• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.12
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• pp.247-253
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• 2013

The purpose is a comparative evaluation in the DR System according to the dosimetry and image quality of the quantitative and objective via Direct digital radiography, Indirect digital radiography, Image intensifier (Charge Coupled Device type) digital radiography. The experimental method used rando phantom and measured the entrance surface dose. And through using the measured entrance surface dose and then using the PCXMC program were evaluated risk due to irradiation and the effective dose. SNR and NPS and CNR were measured and analyzed by using 21cm acryl phantom. Significance of measured value was evaluated by statistics method. Entrance surface dose, major organ dose, effective dose all of them were measured the lowest rated in direct DR when it is on the basis of direct DR dose, high-dose ratio were measured in I.I DR approximately 1.3 times, indirect DR approximately 2.4 times. Risk in accordance with radiation also was measured same as dose ratio. On the conclusion that SNR measurement result based on direct DR SNR measurements, low-SNR ratio were measured in I.I DR approximately 7.25 times, indirect DR approximately 1.48 times. On the conclusion that CNR measurement result based on direct DR CNR measurements, high-dose ratio were measured in I.I type DR approximately 1.16 tims and low-dose ratio were measured in indirect DR approximately 0.87 times. Therefore Direct DR system using a-selenium sensing element to detect x-ray photon is thought effectively at the examination such as infant to sensitive irradiation and the genital gland. Because quality image is built by low dose. Also when it is necessary that image test requiring many diagnosis information, indirect DR system is thought effectively.

• Journal of radiological science and technology
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• v.31 no.2
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• pp.183-188
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• 2008

Aim of this study is to investigate the feasibility of 2D ion chamber array as a substitute of the water phantom system in a periodic Linac QA. For the feasibility study, a commercial ion chamber matrix was used as a substitute of the water phantom in the measurement for a routine QA beam properties. The device used in this study was the I'm RT MatriXX (Wellhofer Dosimetrie, Germany). The MatriXX consists of a 1,020 vented ion chamber array, arranged in $24{\times}24\;cm^2$ matrix. Each ion chamber has a volume of $0.08\;cm^3$, spacing of 0.762 cm. We investigated dosimetric parameters such as dose symmetry, energy ($TPR_{20,10}$), and absolute dose for comparing with the water phantom data with a Farmer-type ionization chamber (FC65G, Wellhofer Dosimetrie, Germany). For the MatriXX measurements, we used the white polystyrene phantom (${\rho}:\;1.18\;g/cm^3$) and also considered the intrinsic layer (${\rho}:\;1.06\;g/cm^3$, t: 0.36 cm) of MatriXX to be equivalent to water depth. In the preliminary study of geometrical QA using MatriXX, the rotation axis of collimator and half beam junction test were included and compared with film measurements. Regarding the dosimetrical QA, the MatriXX has shown good agreements within ${\pm}1%$ compared to the water phantom measurements. In the geometrical test, the data from MatriXX were comparable with those from the films. In conclusion, the MatriXX is a good substitute for water phantom system and film measurements. In addition, the results indicate that the MatriXX as a cost-effective novel QA tool to reduce time and personnel power.

• Progress in Medical Physics
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• v.25 no.4
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• pp.298-303
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• 2014

In this study, we examine the trends and types of incidents frequently occur during radiation therapy by using the data from the radiation oncology safety information system (ROSIS), according to discovery method explores the development direction of future research accident cause factor control method. This study was carried out analysis of incident data in ROSIS nearly 1163 cases in last 11 years from 2003 to 2013. We categorized into treatment methods, found the time, discoverer of occupations and finding ways to analyze the data. Then, we calculate the percentage and the classification for each item. About 1163 cases of incident cases including the near miss cases, external radiation therapy, brachytherapy and other were 97%, 2% and 1%. In the case was improperly planned dose delivery was 44% (497 cases) which 429 cases (86%) was found before 3 fractions and 13 cases were found after 11 fractions. The investigation was found to be distributed in various a found times. Approximately 42% of found time was during treatment and 29% of patients were found the problem during inspection chart. Occupation to discover the most radiation accidents was the radiation therapist (53%) who works in treatment room. Among 1163 incidence cases, 24% cases were found the accident before the treatment, therefore most of accident were found after of during the treatment (70%, 813 cases). This trend is acquired through ROSIS analysis, is expected to be not significantly different in the case of Korea, so it is necessary more diverse and systematic research for the prevention and early detection by using the ROSIS data.

• Journal of radiological science and technology
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• v.34 no.4
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• pp.271-276
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• 2011

Statistical analysis was performed on the patients who took bone densitometry using Lunar and Hologic equipments for 5 months from January $1^{st}$ 2010 to May $30^{st}$, 2010. Patients consisted of 50 in their 40s, 100 in 50s and 50 in 60s. In addition, the results from bone densitometry were carried out on the same subject with two equipments on the same day. In case of 200 subjects, who received the bone densitometry with two equipments, the average age was 54.5 and 54.4 years old, respectively. There was no difference. The T- score of Lunar equipment was $-1.377{\pm}1.221$ and that of Hologic equipment was $-1.806{\pm}1.123$. The T-score of Lunar equipment was measured higher than that of Hologic equipment. T-test was conducted to determine the equality of the mean of two groups with 200 patients. Since the pvalue was 0.000, the value of bone mineral density was significant in two equipments. Furthermore, the patients, who were diagnosed by Lunar, showed more 'normal' and who were diagnosed by Hologic, showed more osteoporosis, which cartegorized by WHO, such as normal, osteopenia, and osteoporosis. Thus, compared results of bone densitometry on lumbar spine L1 - L4 of four normal people with the same equipment showed that T- score of Lunar equipment was $-0.4{\pm}1.2$, and T- score of Hologic equipment was $-1.1{\pm}1.5$. It showed the higher T- score was measured in Lunar equipment as well. Therefore, the correction factor should be considered to use, since T- scores are different between two equipments.

• Journal of Nutrition and Health
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• v.47 no.6
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• pp.403-415
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• 2014

Purpose: This study was conducted in order to investigate the nutrient and food intake status, and dietary quality in Korean adults according to abdominal obesity based on waist circumference. Methods: We analyzed data from the combined 2010~2012 KNHANES (Korean National Health and Nutrition Examination Survey). The analysis included 6,974 adults aged 40 to 64 years. In this study, according to abdominal obesity based on waist circumference (male ${\geq}$ 90 cm, female ${\geq}$ 85 cm), we classified the subjects into the obesity group (male, n = 775, female, n = 1,113) and control group (male, n = 2,038, female, n = 3,048). The nutrient and food group intake, ND (nutrient density), NAR (nutrient adequacy ratio), MAR (mean adequacy ratio), INQ (index of nutritional quality), DDS (dietary diversity score), and DVS (dietary variety score) were analyzed using data from the 24-recall method. Results: For male, no significant difference in quality index of the diet was observed between the obesity group and the normal group. In female, in diet quality (ND, NAR, and INQ), vitamin $B_2$ (ND, NAR, and INQ) calcium (NAR), phosphorous (ND, INQ) and potassium (ND) of the obesity group was significantly lower than those of the control group. DDS and DVS in the obesity group (3.57, 30.95) were significantly lower than those of the control group (3.68, 32.84) (p = 0.0043, 0.0002). DVS (DVS ${\geq}$ 39.9) showed association with lower risk of waist obesity in a logistic regression model after adjustments for multiple confounding factors including age, education, income, alcohol intake frequency, smoking, physical activity, energy intake, and body mass index (OR: 0.616, 95% CI: 0.420-0.903). Conclusion: In conclusion, females with abdominal obesity had lower micronutrient intake quality, DVS than those of the control group. In Korean females, food intake variety can adversely affect waist circumference.

• Journal of radiological science and technology
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• v.31 no.4
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• pp.401-406
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• 2008

The aim of this study is to evaluate contra-lateral breast (CLB) surface dose in Field-in-Field (FIF) technique for breast conserving surgery patients. For evaluation of surface dose in FIF technique, we have compared with other techniques, which were open fields (Open), metal wedge (MW), and enhanced dynamic wedge (EDW) techniques under same geometrical condition and prescribed dose. The three dimensional treatment planning system was used for dose optimization. For the verification of dose calculation, measurements using MOSFET detectors with Anderson Rando phantom were performed. The measured points for four different techniques were at the depth of 0cm (epidermis) and 0.5cm bolus (dermis), and spacing toward 2cm, 4cm, 6cm, 8cm, 10cm apart from the edge of tangential medial beam. The dose calculations were done in 0.25cm grid resolution by modified Batho method for inhomogeneity correction. In the planning results, the surface doses were differentiated in the range of $19.6{\sim}36.9%$, $33.2{\sim}138.2%$ for MW, $1.0{\sim}7.9%$, $1.6{\sim}37.4%$ for EDW, and for FIF at the depth of epidermis and dermis as compared to Open respectively. In the measurements, the surface doses were differentiated in the range of $11.1{\sim}71%$, $22.9{\sim}161%$ for MW, $4.1{\sim}15.5%$, $8.2{\sim}37.9%$ for EDW, and 4.9% for FIF at the depth of epidermis and dermis as compared to Open respectively. The surface doses were considered as underestimating in the planning calculation as compared to the measurement with MOSFET detectors. Was concluded as the lowest one among the techniques, even if it was compared with Open method. Our conclusion could be stated that the FIF technique could make the optimum dose distribution in Breast target, while effectively reduce the probability of secondary carcinogenesis due to undesirable scattered radiation to contra-lateral breast.

• Journal of radiological science and technology
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• v.32 no.3
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• pp.261-270
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• 2009

The study examined the relationship between the compressed breast thickness and Average Glandular Dose (AGD) among 1,969 outpatients who went through breast X-ray in a university hospital for 10 months from July 1st, 2007 to April 30th, 2008. Then it analyzed the result acquired from 3,900 cases of Cranio-Caudal (CC) view, especially, when the breasts were compressed (13-15daN). The following is the conclusion driven from the relationship analysis. 1. The subjects aged in 40s and 50s were 2,679 out of 3,900 cases and this figure was 68.69% in all. 2. In terms of distribution depending on focus/filter, 41.0% was Mo/Mo, 34.8% was Mo/Rh, and 24.2% was Rh/Rh. 3. In terms of compressed breast thickness depending on focus/filter, the average thickness was 26.91 mm at Mo/Mo, 38.84 mm at Mo/Rh, and 48.80 mm at Rh/Rh. The average thickness of the entire cases was shown to be 36.27 mm. 4. AGD depending on focus/filter was 1.27 mGy at Mo/Mo, 1.55 mGy at Mo/Rh, and 1.42 mGy at Rh/Rh. The average glandular dose of the entire cases was shown to be 1.43 mGy. 5. The relationship of AGD depending on compressed breast thickness at Mo/Mo was y=0.0318x + 0.470 while it was y=0.0206x + 0.709 at Mo/Rh and y=0.0248x + 0.335 at Mo/Rh. It was highly influenced by the compressed breast thickness, however, more variation was detected at Mo/Mo depending on breast thickness.

• Journal of radiological science and technology
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• v.36 no.1
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• pp.11-17
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• 2013

Currently, there are many studies being conducted around the world to reduce exposure dose to radiation for patients to receive medical treatments in a safe environment. We developed and fabricated of this shield that the patients are protected from the radiation and are need of safety control during breast imaging. In this study, for breast imaging, GE Senography 2000D were used and set at SID 65cm, 28kVp, and 63mAs. The measuring instrument was Fluke's Victoreen 6000-529. And we performed Face Block on with 30 patients. The chamber on the actual thyroid glands to take CC and MLO and measure the dosage before and after wearing the Face Block. For the results, after wearing the Face Block, exposure was decreased by 53.8%-100% and 65.8% in average in CC View and by 50%-100% and 60.7% in average in MLO View. The development of the Face Block that practically decreased the exposure dose of thyroid glands, crystalline eyes during breast imaging and reduced the patients' anxiety during breast imaging. The Face Block is expected to improve patients' satisfaction and contribute to reducing patients' exposure dose, but more efforts should be made to reduce exposure dose to medical radiation.

• Journal of the Korean Society of Radiology
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• v.5 no.4
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• pp.171-178
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• 2011

To investigate the decrease of BMD by age and the risk factor of osteoporosis in Korean men. We describe the study of a five-years retrospective observational study with male patients. Eighty Korean men who visited hospital for health screening were assessed for this study from 2002 to 2006. We evaluated the BMD of the femoral neck and L-spine, and the preferences and habits in the life. The data were collected for 5 years, and we analysed the five-years change of BMD and the relations between BMD and other factors. Subjects were divided into 3 group by 1st assessment of femoral neck BMD, and were compared with each other. The age of subjects was $43.15{\pm}4.82$ and BMD of femoral neck was $-0.61{\pm}0.97$ and BMD of L-spine was $-0.67{\pm}1.10$ in the first year assessment. The femoral neck BMD of 4th and 5th assessment was decreased significantly compared to that of 1st assessment. The L-spine BMD of 2nd assessment was decreased significantly compared to the 1st assessment. There was no significant correlation between the changes of BMD and preferences or habits-drinking, smoking, eating habit, exercise. The femoral neck BMD of 5th assessment was decreased significantly compared to that of 1st assessment in the high femoral neck BMD group. And there was no significant change of femoral BMD and L-spine BMD in other groups. Low BMD group in the 1st assessment showed lowest BMD in the 5th assessment and high BMD group in the 1st assessment showed highest BMD in the 5th assessment. We can guess that the young men who has low BMD could have high risk of osteoporosis when he became older. And the femoral BMD should be considered important in anticipating the changes of BMD in middle aged men.

• Journal of Radiation Protection and Research
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• v.47 no.4
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• pp.195-203
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• 2022

Background: The aim of the present study was to determine radioactive concentrations in fertilizers known to contain essential nutrients. Results of this study could be used as basic data to monitor the impact of chemical fertilizers on the environment and public health. Nitrogen fertilizers, calcium fertilizers, sulfur fertilizers, phosphate acid fertilizers, and potassium chloride fertilizers were used in this study. Materials and Methods: Five chemical fertilizers were pulverized, placed in polyethylene containers, and weighed. The time to measure each specimen was set to be 3,600 seconds for a scintillator-based gamma-ray spectroscopy system. Concentration of gamma radionuclide was analyzed based on obtained spectra. At the end of the measurement, the spectrum file was stored and used to calculate radioactive concentrations using a gamma-ray spectrometer software. Results and Discussion: In the nitrogen fertilizer, 3.49 ± 5.71 Bq/kg of ¹³⁷Cs, 34.43 ± 7.61 Bq/kg of ¹³⁴Cs, and 569.16 ± 91.15 of ⁴⁰K were detected whereas ¹³¹I was not detected. In the calcium fertilizer, 5.74 ± 4.40 Bq/kg of ¹³⁷Cs (the highest concentration among all fertilizers), 22.37 ± 5.39 Bq/kg of ¹³⁴Cs, and 433.67 ± 64.24 Bq/kg of ⁴⁰K were detected whereas ¹³¹I was not detected. In the sulfur fertilizer, 347.31 ± 55.73 Bq/kg of ⁴⁰K, 19.42 ± 4.53 Bq/kg of ¹³⁴Cs, 2.21 ± 3.49 of ¹³⁷Cs, and 0.04 ± 0.22 Bq/Kg of ¹³¹I were detected. In the phosphoric acid fertilizer, 70,007.34 ± 844.18 Bq/kg of ⁴⁰K (the highest concentration among all fertilizers) and 46.07 ± 70.40 Bq/kg of ¹³⁴Cs were detected whereas neither ¹³⁷Cs nor ¹³¹I was detected. In the potassium chloride fertilizer, 12,827.92 ± 1542.19 Bq/kg of ⁴⁰K was and 94.76 ± 128.79 Bq/kg of ¹³⁴Cs were detected whereas neither ¹³⁷Cs nor ¹³¹I was detected. The present study examined inorganic fertilizers produced by a single manufacturer. There might be different results according to the country and area from which fertilizers are imported. Further studies about inorganic fertilizers in more detail are needed to create measures to reduce ⁴⁰K. Conclusion: Measures are needed to reduce radiation exposure to ⁴⁰K contained in fertilizers including phosphoric acid and potassium chloride fertilizers.