• Journal of radiological science and technology
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• v.28 no.4
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• pp.301-306
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• 2005

Purpose : The goal of this study was to survey the quality control of mammographic phantom images in some area. Methods : Between May and June, 2005, I have got a total of 47 mammographic phantom images collected from 49 hospitals and were analized about phantom score of fibrous, speck, tumor with enlargement scope. By critic level of experimental mammographic phantom case images, classified through the pass case that fibrous score 4, speck score 3, tumor score 3 over. Result : It passed 33case (70.3%), failed 14 case (29.7%) about 47 case. Passing case images showed tube voltage $23{\sim}30\;kVp$, tube current $20{\sim}60\;mAs$, photographic density $0.48{\sim}1.77$ Conclusion : It passed case about 70.3% of mammographic phantom image in some area. Optimum range of tube voltage, tube current, photographic density have to use to get fine quality of mammographic images.

• Journal of radiological science and technology
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• v.45 no.2
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• pp.103-109
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• 2022

To maintain improved image quality in mammography, the quality control process is performed using the ACR (American college of radiology) phantom. In addition, many studied were performed by fabricating the customized breast phantom to provide more information in mammography. Thus, the purpose of this study was to evaluate the image quality by designing the modified ACR phantoms. The five modified acrlylic ACR phantoms were designed by considering insert position and phantom thickness. The phantoms were consisted of 4.5, 3.0, and 1.5 cm in terms of phantom thickness, and 3.0, 2.0, and 0.5 cm in terms of insert position, respectively. The acquired images were evaluated by PSNR (peak signal to noise ratio), RMSE (root mean square error), CC (correlation coefficient), CNR (contrast to noise ratio), and COV (coefficient of variation). Based on the similarity analysis, the result is suitable between conventional and new designed phantoms. In addition, the CNR and COV results in terms of insert position showed that image quality for 0.5 cm was 2.3 and 27.4% improved compared with 2 and 3 cm, respectively. According to phantom thickness results, the CNR result for 1.5 cm and COV result for 4.5 cm were 50.1 and 62.7% improved compared with that those conditions. In conclusion, we confirmed that the image quality depends on the breast size and thickness through modified ACR phantom study.

• Korean Journal of Digital Imaging in Medicine
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• v.12 no.2
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• pp.89-95
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• 2010

High contrast and high resolution are the most important factors for examining mammography images. Despite of the inconveniences of screen-film, most clinics still prefer them to computed radiography(CR) and direct radiography(DR). The reading of screen-film mammography images is influenced by the brightness from the X-ray illuminator, the exam room and incoming light from outside sources. Therefore, a comparative analysis on the results of mammo phantom images would be variated by the changes in the reading environment. There was no influence on reading results from the examiners close distance eyesight(p > 0.05); however, reading of micro lesions improved with greater darkness in the X-ray film reading room and the brightness of the X-ray illuminator(p < 0.05). Also, observation of fiber and mass images were maximized at a distance of 50 cm from the reader. Now, it is possible to observe these small classification groups using a magnifying glass without being physically close to the image. For the image of mammography, obtaining high quality images is important but in order to get an accurate clinical lesions of the reading also needs to be considered the optimal environmental factors.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.415-417
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• 2002

Images of microcalcification specks showed large variation in conventional radiographs of phantoms which are approved for mammography image quality standard by the American College of Radiology (ACR). This kind of variation is not appropriate for image quality standards because the number of specks are visually counted in images and that number is important in image quality evaluation. Our study using synchrotron radiation (SR) imaging revealed the overlapping of micro-sized air bubble(s) to some specks, and also the structural deformation or crackings. Eight phantoms approved by ACR from two different makers and an air-bubble phantom were examined. SR imaging was performed at a synchrotron radiation facility, SPring-8, in Japan. The image-detector was a fluorescent-screen optical-lens coupling system using a CCD camera with a spatial resolution of 6 $\square$m. Objects when imaged with longer sample-to-detector distance show edge enhancement due to a difference in refraction indices, that is refraction enhancement. Refraction-enhanced SR images revealed that some of specks carried foreign objects, which were proven to be air. In phantoms provided by one maker, attaching/overlapping airs were observed for 62 out of 150 specks (41%) , with a higher incidence for the smallest specks. A speck becomes hardly visible in a conventional radiograph when air(s) overlaps the majority part of a speck, though depending on the size of the air-inclusion and on its configuration. Those airs might have been adsorbed on a speck surface before being embedded and then introduced into the matrix together with specks. Our study using SR imaging has clearly shown the nature of defects in some mammography phantoms which seriously degrade the quality as an image standard.

• Journal of Radiation Industry
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• v.12 no.4
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• pp.287-290
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• 2018

Nowadays, diseases related with breast are increasing rapidly and because of this high quality of resolution images is required to get clear detail specially for early detection and diagnosis. It has a tendency to use digital equipments than analog one in clinic. In this experiment, DR, CR, and Film are used for the resolution applied by AEC. Resolution phantom in DR was $7LP{\cdot}mm^{-1}$ in both verticality and horizontality. In CR, however, it was $6LP{\cdot}mm^{-1}$ in both which was lower this standard. The resolution stayed in range of standard in Film but it showed differences between $11{\sim}14LP{\cdot}mm^{-1}$ Overall, the difference of resolution was displayed Film, DR and CR, in order, which means the study is needed for more high quality of digital images.

• Proceedings of the Korean Society of Medical Physics Conference
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• 1999.11a
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• pp.285-286
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• 1999

• Journal of radiological science and technology
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• v.38 no.3
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• pp.221-228
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• 2015

Purpose: In digital mammography QC program was used for the purpose of reducing low-dose and high-definition images of the radiation dose. Materials and Methods: In digital mammography using a QC phantom according to the average glandular dose in the exposure method MLO view $0^{\circ}C$, $30^{\circ}C$, $45^{\circ}C$, $50^{\circ}C$, $55^{\circ}C$, $70^{\circ}C$, was measured at $90^{\circ}C$ intervals, an image with Hologic QC program to the SNR and CNR was measured to evaluate. Results: The average dose in the MLO view was wired to $90^{\circ}C$ when the maximum was 1.75 mGy, it decreased approximately 6% was measured at $45^{\circ}C$ 1.65 mGy. In addition, 1.67 mGy, manual record, there were an average wired in accordance with the exposure dose and the dose of 1.52 mGy difference in the way auto filter. Image quality evaluation at every angular section SNR 50 ~ 52, shows a slight difference in CNR 11 ~ 12, it was included in the manufacturer's recommended value. Conclusion: The dose was lowest in MLO view $45^{\circ}C$, the difference between SNR and CNR were insignificant. The method of exposure will need a way to reduce the exposure of the patient's body or unnecessary patient by placing a difference in settings in which the characteristics.

• Journal of radiological science and technology
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• v.40 no.3
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• pp.443-451
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• 2017

Mammography is commonly used for screening early breast cancer. However, mammographic images, which depend on the physical properties of breast components, are limited to provide information about whether a lesion is malignant or benign. Although a dual-energy subtraction technique decomposes a certain material from a mixture, it increases radiation dose and degrades the accuracy of material decomposition. In this study, we simulated a breast phantom using attenuation characteristics, and we proposed a technique to enable the accurate material decomposition by applying weighting factors for the dual-energy mammography based on a photon-counting detector using a Monte Carlo simulation tool. We also evaluated the contrast and noise of simulated breast images for validating the proposed technique. As a result, the contrast for a malignant tumor in the dual-energy weighted subtraction technique was 0.98 and 1.06 times similar than those in the general mammography and dual-energy subtraction techniques, respectively. However the contrast between malignant and benign tumors dramatically increased 13.54 times due to the low contrast of a benign tumor. Therefore, the proposed technique can increase the material decomposition accuracy for malignant tumor and improve the diagnostic accuracy of mammography.

• Progress in Medical Physics
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• v.23 no.4
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• pp.261-268
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• 2012

Breast cancer is the second leading cause of women cancer death in Korea. The key for reducing disease mortality is early detection. Although digital mammography (DM) has been credited as one of the major reasons for the early detection to decrease in breast cancer mortality observed in the last 20 years, DM is far from perfect for several limitations. Digital breast tomosynthesis (DBT) is expected to overcome some inherent limitations of conventional mammography caused by overlapping of normal tissue and pathological tissue during the standard 2D projections for the improved lesion margin visibility and early breast cancer detection. In this study, we compared a DM system and DBT system acquired with different thickness of breast phantom. We acquired breast phantom data with same average glandular dose (AGD) from 1 mGy to 4 mGy under same experimental condition. The contrast, micro-calcification measurement accuracy and observer study were conducted with breast phantom images. As a result, the higher accuracy of lesion detection with DBT system compared to DM system was demonstrated in this study. Furthermore, the pain of patients caused by severe compression can be reduced with DBT system. In conclusion, the results indicated that DBT system play an important role in breast cancer detection.

• Journal of radiological science and technology
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• v.38 no.3
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• pp.229-235
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• 2015

Mammoplasty is currently increasing not only for cosmetic surgery, but as well as for the recovery after breast cancer surgery. The prostheses inserted into the breasts of women who have undergone mammoplasty, hide the breast substances and it is becoming increasingly difficult to diagnose breast disease, and fear is growing by the concern of the prostheses bursting by the strap. So we want to develop a strap applicable to women with prostheses inserted, to determine the usefulness, and we also want to compare the utility by comparing the total area of the Inner and Outer parts of the breast and Posterior Nipple Line (PNL), after obtaining video by applying the existing strap and the developed strap to phantom of the prostheses inserted patient shape. When the pressure by the developed pressure, the total area increased by 10.09% from CC view to $9,813.797mm^2$, 3.88% from CC-ID view to $7,621.531mm^2$, PNL increased by 3.41% from CC view to $90.916mm^2$, 1.64% from CC-ID view to$75.357mm^2$. And the breast tissue of the thorax side increased 3.53% from CC view to $177.725mm^2$, and 6.57% from CC-ID view to $152.510mm^2$, and we could verify that the prostheses were completely eliminated in the CC-ID images of developed strap, compared with the existing strap.