[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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Mammography systems equipped with the Mo target (A) and W target (B) used at our clinic have different characteristics in terms of the image quality obtained and the beam quality. We con-sidered the following to establish indices for examining patients under follow-up, focusing on the ability for visualization of the abnormalities and the average glandular dose (AGD). We in-cluded 175 patients in whom the procedure was conducted with B recently or with A in January 2018. We investigated 1) the ability to visualize the findings, and 2) the AGD. We investigated using display values in AGD. 1-1) The findings in the 26 cases with masses were as follows: A < B, 9cases; A=B, 14cases; A > B, 3cases. 1-2)The findings in the 34 cases with small round calcifications were as follows: A > B, 0case; A=B, 29cases; A < B, 5cases. The findings in the 18 cases with amorphous calcifications were as follows: A > B, 7cases; A=B, 11cases; A < B, 0case. Based on the findings, we concluded that it is better to use A for all cases with calcifications, considering the clinical importance of amorphous calcification. 1-3) The findings in 15 cases with FAD were as follows: A > B, 5cases; A=B, 6cases; A < B, 4cases. Thus, no significant differences between the two devices were found for cases of FAD. 2) In regard to the difference depending on the breast thickness, it was A > B in cases with a breast thickness of 50mm, but B > A in cases with a breast thickness of  55mm. This trend was seen in all the mammary gland ratio . In conclusion, considering the previous findings, it would be de-sirable to select B for cases with masses and A for cases with calcifications. Furthermore, con-sidering the need for use of the minimal radiation dose, B should be selected for cases with a breast thickness of 50mm and A for cases with a breast thickness of 55mm.

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Both the number of breast cancer cases and the number of deaths from breast cancer are increasing in Japan. It was estimated in 2013, that one in 11 Japanese women suffers from breast cancer in her lifetime. In 2018, breast cancer was reported as the most common cancer among Japanese women, and the number of patients was estimated to be 86,500. After the guidelines for cancer prevention focused on health education and cancer screening were partially revised, inspection/palpation for breast cancer screening was virtually abolished. We conducted an internet survey to determine the implementation system of breast cancer screening after the guideline revision and prior research in Gunma prefecture. The survey period was from February 2, 2018 to March 31, 2018. Of the 35 municipalities of Gunma prefecture surveyed, 21 municipalities (60.0%) disclosed information about their mass screening program for breast cancer and 12 (34.3%) disclosed information about individual screening. Information on medical checkup sent on the Internet was not the most common method, and notification of individuals through paper media, such as medical checkup information by post and public relations magazines, was more frequently used. In Gunma prefecture, 27.6% of all the cities, towns and villages carries out mammography alone for mass screening and 35.3% carried it out for individual screening. It is reported that women’s disgust at breast palpation and being inhibited by male doctors’ involvement in screening were among the screening inhibiting factors. We suggest that as the main method of examination has shifted from palpation to mammography alone, the screening rate could improve. In addition, a negative correlation was found in the rate of mass screening and the amount of copay in each municipality in Gunma Prefecture, and it was inferred that the amount of co-pay influenced the examination behavior.

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During stereotactic vacuum―assisted breast biopsy (ST―VAB), a marker is placed at the site of microcalcifications in order to indicate the target position. However, there are cases where the marker placed during the biopsy moves from the target position. Therefore, we defined the posterior nipple line (PNL) as the reference line on mammographic images and examined the evaluation method and factors involved in marker movement. From August 2016 to August 2018, markers were placed during ST―VAB, followed by mammography (MMG) in 41 women was taken. Among the 41 cases, marker migration by less than 20 mm was observed in 80% cases, by less than 20―30 mm in 5% cases, and by 30 mm or more in 15% cases. In the evaluation of the influence of the insertion direction, marker movements were more frequently observed in the lateromedial oblique projection (LMO), lateromedial projection (LM), inferomedial to superolateral oblique projection (ISO), with a tendency for the marker to move forward in the insertion direction. Markers showing a large degree of migration were pushed out from the tip of the opening and migrated in front, and then moved further due to the accordion effect after relieving the pressure. There was a significant difference in the degree of marker movement between the insertion direction ISO and other insertion directions. This is thought to be mainly attributable to the accordion effect and the rolling effect, wherein the mammary gland is rotated to bring out the chest wall during positioning. Evaluation using the PNL as reference suggested that the marker movement is influenced by the insertion direction.

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Purpose: The purpose of this study was to investigate the volumetric breast density and conduct diagnostic evaluation of women with abnormal screening mammography. Patients and Methods: The study included 108 women with abnormal findings on screening mammography who were examined at our institution from February 2019 to July 2019. The volumetric breast density using VolparaTM and the compressed breast thickness (CBT) were measured in a total of 108 patients. The clinical features and CBT were compared using the chisquare test between women with density a or b (Non-dense group) and those with density c or d (Dense group) using chi-square tests. Results: The median age of the patients was 51.5 years, and the median CBT was 41 mm. Of the 108 women, 16 (15%) were classified into the Non-dense group and the remaining 92 (85%) into the Dense group. The median age of the women in the Dense group was 48.5 years, and there were more women under the age of 50 years. All the patients with CBT < 30 mm were classified into the Dense group. There was no significant difference in the percentage of cases in diagnostic mammography category 3-5 or the malignancy rate between the two groups. Conclusions: Among women with abnormal screening mammography, 85% were assessed as having dense breasts. Our study showed age < 50 years and/or CBT < 30 mm were frequently associated with dense breasts, and this remains a challenge to address.

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