• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.319-321
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• 2004

The average glandular dose (AGD) is determined by the breast entrance skin exposure, x-ray tube target material, beam quality (half-value layer), breast thickness, and breast composition. Almost breast cancer always arises in glandular breast tissue. As a result, the average radiation absorbed dose to glandular tissue is the preferred measure of the radiation risk associated with mammography. If the normalized average glandular dose is known, the average glandular dose can be computed from the product of the normalized average glandular dose and breast entrance skin exposure. In this study, AGD was calculated by the breast thickness and various x-ray energy (HVL) in 50% glandular 50% adipose breast by Mo.-Rh. assembly. AGD is 84 mrad in compressed 5 cm breast. These results show that as increasing the breast thickness, dose also increases. But as increasing the x-ray tube voltage, dose decreases because of high penetrating ratio through the object. But high tube voltage is reducing the subject contrast. From this result, we have to consider the trade-off between subject contrast of image and dose to the patient and choose proper x-ray energy range.

• Journal of radiological science and technology
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• v.37 no.2
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• pp.101-107
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• 2014

The purpose of this study was investigated optimal exposure condition in digital magnification mammography to decrease radiation dose and increase image quality of the examinee. Auto mode, the average glandular dose is higher than the manual mode. Average glandular dose and image quality were many differences on between grid and air gap technique in auto mode. However, Average glandular dose and signal-to-noise ratio were not different on between grid and air gap technique in manual mode. The signal-to-noise ratio was increased when using the air-gap technique in both mode. According to result, air gap technique may reduce average glandular dose and increase signal-to-noise ratio in digital magnification mammography.

• Journal of the Korean Society of Radiology
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• v.5 no.3
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• pp.111-120
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• 2011

A purpose of study is to develop optimization and radiation dose exposure reference level by measuring actual radiation dose in condition of quality control of mammography equipment for 39 clinics. The result were as follows. First, we measured T-test separating radiology from general clinic. According to the test, mAs was measured at average 78.58 mAs; radiology at 80.16 mAs and general clinic at 77.22 mAs. And, kerma rate was measured at average 7.71 mGy/mR; radiology at 8.94 mGy/mR and general clinic at 6.66 mGy/mR. HVL was measured at average 0.42 mmAl; radiology at 0.40 mmAl and general clinic at 0.43 mmAl. Average glandular dose was measured at average 1.14 mGy; radiology at 1.09 mGy and general clinic at 1.19 mGy. Second, we measured value of mAs, HVL, processing method and so on dividing two groups. And, we compared and analyzed average value measured using T-test. As a result, there was significance level in SID(P<0.05). There was significance level in mAs(P<0.05). Because processor was measured at 1.00 mGy and CR at 1.17 mGy according to the processing method of radiology. Third, according to the correlation analysis, radiology had significance level between average glandular dose and mAs and general clinic had significance level between average glandular dose and SID(P<0.05). Forth, as a result of regression analysis, mAs affected 22.7%t of average glandular dose and SID affected 21.7% of average glandular dose, which had significance level(P<0.05). And, mAs affected 29.0% of average glandular dose in radiology and SID affected 29.1% of average glandular dose in general clinic, which was most influential.

• 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.

• Korean Journal of Digital Imaging in Medicine
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• v.12 no.2
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• pp.133-138
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• 2010

The purpose of this study was to survey and test quality control of mammography system. The conclusion of this study is as follows ; First, The rate of pass for phantom image test shows that Film-Screen mammography system(F/S) and computed mammography system(CR) is 80%, Indirect digital mammography system(DR) is 100%. Second, The test of exposure dose shows that F/S is 921 mR. CR is 1,140 mR, DR is 474 mR. The grade of this testament is CR > F/S > DR. Third, The test of average glandular dose shows that F/S is 1,336 mGy, CR is 1,635 mGy, DR is 1,26 mGy. The grade of this testament is CR > F/S > DR. Fourth, The testament of resolution shows as follows F/S is 11~13 Lp/mm, CR is 4~5 Lp/mm, and DR is 5~7 Lp/mm(F/S > DR > CR) Fifth, The survey of projection, cassette, development and reading shows that user are indifference.

• Korean Journal of Digital Imaging in Medicine
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• v.15 no.2
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• pp.19-23
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• 2013

Purpose : Automatic exposure system(AOP mode) in DR Mammography of the STD and DOSE apply to women of childbearing age, the average glandular dose(AGD) and image quality by comparing was to demonstrate the usefulness of DOSE. Materials and Methods : Of the under 40 age 108 patients who visit to our hospital and examined STD and DOSE mammography from January 2008 to July 2013. AGD was obtained by DICOM header information provided by GE Senographe DS. STD and DOSE images were evaluated with obtained patients, Image J program was compared by calculating the SNR. Results : The average AGD of DOSE mode was 0.99mGy, and which decreased by 19% comparing to that of STD mode which was 1.18mGy. The two the average AGDs indicated statistically significant difference(p< .01). The average SNR of STD was 40.26, DOSE displayed, and to 39.68 in, there was no statistical significance. Results : The average AGD using DOSE mode which is one of DR mammography AOP modes decreased by comparing to that of STD mode showing no difference in image quality. The use of DOSE is considered to be useful.

• Korean Journal of Digital Imaging in Medicine
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• v.12 no.1
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• pp.33-41
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• 2010

National Cancer Screening Project and Korean Society of Breast Imaging recommend that breast cancer screening should be performed on those aged 40 and above. Nevertheless, this recommendation is usually ignored by a number of medical institutions. The purpose of this study is to emphasize the necessity of an age limitation in screening mammography. Ten institutions were randomly selected and telephone inquiries about patients' age limitation and internal guidelines were set up. The 3,214 women, who underwent screening mammography through 'GE Senography 2000D' in each hospital, were classified into five groups according to age(from 20s to 40s, at intervals of 5). And then, collected data was analyzed by a radiologist in accordance with ACR-BIRADS(American College of Radiology Breast Imaging Reporting and Data System), through which breast parenchymal density and the results of analysis were categorized in order to predict the sensitivity of mammography. Information about craniocaudal-view mammograms was automatically produced by use of GE Senography 2000D, and the average glandular dose was retrospectively analyzed through the program 'Excel 2007.' Two institutions did not set the age limitation. Other seven institutions internally allowed those who wanted to receive mammography regardless of age. Approximately 99% of those aged 20 to 29 were judged as having the dense breast. In those aged 35 to 39, breast parenchymal density tended to be lower, but the fatty breast to increase. In the case of 'category-zero' that does not need additional tests, the rate of 'heterogeneously dense' and 'extremely dense' reached to 83.1% and 15.1% respectively. Regarding dense breasts, there was no sufficient information for image reading. The glandular dose, applied to 3,214, was 1.47mGy on the average. In those aged 20 to 24 who are sensitive to radiation, the average glandular dose indicated 1.59mGy. Those aged 35 and above showed the lowest value, 1.43mGy. In those aged 35 to 39, the breast tended to change from denseness to fattiness. The average glandular dose was lowest in those aged 35 and above, which suggests that screening mammography should be periodically performed on those aged 35 and above in order that breast cancer may be early detected. On the other hand, in those aged less than 35, it is difficult to analyze mammograms due to the high density of breast parenchyma, and also retakes become frequent. In particular, subjects may be exposed to excessive doses. Accordingly, it should be substituted by breast self-examination or clinical breast examination. In case of need, it is advisable to perform ultrasonography.

• Journal of radiological science and technology
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• v.25 no.2
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• pp.47-55
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• 2002

We came to the following conclusion as the results of experiment on the image quality of mammography and the average glandular dose using 4 apparatuses at 3 hospitals in Seoul. 1. Whereas the measurement of half value layer showed no differences among the apparatuses, the measurement by an attenuation curve method showed some differences by 5.9%. There were 9.1% differences in the measurement by aluminum conversion method. 2. The basic density of an automatic exposure control unit must be D = 1.40, but there was no automatic exposure unit adjusted precisely at any hospitals. The unit at the B hospital exceeded the allowable limit by ${\pm}0.15$. 3. In the photographing using an automatic exposure control unit and the management of an automatic film processor using a sensitometer, most automatic film processors were well kept. But in some cases the mean value of a fluctuation coefficient exceeded the allowable limit. There is a need for more cautious management. 4. The image quality of breast phantom photography was affected by the screen/film system among the hospitals. 5. The average glandular dose at a breast of 4.2 cm thickness depended on the tube voltage, In the case of Mo/Mo, it was measured $0.26{\sim}1.39\;mGy$ less than ACR standard 3.0 mGy.

• Journal of the Korean Society of Radiology
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• v.16 no.3
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• pp.303-308
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• 2022

Mammography using X-rays is currently the most used for early diagnosis of breast cancer. As the frequency of use of X-ray devices increases, interest in radiation hazards caused by mammography is increasing. Therefore, in this study, in order to measure the exposure dose of the mammary gland in X-ray mammography that requires high contrast and high resolution, the international Atomic Energy Agency (IAEA) stipulates the international standards presented by IEC 62220-1-2: 2015. Based on the beam quality criteria of the recommendation, we tried to present a guideline for evaluating the average mammary gland dose. As a result, the average streamline dose value of the 4.5 cm PMMA phantom was 2.3 mGy at the maximum within the 30 kV range, and was evaluated to be 1.19 mGy based on 28 kV.

• 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.