• 2017

Measurement of bone marrow measurements may occur if bone marrow examination performed with bone marrow examination (bone marrow examination) and bone density (bone scan) are performed together recently. Thus, it was examined in clinical aspects that $^{99m}Tc-MDP$ compounds were affected by bone mineral density measurements. The average age of the participants in the experiment was $35.17{\pm}9.45$ and the patient fractures of the lumbar vertebrae that could affect the metabolic disease and bone density measurements affecting the metabolic disease of the 17 subjects. 6 patients with normal bone mineral density T-scores>-1.0 in 12 patients were analyzed before and after the administration of $^{99m}Tc-MDP$. In the lumbar spine, the average of $0.975{\pm}0.084g/cm^2$ and $0.966{\pm}0.078g/cm^2$ were increased by $0.009g/cm^2$. respectively In the right proximal femur, mean values were $0.909{\pm}0.078g/cm^2$ and $0.913{\pm}0.086g/cm^2$. In the right proximal thigh, mean values were $0.909{\pm}0.078g/cm^2$ and $0.913{\pm}0.08 g/cm^2$, respectively, which decreased by $0.004g/cm^2$. In the left side proximal femur, mean $0.887{\pm}0.099g/cm^2$ and $0.881{\pm}0.103g/cm^2$, respectively, increased by $0.007g/cm^2$. Therefore, the BMD changes in the lumbar region were larger than that in the proximal thigh. In addition, $^{99m}Tc-MDP$ did not affect the BMD. And a bone scan test using a technetium-labeled compound emitting a gamma-ray energy of 140 keV did not significantly affect bone density measurements. However, if the nuclear medical examination and the osteoporosis test are to be performed together, the examination should be carried out at intervals considering the exposures of the patient.

• Journal of the Korean Society of Radiology
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• v.14 no.1
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• pp.53-60
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• 2020

The purpose of this study is to identify factors affecting picture quality in Roadmap images, which were studied by varying the dilution rate, collimation field and flow rate of contrast medium. For a quantitative evaluation of the quality of the picture, a 3mm vessel model Water Phantom was self-produced using acrylic, a roadmap image was acquired with a self-produced vascular model Water Phantom, and the SNR(Signal to Noise Ratio) and CNR (Contrast to Noise Ratio) were analyzed. CM:N/S In the study on the change of dilution rate, CM:N/S dilution rate changed to (100%~10%:100%), and the measurement of the roadmap image taken using the vascular model Water Phantom showed that the measurement value of SNR gradually decreased as the N/S dilution rate was increased, and the measurement of CNR was gradually reduced. It was confirmed that the higher the dilution rate of CM:N/S, the lower the SNR and CNR, and also significant image can be obtained at the dilution rate of CM:N/S (100%~70:30%). The study showed the value of SNR and CNR in Roadmap image was increased as the Collimation Field was narrowed to the center of the vascular phantom; the Collimation Field was narrowed to the center of the vessel model by 2cm intervals to 0cm through 12cm. To verify the relationship with Roadmap image and Flow Rate, volume of the autoinjector was kept constant at 15 and the flow rate was gradually increased 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. The value of SNR and CNR of images taken by using water Phantom gradually decreased as the Flow Rate increased, but at Flow Rate 9 and 10, the SNR and CNR value was increase. It was not possible to confirm the relationship with SNR and CNR by ROI mean value and Background mean value. It is considered that further study is needed to evaluate the correlation about Roadmap image and Flow Rate. In conclusion, as the dilution rate of N/S in contrast medium was increased, the value of SNR and CNR was decreased. The narrower the Collimation Field, the higher image quality by increasing value of SNR and CNR. However, it is not confirmed the relationship Roadmap image and Flow Rate. It is considered that appropriate contrast medium concentration to minimize the effects of kidney and proper Collimation Field to improve contrast of image and reduce exposure X-ray during procedure is needed.

• Journal of radiological science and technology
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• v.35 no.4
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• pp.345-352
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• 2012

As the breast cancer rate is increasing fast in Korean women, people pay more attention to mammography and number of mammography have been increasing dramatically over the last few years. Mammography is the only means to diagnose breast cancer early, but harms caused by radiation exposure shouldn't be overlooked. Therefore, it is important to calculate the radiation dose being absorbed into the breast tissue during the process of mammography for a protective measure against radiation exposure. Because it is impossible to directly measure the radiation dose being absorbed into the human body, statistical calculation methods are commonly used, and most of them are supposed to simulate the interaction between radiation and matter by describing the human body internal structure with anthropomorphic phantoms. However, a simulation using Geant4 Code of Monte Carlo Method, which is well-known as most accurate in calculating the absorbed dose inside the human body, helps calculate exact dose by recreating the anatomical human body structure as it is through the DICOM file of CT. To calculate the absorbed dose in the breast tissue, therefore, this study carried out a simulation using Geant4 Code, and by using the DICOM converted file provided by Geant4, this study changed the human body structure expressed on the CT image data into geometry needed for this simulation. Besides, this study attempted to verify if the dose calculation of Geant4 interlocking with the DICOM file is useful, by comparing the calculated dose provided by this simulation and the measured dose provided by the PTW ion chamber. As a result, under the condition of 28kVp/190mAs, the Difference(%) between the measured dose and the calculated dose was found to be 0.08 %~0.33 %, and at 28 kVp/70 mAs, the Difference(%) of dose was 0.01 %~0.16 %, both of which showed results within 2%, the effective difference range. Therefore, this study found out that calculation of the absorbed dose using Geant4 Simulation is useful in measuring the absorbed dose in the breast tissue for mammography.

• Journal of radiological science and technology
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• v.39 no.4
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• pp.577-585
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• 2016

The purpose of this study is to evaluate the accuracy of beam delivery QA software using the MLC dynalog file, about the VMAT plan with AAPM TG-119 protocol. The Clinac iX with a built-in 120 MLC was used to acquire the MLC dynalog file be imported in MobiusFx(MFX). To establish VMAT plan, Oncentra RTP system was used target and organ structures were contoured in Im'RT phantom. For evaluation of dose distribution was evaluated by using gamma index, and the point dose was evaluated by using the CC13 ion chamber in Im'RT phantom. For the evaluation of point dose, the mean of relative error between measured and calculated value was $1.41{\pm}0.92%$(Target) and $0.89{\pm}0.86%$(OAR), the confidence limit were 3.21(96.79%, Target) and 2.58(97.42%, OAR). For the evaluation of dose distribution, in case of $Delta^{4PT}$, the average percentage of passing rate were $99.78{\pm}0.2%$(3%/3 mm), $96.86{\pm}1.76%$(2%/2 mm). In case of MFX, the average percentage of passing rate were $99.90{\pm}0.14%$(3%/3 mm), $97.98{\pm}1.97%$(2%/2 mm), the confidence limits(CL) were in case of $Delta^{4PT}$ 0.62(99.38%, 3%/3 mm), 6.6(93.4%, 2%/2 mm), in case of MFX, 0.38(99.62%, 3%/3 mm), 5.88(94.12%, 2%/2 mm). In this study, we performed VMAT QA method using dynamic MLC log file compare to binary diode array chamber. All analyzed results were satisfied with acceptance criteria based on TG-119 protocol.

• Korean Journal of Weed Science
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• v.9 no.3
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• pp.183-200
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• 1989

An experiment was conducted at the greenhouse of the International Rice Research Institute in 1987 to find out the character of dry matter production, the potential seed production ability and the ecological and physiological strategies to adaptation. For these, two rice cultivars, IR64(lowland rice) and UPLRi-5(upland rice), and seven weed species were used ; Echinochloa glabrescens Munro ex Hook. f., E. cress-galls ssp. hispidula (Retz.) Honda, E. colons (L.) Link, Monochoria vaginalis (Burin. f.), Ludwigia octovalvis Jacq.) Raven, Fimbristylis miliacea Vahl and Cyperus difformis L. Adaptation strategies of weed species varied by species. However, they had efficient seed production strategy through different ways. In general, sedge weed species (F. miliacea and C. difformis) produced great amount of seeds at the expense of seed size through greater ratooning ability and low relative dry weight for flowering. For broadleaved weed species, greater number of descendants were obtained through high plasticity and low relative dry weight for flowering (M. vaginalis) or greater growth ability through effective photosynthetic efficiency (L. octovalvis). Grass weed species, on the other hand, produced their seeds through effective growth (net assimilation rate and relative growth rate), high ratooning ability (except E. crus-galls ssp. hispidula) or low relative dry weight to maximum dry weight for flowering (E. glabrescens). The harvest indices of the weed species were considerably lower than those of rice. Fimbristylis miliacea had the greatest ratooning ability followed by C. difformis, E. colons and E. glabrescens. The greatest seed productivity was recorded by C. difformis (279, 000) and L. octovalvis (268,000) while rice produced the least number of seeds (1300-6100). Log seed weight had a negative linear relationship with log seed number (y=6.30-1.48X, $R=-0.965^{**}$). For all species plant plasticity response was not directly correlated with mortality response.

• The Korean Journal of Nuclear Medicine
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• v.28 no.2
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• pp.186-191
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• 1994

Tc-99m MIBI, a lipophilic cation, was reported as a useful agent for localization of lung cancer. The effect of radiation therapy on the uptake of Tc-99m MIBI in lung cancer, however, was not well evaluated. The aim of the present study was to elucidate the usefulness of Tc-99m MIBI SPECT in the localization and the assessment of radiotherapy in non-small cell lung cancer. Twenty patients(19 males and 1 female, mean age 59, 16 squamous cell ca and 4 adenoca) were studied with Tc-99m MIBI SPECT before radiation therapy. Eleven patients(10 males and 1 female, mean age 59, 8 squamous cell ca and 3 adenoca) were repeated the study 1 month after the completion of radiation therapy(mean dose 6453cGy). All patients showed positive uptakes of Tc-99m MIBI in their tumors. One patient showed a hot uptake in atelectatic area. There was no difference of Tc-99m MIBI uptakes between squamous cell ca and adenoca either on planar or tomographic images. Tc-99m MIBI uptake ratios of squamous cell ca and adenoca were $1.50{\pm}0.16$ and $1.45{\pm}0.15$ on planar images, and $2.73{\pm}0.46$ and $2.54{\pm}0.37$ on tomographic images, respectively. The concordance between radiological change(chest x-ray and CT) and change of Tc-99m MIBI uptakes was 9/11 (81.8% ). In conclusion, Tc-99m MIBI SPECT was useful in the localization of tumor and the assessment of radiation therapy in non-small cell lung cancer.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.121-125
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• 2011

Purpose: The DNA-type virus HBV, discovered by D. Dane and others in 1976, is approximately 42nm big and known as the main cause of liver-related diseases around the world. HBsAg has 4 kinds of subtypes including adw, adr, ayw and ayr and besides common antigen factor a, there are d, y, r, w. From the methods of serologically testing HBV, IRMA, EIA and CLIa were developed for testing HBsAg and are being used in examining the surface antigen of HBV. In this study, among the methods for testing HBV, the recently developed RIAKEY Ultrasensitive HBsAg IRMA kit's sensitivity level and performance in detection of mutant forms were measured and compared with CLIA. Materials and methods: Two certified reference materials, which are WHO 1st International Standard 1985(80/549) and WHO 2nd International Standard 2003(00/588. subtype adw2, genotypeA), were used in the examination and the sensitivity level was measured by diluting these materials from 0.08 IU/ml to 0.005 IU/ml. The materials for examining the detection of mutant forms included 9 kinds of subtype 'ad' and one kind of subtype 'ay' purchased from DSI company. Also, with the use of positive and negative samples, they was compared with CLIA. Result: Ultrasensitive HBsAg kit based on IRMA method showed the detection of up to 0.01 IU/ml not only for WHO 1st International Standard 1985(80/549) but also for WHO 2nd International Standard 2003(00/588. subtype adw2, genotypeA) and the sensitivity level was measured as 0.01 IU/ml by WHO standard. In testing the performance for detection of mutant forms, the 9 kinds of subtype 'ad' and one kind of subtype 'ay' mutant materials were detected, demonstrating the capacity of detecting various types of mutant forms. Conclusions: With the clinical importance of sensitivity level and performance in detection of mutant forms increasing in the field of HBsAg diagnosis, the examination of IRMA's effectiveness using RIA method in the aspects of the sensitivity level and performance in detection of mutant forms was carried out and its result is as follows. The sensitivity level was measured as 0.01 IU/ml by WHO standard and it was possible to measure various types of mutant forms with high sensitivity. Thus it is suggested that more speedy and accurate reports could be produced from a nuclear medicine laboratory for clinical practitioners requiring results of various situations.