• Journal of the Korean Society of Radiology
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• v.14 no.3
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• pp.253-259
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• 2020

Mammography has the advantage of being economical, simple and effective in detecting microcalcification, but breast is a highly sensitive organ and is accompanied by the risk of an over-exposure. While accurate dose assessments are important to prevent this, current breast dose assessments are limited to breast implant patients. This purpose of this study was to identify dose variations due to tube voltages by forming a mock-up with breast implants for an accurate dosimetric assessment on breast implant patients. As a result, doses from the presence of breast implants were smaller than those from the absence of the mammal. As the result of the change of the voltage to 26, 28, 30, and 32 kV, the imcreased tube voltage included larger dose regardless of the presence of Breast implant. Therefore, it is believed that diagnosis recommendations for breast implants will be possible if further studies on internal and external bioretical imaging and quality assessment are carried out as the basis for this study.

• Journal of the Korean Society of Radiology
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• v.9 no.1
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• pp.61-65
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• 2015

Mammography equipment is an essential detector for making an early diagnosis of female's breast lesion. Recently, in most hospitals, a digital mammography detector is used due to the wide and consistent supply of digital mammography equipment. However, the average effective radiation is increasing due to the indiscreet use of CR or DR mammography. The purpose of this study is to recognize the possible indirect radiation damage, which can be occurred due to an excessive effective exposure of radiation, by evaluating spacial radiation rate of the digital mammography detector used for female patient. Consequently, the high mount of spacial radiation showed digital mammography equipment on the horizontal direction. Considering the result, digital mammography equipment should be installed by avoiding along the horizontal direction.

• Journal of the Korean Society of Radiology
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• v.10 no.4
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• pp.271-278
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• 2016

This study was fulfilled to evaluate the absorbed dose of breast and adjacent organs using MIRD type phantom in brachytherapy of breast cancer. The absorbed dose was analyzed assuming left or right breast is source organ which is $^{103}Pd$ or $^{192}Ir$. As a result, $^{192}Ir$ dose is higher than $^{103}Pd$ in source organ and also in contralateral breast. Particularly, significant adjacent organs are lung, liver, heart and contralateral breast in brachytherapy of breast cancer.

• Radiation Oncology Journal
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• v.22 no.3
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• pp.225-233
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• 2004

Purpose: The Ideal breast irradiation method should provide an optimal dose distribution In the treated breast volume and a minimum scatter dose to the nearby normal tissue. Physical wedges have been used to Improve the dose distribution In the treated breast, but unfortunately Introduce an Increased scatter dose outside the treatment yield, pavllculariy to the contralateral breast. The typical physical wedge (FW) was compared with 4he virtual wedge (VW) to do)ermine the difference In the dose distribution affecting on the treated breast and the contralateral breast, lung, heart and surrounding perlpheral soft tissue. Methods and Materials: The data collected consisted of a measurement taken with solid water, a Humanoid Alderson Rando phantom and patients. The radiation doses at the ipsllateral breast and skin, contralateral breast and skin, surrounding peripheral soft tissue, and Ipsllateral lung and heart were compared using the physical wedge and virtual wedge and the radiation dose distribution and DVH of the treated breast were compared. The beam-on time of each treatment technique was also compared Furthermore, the doses at treated breast skin, contralateral breast skin and skin 1.5 cm away from 4he field margin were also measured using TLD in 7 patients of tangential breast Irradiation and compared the results with phantom measurements. Results: The virtual wedge showed a decreased peripheral dose than those of a typical physical wedge at 15$^{\circ}$, 30$^{\circ}$, 45$^{\circ}$, and 60$^{\circ}$. According to the TLD measurements with 15$^{\circ}$ and 30$^{\circ}$ virtual wedge, the Irradiation dose decreased by 1.35$\%$ and 2.55$\%$ In the contralateral breast and by 0.87$\%$ and 1.9$\%$ In the skin of the contralateral breast respectively. Furthermore, the Irradiation dose decreased by 2.7$\%$ and 6.0$\%$ in the Ipsllateral lung and by 0.96$\%$ and 2.5$\%$ in the heart. The VW fields had lower peripheral doses than those of the PW fields by 1.8$\%$ and 2.33$\%$. However the skin dose Increased by 2.4$\%$ and 4.58$\%$ In the Ipsliateral breast. VW fields, In general, use less monitor units than PW fields and shoriened beam-on time about half of PW. The DVH analysis showed that each delivery technique results In comparable dose distribution in treated breast. Conclusion: A modest dose reduction to the surrounding normal tissue and uniform target homogeneity were observed using the VW technique compare to the PW beam in tangential breast Irradiation The VW field is dosmetrically superlor to the PW beam and can be an efficient method for minimizing acute, late radiation morbidity and reduce 4he linear accelerator loading bV decreasing the radiation delivery time.

• Progress in Medical Physics
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• v.26 no.2
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• pp.93-98
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• 2015

The purpose of this study is to see the usefulness of lead apron for critical organs near the breast under examining. For clinical experiment, 30 female volunteers who agreed to their participation in the experiments, were chosen and divided into two groups, 15 in group A and 15 in group B respectively. group A is to see whether each side of breast under mammography affects to other side glandular on the critical organs is same, because it is not allowed to scan the both breast for same person or to scan repeatedly. Group B is to see the effectiveness of lead apron during the mammography of right breast. Glass dosimeters were placed on the thyroid, the contralateral breast, and lower abdomen where near the breast during examining. The average glandular doses on the surface in mammography of the thyroid gland, the contralateral breast, the lower abdomen were 0.0692 mGy, 0.6790 mGy, and 0.0122 mGy, respectively, which was an extremely low level of glandular dose. In group B, as to the thyroid gland, average dose was decreased from 0.0922 mGy to 0.0158 mGy. The average dose of contralateral breast was decreased from 0.8575 mGy to 0.0286 mGy. The average doses of lower abdomen was decrease 0.0150 mGy to 0.0173 mGy. As to the lower abdomen, dose decreased from 0.0150 mGy before the use of an apron down to 0.0173 mGy after the use. As p-value was under 0.05, statistically significant difference was observed between the two groups. Wearing an apron can have the protective effects on the thyroid gland up to 20 times lower than not wearing one. Besides, it is also necessary to protect the other breast during the examination by wearing one.

• Journal of the Korean Society of Radiology
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• v.8 no.4
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• pp.155-161
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• 2014

Mammography is mostly performed by series projection on both breasts. While taking mammography, it is less than average glandular dose of 3 mGy which regulated. But mammography is exposed much more doses actually, due to additional or series projection. Also, it is difficult to recognize around organ dose except exposed breast. Using mathematical simulation of radiation exposure body in mammography, we studied around organ dose distribution by changing thickness(25, 30, $50{\mu}m$) of filter and relative absorption dose rate which set on basis of exposed breast. as a result, when setting of basis of exposed breast, dose of opposite breast is more affected approximately from 79.26 to 86.31%. when using $25{\mu}m$ of filter thickness than $30{\mu}m$, $50{\mu}m$ of filter thickness in Mo/Mo, W/Rh combination which used actually, absorbed dose rates for opposite breast and around organ were low.

• Journal of radiological science and technology
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• v.35 no.4
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• pp.293-298
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• 2012

In digital mammography, Exposure factor were automatically chosen using by measurement breast thickness and the density of mammary gland. It may cause a increase glandular dose. The purpose of this study was to investigate optimal image quality in digital magnification mammography to decrease radiation exposure of patient dose. Auto mode gives the best image quality however, AGD showed better image quality. Image quality of manual mode passed phantom test and SNR at 55% mAs of auto mode commonly used in the digital magnification mammography. Also it could reduce AGD. According to result, manual mode may reduce the unnecessary radiation exposure in digital magnification mammography.

• The Journal of the Korea Contents Association
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• v.14 no.6
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• pp.247-254
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• 2014

For the purpose of early diagnosis of the breast cancer, the attention on the screening mammography has been increasing-with supply of digital mammography day by day. Image quality is decided by target materials and filter combinations. Optimized selection by a glandular density and a thickness is needed, because these combinations change x-ray spectrum and effect to image quality. The purpose of this study is to find out optimized target and filter combinations through the evaluation of quantitative image quality and to suggest means which minimize patient dose through MCNPX. In results, spatial frequency resolution evaluation which is quantitative image quality evaluation method, MTF, NPS, DQE shows that we have to select Mo/Mo combinations or Mo/Rh combinations when compressed breast is thin. but in case of that when compressed breast is thick, we have to select Rh/Rh combinations or W /Rh combinations. In a comprehensive evaluation, W!Rh combinations which are not used in thin breasts in practice was superior to all image quality evaluation. This result is somewhat different-with clinical examination results. Secondary end point was organ dose evaluation, radiation dose of opposite breast was approximately 47 ~73% effectiveness when selecting standard breast. In conculsion, the most important point is that we have to select the optimal combinations-with considering dose evaluation and various thickness.

• Journal of radiological science and technology
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• v.39 no.4
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• pp.483-491
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• 2016

The conditions after exposure to digital mammography and digital breast tomosynthesis were analyzed. The examinations for the ACR phantom were done using manual exposure, not auto exposure, to examine image discrimination and patient dose. As a result, the following results were derived: In the CC exposure, the kVp was 2kVp higher while mAs decreased to 58.6% for the 3D tomography. Such result showed an approximate decrease of 60mAs. At that time, the patients' Average Glandular Dose (AGD) was 1.65mGy in 2D and 1.87mGy in 3D; thus, AGD of 3D was shown to have about 1.13times higher. The result of the manual exposure revealed a reduced mAs of up to 80%; there was no effect in the assessment standard in terms of image discrimination, resulting in more than 10 points. When mAs was reduced to 80% in the manual exposure for ACR phantom, AGD was decreased to 0.66mGy. The diagnostic values of images were maintained and patients dose was reduced in the manual exposure in the AEC condition for 3D. Since the use of 3D has recently increased, using the manual exposure has been recommended in this study to improve the diagnostic value, while, simultaneously reducing patients dose.

• Journal of radiological science and technology
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• v.29 no.1
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• pp.21-28
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• 2006

I made inquires about mammographic equipments and circumstances of mammography rooms in the 64 medical facilities in areas of Seoul and Kyong Gi Do. Moreover I had experments about exposure dose with patients and radiologic technologists. so there is the data indicated follows. 1. There are inclined to improve in quality and function of mammographic equipments, it has been proven that s/f system exchanged to DR system. 2. It is certain that the number of examinations are becoming increasingly significant. 3. The Space Scattered Dose of mammography rooms are much more larger than portable equipments. 4. I worry about the affection of expose dose about Space Scattered Dose of mammography room. 5. There is need of study how to cope with the situation about increasing exposure dose of radiologic technologists in small space and numeruous number of examinations.