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Sample records for regular two-view mammography

  1. Second-screening mammography: One versus two views per breast

    International Nuclear Information System (INIS)

    Ikeda, D.M.; Sickles, E.A.

    1987-01-01

    To compare the advantages of single-versus two-view follow-up screening mammograms, oblique and craniocaudal examinations from 1,000 asymptomatic women who had prior normal baseline studies were reviewed retrospectively, first using only the oblique projection, then using the oblique and craniocaudal views. Single-view readings of dense breasts resulted in considerably more abnormal interpretations then were made with two-view readings. The induced costs from these false-positive readings more than offset the small savings in operating expense of single-view reading. In contradistinction, so few false-positive readings were made in women with fatty breasts (in whom superimposition of dense tissue is not a problem) that savings in operating expense exceeded induced costs

  2. Reduction in interval cancer rates following the introduction of two-view mammography in the UK breast screening programme

    Science.gov (United States)

    Dibden, A; Offman, J; Parmar, D; Jenkins, J; Slater, J; Binysh, K; McSorley, J; Scorfield, S; Cumming, P; Liao, X-H; Ryan, M; Harker, D; Stevens, G; Rogers, N; Blanks, R; Sellars, S; Patnick, J; Duffy, S W

    2014-01-01

    Background: The introduction of two-view mammography at incident (subsequent) screens in the National Health Service Breast Screening Programme (NHSBSP) has led to an increased number of cancers detected at screen. However, the effect of two-view mammography on interval cancer rates has yet to be assessed. Methods: Routine screening and interval cancer data were collated from all screening programmes in the United Kingdom for women aged 50–64, screened between 1 April 2003 and 31 March 2005. Interval cancer rates were compared based on whether two-view mammography was in use at the last routine screen. Results: The reduction in interval cancers following screening using two-view mammography compared with one view was 0.68 per 1 000 women screened. Overall, this suggests the introduction of two-view mammography at incident screen was accompanied by a 15–20% reduction in interval cancer rates in the NHSBSP. Conclusion: The introduction of two-view mammography at incident screens is associated with a reduction in incidence of interval cancers. This is consistent with previous publications on a contemporaneous increase in screen-detected cancers. The results provide further evidence of the benefit of the use of two-view mammography at incident screens. PMID:24366303

  3. Diagnostic accuracy and recall rates for digital mammography and digital mammography combined with one-view and two-view tomosynthesis: results of an enriched reader study.

    Science.gov (United States)

    Rafferty, Elizabeth A; Park, Jeong Mi; Philpotts, Liane E; Poplack, Steven P; Sumkin, Jules H; Halpern, Elkan F; Niklason, Loren T

    2014-02-01

    The purpose of this study was to compare two methods of combining tomosynthesis with digital mammography by assessing diagnostic accuracy and recall rates for digital mammography alone and digital mammography combined with one-view tomosynthesis and two-view tomosynthesis. Three hundred ten cases including biopsy-proven malignancies (51), biopsy-proven benign findings (47), recalled screening cases (138), and negative screening cases (74) were reviewed by 15 radiologists sequentially using digital mammography, adding one-view tomosynthesis, and then two-view tomosynthesis. Cases were assessed for recall and assigned a BI-RADS score and probability of malignancy for each imaging method. Diagnostic accuracy was assessed using receiver operating characteristic (ROC) analysis. Screening recall rates were compared using pooled logistical regression analysis. A p value of tomosynthesis, and DM plus two-view tomosynthesis was 0.828, 0.864, and 0.895, respectively. Both one-view and two-view tomosynthesis plus DM were significantly better than DM alone (Δ AUCs 0.036 [p = 0.009] and 0.068 [p tomosynthesis, and DM plus two-view tomosynthesis were 44.2%, 27.2%, and 24.0%, respectively. Combined with DM, one-view and two-view tomosynthesis both showed significantly lower noncancer recall rates than digital mammography alone (p tomosynthesis showed a significantly lower recall rate than digital mammography with one-view tomosynthesis (p tomosynthesis compared with digital mammography alone. Compared with digital mammography, diagnostic sensitivity for invasive cancers increased with the addition of both one-view (Δ12.0%, p tomosynthesis. The addition of one-view tomosynthesis to conventional digital mammography improved diagnostic accuracy and reduced the recall rate; however, the addition of two-view tomosynthesis provided twice the performance gain in diagnostic accuracy while further reducing the recall rate.

  4. Combination of one-view digital breast tomosynthesis with one-view digital mammography versus standard two-view digital mammography: per lesion analysis

    Energy Technology Data Exchange (ETDEWEB)

    Gennaro, Gisella; Bezzon, Elisabetta; Pescarini, Luigi; Polico, Ilaria; Proietti, Alessandro; Baldan, Enrica; Pomerri, Fabio; Muzzio, Pier Carlo [Veneto Institute of Oncology (IRCCS), Padua (Italy); Hendrick, R.E. [University of Colorado-Denver, Department of Radiology, School of Medicine, Aurora, CO (United States); Toledano, Alicia [Biostatistics Consulting, LLC, Kensington, MD (United States); Paquelet, Jean R. [Advanced Medical Imaging Consultants, Fort Collins, CO (United States); Breast Imaging, McKee Medical Center, Loveland, CO (United States); Chersevani, Roberta [Private Medical Practice, Gorizia (Italy); Di Maggio, Cosimo [Private Medical Practice, Padua (Italy); La Grassa, Manuela [Department of Radiology, Oncological Reference Center (IRCCS), Aviano (Italy)

    2013-08-15

    To evaluate the clinical value of combining one-view mammography (cranio-caudal, CC) with the complementary view tomosynthesis (mediolateral-oblique, MLO) in comparison to standard two-view mammography (MX) in terms of both lesion detection and characterization. A free-response receiver operating characteristic (FROC) experiment was conducted independently by six breast radiologists, obtaining data from 463 breasts of 250 patients. Differences in mean lesion detection fraction (LDF) and mean lesion characterization fraction (LCF) were analysed by analysis of variance (ANOVA) to compare clinical performance of the combination of techniques to standard two-view digital mammography. The 463 cases (breasts) reviewed included 258 with one to three lesions each, and 205 with no lesions. The 258 cases with lesions included 77 cancers in 68 breasts and 271 benign lesions to give a total of 348 proven lesions. The combination, DBT{sub (MLO)}+MX{sub (CC)}, was superior to MX (CC+MLO) in both lesion detection (LDF) and lesion characterization (LCF) overall and for benign lesions. DBT{sub (MLO)}+MX{sub (CC)} was non-inferior to two-view MX for malignant lesions. This study shows that readers' capabilities in detecting and characterizing breast lesions are improved by combining single-view digital breast tomosynthesis and single-view mammography compared to two-view digital mammography. (orig.)

  5. An investigation into why two-view mammography is better than one-view in breast cancer screening

    International Nuclear Information System (INIS)

    Hackshaw, A.K.; Wald, N.J.; Michell, M.J.; Field, S.; Wilson, A.R.M.

    2000-01-01

    AIM: To determine why two-view mammography in screening for breast cancer is more effective than using a single medio-lateral oblique view. MATERIALS AND METHODS: In the United Kingdom Coordinating Committee on Cancer Research randomized trial of one- vs two-view mammography in breast cancer screening the oblique view was assessed by one radiologist and two views (oblique and cranio-caudal) assessed by another. For the present study the mammographic films were retrieved from the screening centres and assessed by three consultant radiologists. Mammographic films were available from 110 women; 87 had their breast cancer detected by both one and two views and in 23 it was missed by one view but detected using two views. Outcome measures were breast size, location and size of the cancer, mammographic features, presence of microcalcification and overall radiological assessment. RESULTS: Although 23 cancers were missed in the original trial when one view was used, only two were not visible on the oblique view. Cancers missed using a single oblique view (and only detected if the cranio-caudal view was available with the oblique) tended to be smaller by about 4 mm (P = 0.05), centrally located in the breast (P = 0.16), not spiculated or round, (P ≤ 0.001) and lacked microcalcification (P = 0.15). Breast size and breast radiographic density were not significantly associated with breast cancer detection. CONCLUSIONS: The results provide the basis for the observation that two-view mammographic screening is more effective than one-view mammographic screening. Hackshaw, A. (2000). Clinical Radiology 55, 454-458

  6. Does gender discrimination impact regular mammography screening? Findings from the race differences in screening mammography study.

    Science.gov (United States)

    Dailey, Amy B; Kasl, Stanislav V; Jones, Beth A

    2008-03-01

    ABSTRACT Objective: To determine if gender discrimination, conceptualized as a negative life stressor, is a deterrent to adherence to mammography screening guidelines. African American and white women (1451) aged 40-79 years who obtained an index screening mammogram at one of five urban hospitals in Connecticut between October 1996 and January 1998 were enrolled in this study. This logistic regression analysis includes the 1229 women who completed telephone interviews at baseline and follow-up (average 29.4 months later) and for whom the study outcome, nonadherence to age-specific mammography screening guidelines, was determined. Gender discrimination was measured as lifetime experience in seven possible situations. Gender discrimination, reported by nearly 38% of the study population, was significantly associated with nonadherence to mammography guidelines in women with annual family incomes of > or =$50,000 (OR 1.99, 95% CI 1.33, 2.98) and did not differ across racial/ethnic group. Our findings suggest that gender discrimination can adversely influence regular mammography screening in some women. With nearly half of women nonadherent to screening mammography guidelines in this study and with decreasing mammography rates nationwide, it is important to address the complexity of nonadherence across subgroups of women. Life stressors, such as experiences of gender discrimination, may have considerable consequences, potentially influencing health prevention prioritization in women.

  7. Replacing single-view mediolateral oblique (MLO) digital mammography (DM) with synthesized mammography (SM) with digital breast tomosynthesis (DBT) images: Comparison of the diagnostic performance and radiation dose with two-view DM with or without MLO-DBT

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hyo-Jin [Department of Radiology, Seoul National University Hospital, 03080 (Korea, Republic of); Chang, Jung Min, E-mail: imchangjm@gmail.com [Department of Radiology, Seoul National University Hospital, 03080 (Korea, Republic of); Department of Radiology, Seoul National University College of Medicine, 03080 (Korea, Republic of); Lee, Joongyub [Medical Research Collaborating Center, Biomedical Research Institution, Seoul National University Hospital, 03080 (Korea, Republic of); Song, Sung Eun; Shin, Sung Ui [Department of Radiology, Seoul National University Hospital, 03080 (Korea, Republic of); Kim, Won Hwa [Department of Radiology, Kyungpook National University Hospital, 41944 (Korea, Republic of); Bae, Min Sun [Department of Radiology, Seoul National University Hospital, 03080 (Korea, Republic of); Moon, Woo Kyung [Department of Radiology, Seoul National University Hospital, 03080 (Korea, Republic of); Department of Radiology, Seoul National University College of Medicine, 03080 (Korea, Republic of); Institute of Radiation Medicine, Seoul National University College Medical Research Center, 03080 (Korea, Republic of)

    2016-11-15

    Objectives: To evaluate the diagnostic performance and radiation dose of single view cranio-caudal (CC) digital mammography (DM) plus mediolateral oblique (MLO) digital breast tomosynthesis (DBT) combined with synthesized mammography (SM) in comparison with two-view DM with or without DBT. Material and methods: This study was approved by our institutional review board, and informed consent was obtained from 130 women. Paired two-view DM and single MLO-DBT with SM images were acquired, and four independent retrospective reading sessions of different combinations of DM, SM and DBT were performed for the presence of malignant tumors using jackknife alternative free-response receiver operator curve (JAFROC) methods. The diagnostic performances and average glandular dose (AGD) were compared between different combinations of DM, SM and DBT. Results: Of 159 lesions in 130 patients, 27 were malignant. When using MLO-DBT with SM instead of MLO-DM, a significantly higher sensitivity (P = 0.016) and specificity (P = 0.012) were noted than with two-view DM, and comparable figure of merit (FOM), sensitivity, and specificity to two-view DM with DBT were noted. The mean AGD of CC-DM plus MLO-DBT with SM was 5.78mGy ± 1.06 per patient, which was significantly lower than that with two-view DM with MLO-DBT (8.45mGy ± 1.32; P <0.001) and slightly higher than that with two-view DM (5.30mGy ± 0.63). Conclusions: The combined use of CC-DM plus MLO-DBT with SM showed higher sensitivity and specificity to two-view DM with a smaller AGD increment and comparable diagnostic performance to that of two-view DM with MLO-DBT with a significantly lower mean AGD.

  8. Comparative evaluation of average glandular dose and breast cancer detection between single-view digital breast tomosynthesis (DBT) plus single-view digital mammography (DM) and two-view DM: correlation with breast thickness and density

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Sung Ui; Chang, Jung Min; Bae, Min Sun; Lee, Su Hyun; Cho, Nariya; Seo, Mirinae; Kim, Won Hwa; Moon, Woo Kyung [Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of)

    2015-01-15

    To compare the average glandular dose (AGD) and diagnostic performance of mediolateral oblique (MLO) digital breast tomosynthesis (DBT) plus cranio-caudal (CC) digital mammography (DM) with two-view DM, and to evaluate the correlation of AGD with breast thickness and density. MLO and CC DM and DBT images of both breasts were obtained in 149 subjects. AGDs of DBT and DM per exposure were recorded, and their correlation with breast thickness and density were evaluated. Paired data of MLO DBT plus CC DM and two-view DM were reviewed for presence of malignancy in a jack-knife alternative free-response ROC (JAFROC) method. The AGDs of both DBT and DM, and differences in AGD between DBT and DM (ΔAGD), were correlated with breast thickness and density. The average JAFROC figure of merit (FOM) was significantly higher on the combined technique than two-view DM (P = 0.005). In dense breasts, the FOM and sensitivity of the combined technique was higher than that of two-view DM (P = 0.003) with small ΔAGD. MLO DBT plus CC DM provided higher diagnostic performance than two-view DM in dense breasts with a small increase in AGD. (orig.)

  9. Comparative evaluation of average glandular dose and breast cancer detection between single-view digital breast tomosynthesis (DBT) plus single-view digital mammography (DM) and two-view DM: correlation with breast thickness and density

    International Nuclear Information System (INIS)

    Shin, Sung Ui; Chang, Jung Min; Bae, Min Sun; Lee, Su Hyun; Cho, Nariya; Seo, Mirinae; Kim, Won Hwa; Moon, Woo Kyung

    2015-01-01

    To compare the average glandular dose (AGD) and diagnostic performance of mediolateral oblique (MLO) digital breast tomosynthesis (DBT) plus cranio-caudal (CC) digital mammography (DM) with two-view DM, and to evaluate the correlation of AGD with breast thickness and density. MLO and CC DM and DBT images of both breasts were obtained in 149 subjects. AGDs of DBT and DM per exposure were recorded, and their correlation with breast thickness and density were evaluated. Paired data of MLO DBT plus CC DM and two-view DM were reviewed for presence of malignancy in a jack-knife alternative free-response ROC (JAFROC) method. The AGDs of both DBT and DM, and differences in AGD between DBT and DM (ΔAGD), were correlated with breast thickness and density. The average JAFROC figure of merit (FOM) was significantly higher on the combined technique than two-view DM (P = 0.005). In dense breasts, the FOM and sensitivity of the combined technique was higher than that of two-view DM (P = 0.003) with small ΔAGD. MLO DBT plus CC DM provided higher diagnostic performance than two-view DM in dense breasts with a small increase in AGD. (orig.)

  10. Mammography

    Science.gov (United States)

    ... breast cancer Whether there is any harm from breast cancer screening, such as side effects from testing or overtreatment of cancer when it's discovered Mammography is performed to screen women to detect early breast cancer when it is ...

  11. Effects of attitude, social influence, and self-efficacy model factors on regular mammography performance in life-transition aged women in Korea.

    Science.gov (United States)

    Lee, Chang Hyun; Kim, Young Im

    2015-01-01

    This study analyzed predictors of regular mammography performance in Korea. In addition, we determined factors affecting regular mammography performance in life-transition aged women by applying an attitude, social influence, and self-efficacy (ASE) model. Data were collected from women aged over 40 years residing in province J in Korea. The 178 enrolled subjects provided informed voluntary consent prior to completing a structural questionnaire. The overall regular mammography performance rate of the subjects was 41.6%. Older age, city residency, high income and part-time job were associated with a high regular mammography performance. Among women who had undergone more breast self-examinations (BSE) or more doctors' physical examinations (PE), there were higher regular mammography performance rates. All three ASE model factors were significantly associated with regular mammography performance. Women with a high level of positive ASE values had a significantly high regular mammography performance rate. Within the ASE model, self-efficacy and social influence were particularly important. Logistic regression analysis explained 34.7% of regular mammography performance and PE experience (β=4.645, p=.003), part- time job (β=4.010, p=.050), self-efficacy (β=1.820, p=.026) and social influence (β=1.509, p=.038) were significant factors. Promotional strategies that could improve self-efficacy, reinforce social influence and reduce geographical, time and financial barriers are needed to increase the regular mammography performance rate in life-transition aged.

  12. Mammography

    International Nuclear Information System (INIS)

    1975-01-01

    This patent reveals a method and instrument for the detection and registration of breast cancer with the aid of X-radiation, i.e. mammography. The breast is irradiated with soft X-rays whereby the radiation beam is scanned with a moving 'stripform' screen and whereby the picture from the 'stripform' screen is recorded by a television camera that moves simultaneously with the strip. The image is then projected on a monitor

  13. Can missed breast cancer be recognized by regular peer auditing on screening mammography?

    Science.gov (United States)

    Pan, Huay-Ben; Yang, Tsung-Lung; Hsu, Giu-Cheng; Chiang, Chia-Ling; Huang, Jer-Shyung; Chou, Chen-Pin; Wang, Yen-Chi; Liang, Huei-Lung; Lee, San-Kan; Chou, Yi-Hong; Wong, Kam-Fai

    2012-09-01

    This study was conducted to investigate whether detectable missed breast cancers could be distinguished from truly false negative images in a mammographic screening by a regular peer auditing. Between 2004 and 2007, a total of 311,193 free nationwide biennial mammographic screenings were performed for 50- to 69-year-old women in Taiwan. Retrospectively comparing the records in Taiwan's Cancer registry, 1283 cancers were detected (4.1 per 1000). Of the total, 176 (0.6 per 1000) initial mammographic negative assessments were reported to have cancers (128 traditional films and 48 laser-printed digital images). We selected 186 true negative films (138 traditional films and 48 laser-printed ones) as control group. These were seeded into 4815 films of 2008 images to be audited in 2009. Thirty-four auditors interpreted all the films in a single-blind, randomized, pair-control study. The performance of 34 auditors was analyzed by chi-square test. A p value of auditing should reduce the probability of missed cancers. 2012 Published by Elsevier B.V

  14. Communications and Development: Two Views.

    Science.gov (United States)

    Development Communication Report, 1977

    1977-01-01

    Two views on current international communication are presented--that of an American academician, and that of an Indian journalist. John Lent traces the rise of development journalism and development communication from the point of view of those who believe that individual freedom of expression should be treated as an inviolable right. Narinder…

  15. Mammography and radiation risk; Mammographie und Strahlenrisiko

    Energy Technology Data Exchange (ETDEWEB)

    Jung, H. [Hamburg Univ. (Germany). Inst. fuer Biophysik und Strahlenbiologie

    1998-10-01

    Breast cancer is the most frequent malignant neoplasia among women in Germany. The use of mammography as the most relevant diagnostic procedure has increased rapidly over the last decade. Radiation risks associated with mammography may be estimated from the results of numerous epidemiological studies providing risk coefficients for breast cancer in relation to age at exposure. Various calculations can be performed using the risk coefficients. For instance, a single mammography examination (bilateral, two views of each breast) of a women aged 45 may enhance the risk of developing breast cancer during her lifetime numerically from about 12% of 12.0036%. This increase in risk is lower by a factor of 3,300 as compared to the risk of developing breast cancer in the absence of radiation exposure. At the age of 40 or more, the benefit of mammography exceeds the radiation risk by a factor of about 100. At higher ages this factor increases further. Finally, the dualism of individual risk and collective risk is considered. It is shown that the individual risk of a patient, even after multiple mammography examinations, is vanishingly small. Nevertheless, the basic principle of minimising radiation exposure must be followed to keep the collective risk in the total population as low as reasonably achievable. (orig.) [Deutsch] Das Mammakarzinom ist in Deutschland die haeufigste Krebserkrankung der Frau, und entsprechend oft wird die Mammographie als das derzeit wichtigste Diagnoseverfahren eingesetzt. Zur Beurteilung des mit einer mammographischen Untersuchung verbundenen Strahlenrisikos liegen die Resultate einer groesseren Anzahl strahlenepidemiologischer Studien vor. Diese liefern den Risikokoeffizienten fuer Brustkrebs in Abhaengigkeit vom Lebensalter bei Strahlenexposition und ermoeglichen somit die Berechnung des altersabhaengigen Strahlenrisikos. Beispielsweise wird durch eine einmalige Mammographie-Untersuchung (bilateral, je zwei Aufnahmen in zwei Ebenen) bei einer 45

  16. Digital mammography

    International Nuclear Information System (INIS)

    Bick, Ulrich; Diekmann, Felix

    2010-01-01

    This state-of-the-art reference book provides in-depth coverage of all aspects of digital mammography, including detector technology, image processing, computer-aided diagnosis, soft-copy reading, digital workflow, and PACS. Specific advantages and disadvantages of digital mammography in comparison to screen-film mammography are thoroughly discussed. By including authors from both North America and Europe, the book is able to outline variations in the use, acceptance, and quality assurance of digital mammography between the different countries and screening programs. Advanced imaging techniques and future developments such as contrast mammography and digital breast tomosynthesis are also covered in detail. All of the chapters are written by internationally recognized experts and contain numerous high-quality illustrations. This book will be of great interest both to clinicians who already use or are transitioning to digital mammography and to basic scientists working in the field. (orig.)

  17. Ultrasonic mammography

    International Nuclear Information System (INIS)

    Hueneke, B.

    1982-01-01

    608 women are examined by means of ultrasonic mammography during the period of 1 year. 432 patients were examined with the compound method with the U.I. Octoson, a water tank scanner, and 176 patients with the real time method with a directly connected linear-array-scanner. The following results were obtained at the end of the examination period: In the ultrasonic and also in the X-ray mammogram tumour diameters can be determined with an error rate of +- 30%. In the diagnosing of carcinomas, a significant dependence of the exactness on the sice of the tumour is found for the combination of the five methods tested (clinical examination, X-ray mammography, ultrasonic mammography, thermography, cytology). Classifying the individual methods with regard to their exactness, X-ray mammography ranks in front of ultrasonic mammography. Mastopathic changes in the breast can be screened by means of ultrasonic mammography. The structure of the changes can be determined more exactly than with an X-ray picture which is due to the possibility of differentiating solid and cystic structures. In diagnosing fibro-adenomas and establishing diagnoses on young women with dense gland bodies, ultrasonic mammography is superior to radiology both in the ability of screening a finding of a fibro-adenoma (US=88%, X-ray=75%) and in the possibility of classifying it as ''more benign than malignant''. (orig./MG) [de

  18. Clinical experience of photon counting breast tomosynthesis: comparison with traditional mammography

    International Nuclear Information System (INIS)

    Svane, Gunilla; Azavedo, Edward; Lindman, Karin; Urech, Mattias; Nilsson, Jonas; Weber, Niclas; Lindqvist, Lars; Ullberg, Christer

    2011-01-01

    Background: In two-dimensional mammography, a well-known problem is over- and underlying tissue which can either obstruct a lesion or create a false-positive result. Tomosynthesis, with an ability to layer the tissue in the image, has the potential to resolve these issues. Purpose: To compare the diagnostic quality, sensitivity and specificity of a single tomosynthesis mammography image and a traditional two-view set of two-dimensional mammograms and to assess the comfort of the two techniques. Material and Methods: One hundred and forty-four women, mainly chosen because of suspicious features on standard mammograms (76 malignant), had a single tomosynthesis image taken of one breast using a novel photon counting system. On average, the dose of the tomosynthesis images was 0.63 times that of the two-view images and the compression force during the procedure was halved. The resulting images were viewed by two radiologists and assessed both individually and comparing the two techniques. Results: In 56% of the cases the radiologists rated the diagnostic quality of the lesion details higher in the tomosynthesis images than in the conventional images (and in 91% equal or higher), which means there is a statistically significant preference for the tomosynthesis technique. This included the calcifications which were rated as having better quality in 41% of the cases. While sensitivity was slightly higher for traditional mammography the specificity was higher for tomosynthesis. However, neither of these two differences was large enough to be statistically significant. Conclusion: The overall accuracy of the two techniques was virtually equal despite the radiologist's very limited experience with tomosynthesis images and vast experience with two-dimensional mammography. As the diagnostic quality of the lesion details in the tomosynthesis images was valued considerably higher this factor should improve with experience. The patients also favored the tomosynthesis examination

  19. Mammography Facilities

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Mammography Facility Database is updated periodically based on information received from the four FDA-approved accreditation bodies: the American College of...

  20. Advanced Breast Cancer as Indicator of Quality Mammography

    International Nuclear Information System (INIS)

    Gaona, Enrique

    2003-01-01

    Breast cancer is the most frequently diagnosed cancer and is the second leading cause of cancer death among women in the Mexican Republic. Mammography is the more important screening tool for detecting early breast cancer. Screening mammography involves taking x-rays from two views from each breast, typically from above (cranial-caudal view, CC) and from an oblique or angled view (mediolateral-oblique, MLO). The purpose of this study was to carry out an exploratory survey of the issue of patients with advanced breast cancer who have had a screening mammography. A general result of the survey is that 22.5% of all patients (102) with advanced breast cancer that participated in the study had previous screening mammography. But we should consider that 10% of breast cancers are not detected by mammography. Only 70% of the family doctors prescribed a diagnostic mammography when the first symptoms were diagnosed

  1. A comparison of the accuracy of film-screen mammography, full-field digital mammography, and digital breast tomosynthesis

    International Nuclear Information System (INIS)

    Michell, M.J.; Iqbal, A.; Wasan, R.K.; Evans, D.R.; Peacock, C.; Lawinski, C.P.; Douiri, A.; Wilson, R.; Whelehan, P.

    2012-01-01

    Aim: To measure the change in diagnostic accuracy of conventional film-screen mammography and full-field digital mammography (FFDM) with the addition of digital breast tomosynthesis (DBT) in women recalled for assessment following routine screening. Materials and methods: Ethics approval for the study was granted. Women recalled for assessment following routine screening with screen-film mammography were invited to participate. Participants underwent bilateral, two-view FFDM and two-view DBT. Readers scored each lesion separately for probability of malignancy on screen-film mammography, FFDM, and then DBT. The scores were compared with the presence or absence of malignancy based on the final histopathology outcome. Results: Seven hundred and thirty-eight women participated (93.2% recruitment rate). Following assessment 204 (26.8%) were diagnosed as malignant (147 invasive and 57 in-situ tumours), 286 (37.68%) as benign, and 269 (35.4%) as normal. The diagnostic accuracy was evaluated by using receiving operating characteristic (ROC) and measurement of area under the curve (AUC). The AUC values demonstrated a significant (p = 0.0001) improvement in the diagnostic accuracy with the addition of DBT combined with FFDM and film-screen mammography (AUC = 0.9671) when compared to FFDM plus film-screen mammography (AUC = 0.8949) and film-screen mammography alone (AUC = 0.7882). The effect was significantly greater for soft-tissue lesions [AUC was 0.9905 with the addition of DBT and AUC was 0.9201 for FFDM with film-screen mammography combined (p = 0.0001)] compared to microcalcification [with the addition of DBT (AUC = 0.7920) and for FFDM with film-screen mammography combined (AUC = 0.7843; p = 0.3182)]. Conclusion: The addition of DBT increases the accuracy of mammography compared to FFDM and film-screen mammography combined and film-screen mammography alone in the assessment of screen-detected soft-tissue mammographic abnormalities.

  2. The accuracy of digital breast tomosynthesis compared with coned compression magnification mammography in the assessment of abnormalities found on mammography

    International Nuclear Information System (INIS)

    Morel, J.C.; Iqbal, A.; Wasan, R.K.; Peacock, C.; Evans, D.R.; Rahim, R.; Goligher, J.; Michell, M.J.

    2014-01-01

    Aim: To compare the diagnostic accuracy of the digital breast tomosynthesis (DBT) with coned compression magnification mammography (CCMM). Materials and methods: The study design included two reading sessions completed by seven experienced radiologists. In the first session, all readers read bilateral standard two-view mammograms and a CCMM view of the lesion before giving a combined score for assessment. In the second session, readers read bilateral standard two-view mammograms plus one-view DBT. The two reading sessions of the experiment were separated by at least 2 weeks to reduce the chance of reader memory of the images read in the previous session from influencing the performance in the subsequent session. Results: Three hundred and fifty-four lesions were assessed and receiver-operative characteristic (ROC) analysis was used to evaluate the difference between the two modes. For standard two-view mammography plus CCMM, the area under the curve (AUC) was 0.87 [95% confidence interval (CI): 0.83–0.91] and for standard two-view mammography plus DBT the AUC was 0.93 (95% CI: 0.91–0.95). The difference between the AUCs was 0.06 with p-value of 0.0014. Conclusion: Two-view mammography with one-view DBT showed significantly improved accuracy compared to two-view mammography and CCMM in the assessment of mammographic abnormalities. These results show that DBT can be used effectively in the further evaluation of mammographic abnormalities found at screening and in symptomatic diagnostic practice. - Highlights: • Diagnostic accuracy of magnification mammography and digital breast tomosynthesis. • There is statistical difference between CCMM and DBT. • DBT has a role in evaluating mammographic abnormalities

  3. Quality control of mammography departments in Slovakia

    International Nuclear Information System (INIS)

    Horvathova, M.; Nikodemova, D.

    2007-01-01

    Complete test of publication follows. Considering the fact that mammary gland is the most sensitive organ to ionizing radiation, the Commission of the Ministry of Health of SR for QA in radiology organized a pilot two-run country wide audit conducted in 42 mammography departments that have met the beforehand criteria. During the audit the methods for establishing the individual parameters in technical and clinical part of quality assurance in mammography were elaborated and implemented. Technical and clinical parameters of the imaging process that mostly affect the quality of diagnostic information were followed up. These parameters included: the object thickness compensation, optical density deviation, evaluation of the film quality by means of special phantom, etc. Important measurement of ESDs at participating departments enabled to compare the radiation load of mammography patients in Slovakia with reference values in European guidelines. The uniform standard method for QA at mammography departments was elaborated and published as the regulation of the Ministry of Health for performance of preventive mammography examinations in SR. The presented results show the improved quality of mammography examinations due to regular check-ups of technical and clinical parameters and fulfilment of the required values in all parameters. The audit results are the basis for continuous quality assessment of mammography departments as a main prerequisite for conducting preventive examinations and for health insurance purposes.

  4. The effect of changing from one to two views at incident (subsequent) screens in the NHS breast screening programme in England: impact on cancer detection and recall rates

    International Nuclear Information System (INIS)

    Blanks, R.G.; Bennett, R.L.; Patnick, J.; Cush, S.; Davison, C.; Moss, S.M.

    2005-01-01

    AIM: To assess the effect on cancer detection and recall rates of changing from one to two views for incident (subsequent) screens. METHODS: Controlled, comparative, observational study of programmes in NHS breast screening programme in England. Subjects: women aged 50-64 years were screened by the NHSBSP between 1 April 2001 and 31 March 2003. RESULTS: The effect of changing to two-view mammography was a 20% increase in overall incident screen cancer detection rate, with the biggest effect seen for small (<15 mm) invasive cancers. This increased detection rate was achieved with an 11% drop-in recall rate. CONCLUSION: The introduction of two-view mammography for incident screens has resulted in considerable improvements in overall NHS breast screening performance

  5. Mammography fixture

    International Nuclear Information System (INIS)

    Henkes, J.L. Jr.

    1979-01-01

    A device is described for compressing a pendant breast during tomographic mammography using X-rays. The device utilises a thin, elastic membrane pressurised by a fluid whose X-ray absorption properties are similar to those of soft human tissue. The membrane changes the normal conical shape of a pendant breast into a substantially cylindrical shape. The breast is surrounded by a second fluid medium whose X-ray absorption properties are also similar to that of soft human tissue and tomography transmission is carried out through the second fluid medium and the breast. This patent claims the advantages of eliminating high gradients in X-ray absorption density and the effective detection of breast tumours with minimum radiation dosage and processing time. (UK)

  6. Influence of the radiographer on the pain felt during mammography

    International Nuclear Information System (INIS)

    Goethem, M. van; Verslegers, I.; Biltjes, I.; De Schepper, A.; Mortelmans, D.; Bruyninckx, E.; Hove, E. Van

    2003-01-01

    Mammography is the only useful examination in screening for breast cancer. Mortality from breast cancer can be reduced if women go regularly for a screening mammography. Moreover, it is still the key examination in diagnosis of breast diseases and in the follow-up of patients treated for breast cancer. Pain with mammography can deter women from going for regular screening or follow-up; therefore, it is important to reduce pain experience or discomfort from mammography. In this study we evaluate the impact of the ''radiographer'' on the pain risk during mammography by analysing questionnaires filled in by women and radiographers. Study results reveal that the opinion of the radiographer, the information and communication during the examination and the number of years of experience are important factors in pain and discomfort experience. The attitude of the radiographer plays an important role in the pain experience. (orig.)

  7. Magnification mammography

    International Nuclear Information System (INIS)

    Sickles, E.A.

    1987-01-01

    Lack of detail, a situation commonly encountered, renders unreliable the diagnostic criteria described above, leading to equivocal radiographic interpretations. Standard practice calls for biopsy of such equivocal lesions in order to rule out malignancy; indeed, this is necessary to detect as many small cancers as possible. An unfortunate consequence of this approach, however, is that several benign lesions have to be removed for each cancer discovered. In some circumstances, especially when malignancy is thought to be unlikely, biopsy is deferred in favor of a series of follow-up mammographic examinations. It is even more unfortunate, if this latter course of action is chosen, when the underlying lesion proves to be cancerous and appropriate treatment is thereby delayed. One potential solution to this double-edged problem of equivocal interpretations is to substantially improve the sharpness and detail of the radiographic image, thus permitting one to utilize more fully the standard mammographic interpretive criteria that otherwise might be ignored. If this approach proves successful, some equivocal interpretations will be converted into more definitive diagnoses, either benign or malignant. The technique of direct radiographic magnification has been shown to be very helpful in this regard. Not only are magnification images known to display improved sharpness and detail, but magnification techniques have already been applied successfully to mammography, angiography, and skeletal radiography, resulting in increased diagnostic accuracy for these examinations

  8. Digital breast tomosynthesis versus digital mammography: a clinical performance study

    International Nuclear Information System (INIS)

    Gennaro, Gisella; Baldan, Enrica; Bezzon, Elisabetta; Polico, Ilaria; Proietti, Alessandro; Toffoli, Aida; Toledano, Alicia; Di Maggio, Cosimo; La Grassa, Manuela; Pescarini, Luigi; Muzzio, Pier Carlo

    2010-01-01

    To compare the clinical performance of digital breast tomosynthesis (DBT) with that of full-field digital mammography (FFDM) in a diagnostic population. The study enrolled 200 consenting women who had at least one breast lesion discovered by mammography and/or ultrasound classified as doubtful or suspicious or probably malignant. They underwent tomosynthesis in one view [mediolateral oblique (MLO)] of both breasts at a dose comparable to that of standard screen-film mammography in two views [craniocaudal (CC) and MLO]. Images were rated by six breast radiologists using the BIRADS score. Ratings were compared with the truth established according to the standard of care and a multiple-reader multiple-case (MRMC) receiver-operating characteristic (ROC) analysis was performed. Clinical performance of DBT compared with that of FFDM was evaluated in terms of the difference between areas under ROC curves (AUCs) for BIRADS scores. Overall clinical performance with DBT and FFDM for malignant versus all other cases was not significantly different (AUCs 0.851 vs 0.836, p = 0.645). The lower limit of the 95% CI or the difference between DBT and FFDM AUCs was -4.9%. Clinical performance of tomosynthesis in one view at the same total dose as standard screen-film mammography is not inferior to digital mammography in two views. (orig.)

  9. Mammography discomfort: a holistic perspective derived from women's experiences

    International Nuclear Information System (INIS)

    Poulos, Ann; Llewellyn, Gwynnyth

    2005-01-01

    Purpose: Mammography discomfort has the potential to deter women from attending for regular breast screening. Previous studies have focussed on the pain/discomfort of the mammography procedure itself. The purpose of this study was to consider discomfort from a holistic perspective of the mammography experience derived from the women themselves. Methods: Qualitative research methods were employed. Using theoretical sampling, 12 women who had recently experienced mammography were interviewed. The interview questions aimed to explore the experience of women attending for a mammogram from arrival to departure and beyond in order to identify aspects which potentially increase discomfort. Data analysis involved coding and categorisation and identification of key concepts and their relationships. Results: A conceptual framework was developed that demonstrates the contributors to mammography discomfort and the relationships between these as identified by the women. Conclusions: The conceptual framework has important implications for clinical practice and future research

  10. Experience with digital mammography

    Directory of Open Access Journals (Sweden)

    G. P. Korzhenkova

    2011-01-01

    Full Text Available The use of digital techniques in mammography has become a last step for completing the process of digitization in diagnostic imaging. It is assumed that such a spatial decision will be required for digital mammography, as well as for high-resolution intensifying screen-film systems used in conventional mammography and that the digital techniques will be limited by the digitizer pixel size on detecting minor structures, such as microcalcifications. The introduction of digital technologies in mammography involves a tight control over an image and assures its high quality.

  11. Screen-film mammography

    International Nuclear Information System (INIS)

    Logan, W.W.; Janus, J.A.

    1987-01-01

    The development of screen-film mammography has resulted in the re-emergence of confidence, rather than fear, in mammography. When screen-film mammography is performed with state-of-the-art dedicated equipment utilizing vigorous breast compression and a ''soft'' x-ray beam for improved contrast, screen-film images are equivalent or superior to those of reduced-dose xeromammography and superior to those of nonscreen film mammography. Technological aids for conversion from xeromammographic or nonscreen film mammographic techniques to screen-film techniques have been described. Screen-film mammography should not be attempted until dedicated equipment has been obtained and the importance of vigorous compression has been understood

  12. Digital mammography; Mamografia digital

    Energy Technology Data Exchange (ETDEWEB)

    Chevalier, M.; Torres, R.

    2010-07-01

    Mammography represents one of the most demanding radiographic applications, simultaneously requiring excellent contrast sensitivity, high spatial resolution, and wide dynamic range. Film/screen is the most widely extended image receptor in mammography due to both its high spatial resolution and contrast. The film/screen limitations are related with its narrow latitude, structural noise and that is at the same time the medium for the image acquisition, storage and presentation. Several digital detector made with different technologies can overcome these difficulties. Here, these technologies as well as their main advantages and disadvantages are analyzed. Also it is discussed its impact on the mammography examinations, mainly on the breast screening programs. (Author).

  13. Quality assurance in mammography

    International Nuclear Information System (INIS)

    Fosmark, H.; Olerud, H.M.

    1992-01-01

    Guidelines in mammography are given, including competence of staff, performance of equipment and quality control procedures. The purpose of the guidelines is to ensure optimum diagnostic quality. 5 refs

  14. Quality assurance programme at Slovak mammography departments

    International Nuclear Information System (INIS)

    Horvathova, M.; Nikodemova, D.

    2004-01-01

    evaluation of phantom (a minimum of the 4 largest fibres, 3 largest speck groups and 3 largest masses must be visible) are shown. The preliminary results of the pilot mammography audit in Slovakia have shown: 1) Important reduction in patient doses and remarkable improvements in image quality can be achieved by the practical application of the co-ordinated QC program; 2) The measurements of ESD can be performed in the tolerance limit of 10 %; 3) The regular measurement of performance indicators (AEC control) call attention to faults causing the deviations of acceptable tolerance levels; 4) Clinical image evaluation of experts enables improvement of final diagnosis estimation

  15. Digital Mammography in Young Women: Is a Single View Sufficient?

    Science.gov (United States)

    Gossner, Johannes

    2016-03-01

    Single view mammography may be a less time consuming, more comfortable and radiation reduced alternative for young women, but there are no studies examining this approach after the implementation of digital mammography into clinical practice. Retrospective analysis of all mammographies performed in women younger than 40 years during a 24 month period. The sample consisted of 109 women with 212 examined breasts. All patients initially received standard two- view mammography. In the study setting the MLO- views were read by a single viewer and compared to a composite reference standard. In this sample 7 malignant findings were present and the review of the MLO-view detected 6 of them (85%). In patients with dense breasts 4 out of 5 malignant findings were found on the single-view (sensitivity 80%) and all 2 malignant findings were detected in patients with low breast density (sensitivity 100%). There were 7 false positive findings (3.3%). i.e. in total 8 out of 212 examined breasts were therefore misinterpreted (3.8%). Single view digital mammography detects the vast majority of malignant findings, especially in low density breast tissue and the rate of false-positive findings is within acceptable limits. Therefore this approach may be used in different scenarios (for example in increasing patient throughout in resource poor settings, reducing radiation burden in the young or in combination with ultrasound to use the strengths of both methods). More research on this topic is needed to establish its potential role in breast imaging.

  16. Cultural views, language ability, and mammography use in Chinese American women.

    Science.gov (United States)

    Liang, Wenchi; Wang, Judy; Chen, Mei-Yuh; Feng, Shibao; Yi, Bin; Mandelblatt, Jeanne S

    2009-12-01

    Mammography screening rates among Chinese American women have been reported to be low. This study examines whether and how culture views and language ability influence mammography adherence in this mostly immigrant population. Asymptomatic Chinese American women (n = 466) aged 50 and older, recruited from the Washington, D.C. area, completed a telephone interview. Regular mammography was defined as having two mammograms at age-appropriate recommended intervals. Cultural views were assessed by 30 items, and language ability measured women's ability in reading, writing, speaking, and listening to English. After controlling for risk perception, worry, physician recommendation, family encouragement, and access barriers, women holding a more Chinese/Eastern cultural view were significantly less likely to have had regular mammograms than those having a Western cultural view. English ability was positively associated with mammography adherence. The authors' results imply that culturally sensitive and language-appropriate educational interventions are likely to improve mammography adherence in this population.

  17. Nasoduodenal tube placement: Are two views necessary to confirm position?

    International Nuclear Information System (INIS)

    Ngo, Anh-Vu; Done, Stephen; Otto, Randolph; Friedman, Seth; Stanescu, A.L.

    2017-01-01

    Nasoduodenal tube (NDT) placement is typically performed at the bedside and two-view abdominal radiographs are usually used to confirm tube position. Anecdotally, in most instances the lateral view is unnecessary and utilizes more than twice the radiation than an anteroposterior (AP) view alone. We hypothesize that NDT location can be determined using only the AP view, with the NDT position determined on two views utilized as the gold standard. A search was performed for all two- or three-view abdominal radiographs from September 2012 to September 2013 with the phrase ''ND tube'' in the reason field of the requisition. These studies were independently reviewed by two radiologists and scored for anatomical tube position in three different scenarios: AP view alone, the lateral view alone, and both views together, with the latter serving as the gold standard. The anatomical scores were subsequently grouped to reflect clinically significant scenarios. Comparative analysis was performed with the original and clinically grouped scores. A total of 102 patients and 306 separate two-view exams were evaluated. Of the 102 patients, 55 had at least two separate exams. Across raters, concordances of AP and lateral scores relative to the gold standard assessment were 88% and 73% for anatomical scores, and 91.5% and 86.4% for clinically grouped data. Trend differences for fewer errors were found with the AP compared to the lateral view. There were statistically significant group differences with a greater number of false-negative errors in the lateral data set. No clear differences were found when comparing AP and lateral ratings for false-positive errors. Upon review of the common errors, we determined a few imaging findings on AP radiographs that can help assess the need for an additional lateral view. A single AP view is sufficient to determine the NDT position in most cases. Two views should be reserved for cases where the NDT position cannot be

  18. Nasoduodenal tube placement: Are two views necessary to confirm position?

    Energy Technology Data Exchange (ETDEWEB)

    Ngo, Anh-Vu; Done, Stephen; Otto, Randolph; Friedman, Seth; Stanescu, A.L. [Seattle Children' s Hospital, Department of Radiology, Seattle, WA (United States)

    2017-09-15

    Nasoduodenal tube (NDT) placement is typically performed at the bedside and two-view abdominal radiographs are usually used to confirm tube position. Anecdotally, in most instances the lateral view is unnecessary and utilizes more than twice the radiation than an anteroposterior (AP) view alone. We hypothesize that NDT location can be determined using only the AP view, with the NDT position determined on two views utilized as the gold standard. A search was performed for all two- or three-view abdominal radiographs from September 2012 to September 2013 with the phrase ''ND tube'' in the reason field of the requisition. These studies were independently reviewed by two radiologists and scored for anatomical tube position in three different scenarios: AP view alone, the lateral view alone, and both views together, with the latter serving as the gold standard. The anatomical scores were subsequently grouped to reflect clinically significant scenarios. Comparative analysis was performed with the original and clinically grouped scores. A total of 102 patients and 306 separate two-view exams were evaluated. Of the 102 patients, 55 had at least two separate exams. Across raters, concordances of AP and lateral scores relative to the gold standard assessment were 88% and 73% for anatomical scores, and 91.5% and 86.4% for clinically grouped data. Trend differences for fewer errors were found with the AP compared to the lateral view. There were statistically significant group differences with a greater number of false-negative errors in the lateral data set. No clear differences were found when comparing AP and lateral ratings for false-positive errors. Upon review of the common errors, we determined a few imaging findings on AP radiographs that can help assess the need for an additional lateral view. A single AP view is sufficient to determine the NDT position in most cases. Two views should be reserved for cases where the NDT position cannot be

  19. Practical digital mammography

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Beverly E. [Washington Univ., Seattle, WA (United States)]|[Virginia Mason Medical Center, VA (United States)

    2008-07-01

    This book is meant for the radiologist who is facing the challenge of organizing a digital mammographic imaging center. This text is meant to be a practical book that provides information about digital mammographic physics and equipment which will allow one to intelligently compare technologies and systems. Some of the major challenges include: large expense; rapidly changing technology, and inconsistent connectivity; and finally, need for strong information technology support. The initial conversion cost to digital mammographic imaging is relatively expensive due to the cost of digital mammography hardware, software, and storage. Virtually all other imaging modalities are being converted to purely digital storage and transfer, and the digital trend in mammography is inevitable. Technical advantages of digital mammography are described. However, the improved flexibility in image display and transfer are some of its strongest features. In conclusion, although there are increasing imaging modalities that may be used to evaluate breast disease, mammography will continue to play a key role in detecting breast cancer. To be an effective imager, the radiologist should become familiar with digital mammography and understand its role within the increasing complex structure of breast imaging techniques.

  20. Practical digital mammography

    International Nuclear Information System (INIS)

    Hashimoto, Beverly E.

    2008-01-01

    This book is meant for the radiologist who is facing the challenge of organizing a digital mammographic imaging center. This text is meant to be a practical book that provides information about digital mammographic physics and equipment which will allow one to intelligently compare technologies and systems. Some of the major challenges include: large expense; rapidly changing technology, and inconsistent connectivity; and finally, need for strong information technology support. The initial conversion cost to digital mammographic imaging is relatively expensive due to the cost of digital mammography hardware, software, and storage. Virtually all other imaging modalities are being converted to purely digital storage and transfer, and the digital trend in mammography is inevitable. Technical advantages of digital mammography are described. However, the improved flexibility in image display and transfer are some of its strongest features. In conclusion, although there are increasing imaging modalities that may be used to evaluate breast disease, mammography will continue to play a key role in detecting breast cancer. To be an effective imager, the radiologist should become familiar with digital mammography and understand its role within the increasing complex structure of breast imaging techniques

  1. Image quality in mammography

    International Nuclear Information System (INIS)

    Haus, A.G.; Doi, K.; Metz, C.E.; Bernstein, J.

    1976-01-01

    In mammography, image quality is a function of the shape, size, and x-ray absorption properties of the anatomic part to be radiographed and of the lesion to be detected; it also depends on geometric unsharpness, and the resolution, characteristic curve and noise properties of the recording system. X-ray energy spectra, modulation transfer functions, Wiener spectra, characteristic and gradient curves, and radiographs of a breast phantom and of a resected breast specimen containing microcalcifications are used in a review of some current considerations of the factors, and the complex relationship among factors, that affect image quality in mammography. Image quality and patient radiation exposure in mammography are interrelated. An approach to the problem of evaluating the trade-off between diagnostic certainty and the cost or risk of performing a breast imaging procedure is discussed

  2. Teaching atlas of mammography

    International Nuclear Information System (INIS)

    Tabar, L.; Dean, P.B.

    1985-01-01

    The illustrated case reports in this teaching atlas cover practically the entire range of possible pathological changes and are based on in-patient case material and 80,000 screening documents. The two basic approaches, - detection and analysis of changes -, are taught comprehensively and in great detail. A systematic procedure for analysing the mammographies, in order to detect even the very least changes, and its practical application is explained using mammographies showing unclear findings at first sight. A system of coordinates is presented which allows precise localisation of the changes. Exercises for practising the technique of identifying the pathological changes round up the methodolical chapters. Additional imaging technical enhancements and detail enlargements are of great help in interpreting the findings. The specific approach adopted for this teaching atlas is a 'reverse procedure', which leaves the beaten track and starts with analysing the mammographies and evaluating the radiographic findings, in order to finally derive the diagnosis. (orig./CB) [de

  3. Breast cancer screening: the underuse of mammography

    International Nuclear Information System (INIS)

    Fox, S.; Baum, J.K.; Klos, D.S.; Tsou, C.V.

    1985-01-01

    The early detection of breast cancer is promoted by the American Cancer Society (ACS) and the American College of Radiology (ACR) by encouraging the regular use of three types of screening: breast self-examination (BSE), the clinical breast examination, and mammography. In August 1983, the ACS publicized seven recommendations pertaining to screening, including a revised statement about the routine use of mammography for women between the ages of 40 and 49 years. In response to the ACS statement, the present study assessed compliance with the updated recommendations for all three types of screening. The results show reasonable rates of compliance for the BSE (53%-69%) and clinical examination (70%-78%). In contrast, only 19% of the women between the ages of 35 and 49 and 25% of the women older than 50 reported complying with the recommendation to undergo one baseline screening mammogram. Some implications for health education by physicians and the professional education of physicians in the use of mammography are discussed

  4. Evaluation of the performance characteristic for mammography by using edge device

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Won [Dept. of Radiology, Kyung Hee University Hospital at Gang-dong, Seoul (Korea, Republic of); Choi, Jwan Woo [Dept. of Radiology, Asan Medical Center, Seoul (Korea, Republic of); Jeong, Hoi Woun [Dept. of Radiological Technology, The Baekseok Culture University, Cheonan (Korea, Republic of); Jang, Seo Goo [Dept. of Medical Science, The Soonchunhyang University, Asan (Korea, Republic of); Lee, Eul Kyu [Dept. of Radiology, Inje Paik University Hospital Jeo-dong, Seoul (Korea, Republic of); Son, Soon Yong [Dept. of Radiological Technology, The Wonkwang Health Science University, Iksan (Korea, Republic of); Son, Jin Hyun; Min, Jung Whan [Dept. of Radiological Technology, The Shingu University, Sungnam (Korea, Republic of)

    2016-09-15

    The purpose of this study was to evaluation of the performance characteristic for mammography by using edge device that mammography equipment improves essential in the correct diagnosis for the maintenance. We measured the modulation transfer function (MTF), the noise power spectrum (NPS), and the detective quantum efficiency (DQE) using the 61267 RQA-M2 based on commission standard international electro-technical commission (IEC). As a results, spatial resolution of dimensions tomo and lorad selenia mammography were maintained at 10 mm-1 and NPS and DQE including the low nyquist frequency indicated to 6.0 mm-1. Therefore, regularly QA of mammography system should be necessary. This study can be contribute to evaluate QA for performance characteristic of mammography of DDR system.

  5. Dose measurements in mammography

    International Nuclear Information System (INIS)

    Kainberger, F.; Kallinger, W.

    1977-01-01

    Dose measurements at the mamma during mammography were carried out in the form of direct measurement with thermoluminescent dosimetry. Measurement was done for the in- and outcoming doses at the mamma, the dose exposure of the sternal region and the scattered rays above the symphysis, the latter as parameter for the genetic radiation exposure. As expected, the dose of the smooth radiation used for mammography showed a strong decrease at the outcome point in comparison with the income point. Surprisingly high was the scattered radiation in the sternal region. A corresponding protection by lead plates could be taken into consideration. Extremely low is the scattered radiation above the symphysis. Even measurements with the very sensitive calcium fluoride dosimeters did not reveal any practically important dose in the symphysis region. Most measurement values remained below the determinable dose of 0.3mR. Some maximal values varied in the range of 3-1 mR. (orig.) [de

  6. Hardware for mammography

    International Nuclear Information System (INIS)

    Rozhkova, N.I.; Chikirdin, Eh.G.; Ryudiger, Yu.G.; Kochetova, G.P.; Lisachenko, I.V.; Yakobs, O.Eh.

    2000-01-01

    The comparative studies on various visualization means, in particular, the intensifying screens and films with application of quantitative methods for determining small details on photographs, including measurements of corresponding exposures, absorbed doses and verification of conclusions through the analysis of clinical observations are carried out. It is shown, that technical equipment of the modern mammography room should include the X-ray mammographic apparatus, providing for the image high-quality by low dose loads with special film holders, meeting the mammography requirements, the corresponding X-ray film and the automatic photolaboratory process, provided by one and the same company. The quality of photographs under such conditions is guarantied, the defects and errors by the image interpretation are excluded. The modern computerized information technologies for work with medical images on the basic of creating new generations of diagnostic instrumentation with digital video channels and computerized working places dispose of many medical, technological, organizational and financial problems [ru

  7. Current status of mammography

    International Nuclear Information System (INIS)

    Crymes, J.E.

    1979-01-01

    Great progress has been made in recent years in the diagnosis and treatment of breast cancer; however, breast cancer continues to be the most common and lethal cancer in women today. Early diagnosis is essential in order for treatmet to be given before the tumor spreads beyond the breast. The radiation risks of mammography have been greatly reduced with the use of newer low-dose techniques, and the benefits of mammography have increased because of a better understanding of the natural history of breast cancer, as well as improved methods of treatment. Radiologists must continue to take an active role in the early diagnosis of breast cancer. Continued research is needed in order to improve screening methods and to develop newer, noninvasive techniques

  8. Soft copy digital mammography

    International Nuclear Information System (INIS)

    Kim, Hak Hee

    2005-01-01

    Screen-film mammography (SFM) has been the standard method used for breast cancer screening and making a clinical diagnosis. It is a valuable modality for the detection and differentiation of breast calcifications. The advantages are the high spatital resolution, the convenient display, and inexpensiveness. However, it has some inherent limitations such as its low detective quantum efficiency and difficulty of post-processing after obtaining after an image. Digital mammography (DM) has the potential to overcome the inherent limitations of SFM. DM systems directly qualify x-ray photons and decouple the process of x-ray photon detection from the image display. The digital images can be processed by a computer and displayed in multiple formats. Thus, DM is better than SFM for the detection of mass lesions due to its high contrast resolution

  9. [Controversial attitude to mammography screening in asymptomatic women between 40 and 50 years of age].

    Science.gov (United States)

    Frischbier, H J

    1994-01-01

    The results of screening studies conducted in the United States and in Europe in females between the ages of 40 and 50 are analysed. It is shown, that the results of this study on mortality reduction are less favourable, the poorer the technique of mammography (foregoing of general two-view mammography) and the longer the time interval between two mammography screenings. Arguments are presented, that are brought forward when declining to perform general mammography screening in this age group. The author's own results, obtained in the Hamburg mammography screening study, which included from 1971 to 1986 also premenopausal women, show, that the survival rates of patients below 50 years of age with mammographically detected carcinomas of the breast do not differ from those in patients older than 50 years, according to a relevant age group classification. The advances in the technique of mammography in recent years are analysed on the basis of the author's own patient material. It is evident, that the positive predictive value has been doubled, especially in the age group between 40 and 50. An analysis of the distribution of diagnosed noninvasive carcinomas compared with the invasive carcinomas reveals, that particularly this age group has the highest percentage of identification of prognostically favourable carcinoma stages. Further analyses show, why the randomised European mammography studies could not yield a significant mortality rate improvement. A prerequisite for the inclusion of mammography screening in the legally prescribed early detection of carcinoma examinations, however, are the quality controls, whose realisation, in our health system, will have to be confirmed by the German mammography study.

  10. Mammography accreditation program

    Energy Technology Data Exchange (ETDEWEB)

    Wilcox, P.

    1993-12-31

    In the mid-1980`s, the movement toward the use of dedicated mammography equipment provided significant improvement in breast cancer detection. However, several studies demonstrated that this change was not sufficient to ensure optimal image quality at a low radiation dose. In particular, the 1985 Nationwide Evaluation of X-ray Trends identified the wide variations in image quality and radiation dose, even from dedicated units. During this time period, the American Cancer Society (ACS) launched its Breast Cancer Awareness Screening Campaign. However, there were concerns about the ability of radiology to respond to the increased demand for optimal screening examinations that would result from the ACS program. To respond to these concerns, the ACS and the American College of Radiology (ACR) established a joint committee on mammography screening in 1986. After much discussion, it was decided to use the ACR Diagnostic Practice Accreditation Program as a model for the development of a mammography accreditation program. However, some constraints were required in order to make the program meet the needs of the ACS. This voluntary, peer review program had to be timely and cost effective. It was determined that the best way to address these needs would be to conduct the program by mail. Finally, by placing emphasis on the educational nature of the program, it would provide an even greater opportunity for improving mammographic quality. The result of this effort was that, almost six years ago, in May 1987, the pilot study for the ACR Mammography Accreditation Program (MAP) began, and in August of that year, the first applications were received. In November 1987, the first 3-year accreditation certificates were awarded.

  11. Mammography accreditation program

    International Nuclear Information System (INIS)

    Wilcox, P.

    1993-01-01

    In the mid-1980's, the movement toward the use of dedicated mammography equipment provided significant improvement in breast cancer detection. However, several studies demonstrated that this change was not sufficient to ensure optimal image quality at a low radiation dose. In particular, the 1985 Nationwide Evaluation of X-ray Trends identified the wide variations in image quality and radiation dose, even from dedicated units. During this time period, the American Cancer Society (ACS) launched its Breast Cancer Awareness Screening Campaign. However, there were concerns about the ability of radiology to respond to the increased demand for optimal screening examinations that would result from the ACS program. To respond to these concerns, the ACS and the American College of Radiology (ACR) established a joint committee on mammography screening in 1986. After much discussion, it was decided to use the ACR Diagnostic Practice Accreditation Program as a model for the development of a mammography accreditation program. However, some constraints were required in order to make the program meet the needs of the ACS. This voluntary, peer review program had to be timely and cost effective. It was determined that the best way to address these needs would be to conduct the program by mail. Finally, by placing emphasis on the educational nature of the program, it would provide an even greater opportunity for improving mammographic quality. The result of this effort was that, almost six years ago, in May 1987, the pilot study for the ACR Mammography Accreditation Program (MAP) began, and in August of that year, the first applications were received. In November 1987, the first 3-year accreditation certificates were awarded

  12. The relationship of social support concept and repeat mammography among Iranian women.

    Science.gov (United States)

    Farhadifar, Fariba; Taymoori, Parvaneh; Bahrami, Mitra; Zarea, Shamsy

    2015-10-24

    Breast cancer ranks as the first most common cancer among the Iranian women. The regular repeat of mammography with 1-2 year intervals leads to the increased efficiency of early detection of breast cancer. The present study examined the predictors of repeat mammography. It was hypothesized that higher social support is connected with mammography repeat. A cross-sectional study was carried out among 400 women 50 years and older in Sanandaj, Iran. Data was collected by the questionnaire including information on socio demographical variables and measuring social support level. Data was analyzed by SPSS16 software. Multiple logistic regression was used to determine the predictive power of demographic variables and dimensions of social support for repeat mammography. Women aged 50-55 years had three times odds of repeat mammography compared to women aged 56-60 years) OR, 3.02). Married women had greater odds of repeat mammography compared to single women (P women with higher social support was 0.93 times greater than the women with lower social support (OR, 0.93; 95 % CI, 0.91-0.95; P women are less likely repeat mammography than other Asian women. Identifying the associations between perceived social support and repeat mammography may offer detailed information to allow for future study and guide the development of interventions not only for Iranian women but also for similar cultural that received pay too little attention to date in the breast cancer literature.

  13. Trimodel Mammography with Perfect Coregistration

    Science.gov (United States)

    2017-02-01

    background, the major confounding factor in reading mammography; the imaging characteristics suggest that this contrast mechanism would be preferable...image with enhanced edges and reduced anatomical background, the major confounding factor in reading mammography; the imaging characteristics suggest...subjects, vertebrate animals , biohazards, and/or select agents Describe significant deviations, unexpected outcomes, or changes in approved protocols

  14. MR mammography (MRM)

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, W.A.

    1993-01-01

    The book deals with MRI for the diagnostic evaluation of malignant breast lesions. A survey of methods available for breast examination, magnetic resonance mammography (MRM) is briefly explained in terms of development and technical problems encountered in the various examinations. The clinical aspects from a central part of the book, giving information relating to the various neoplasms and a comprehensive review of cases. The book concludes with a chapter discussing the interpretation of data and images, presenting examples of normal findings and of manifestations of carcinoma, fibroadenoma, cysts, mastopathies, scars due to plastic surgery, and the lactating breast. (UWA). 648 figs., 25 tabs.

  15. Mammography screening in Denmark

    DEFF Research Database (Denmark)

    Vejborg, Ilse; Mikkelsen, Ellen Margrethe; Garne, Jens Peter

    2011-01-01

    Mammography screening is offered healthy women, and a high standard on professional and organizational level is mandatory not only in the screening programme but even in the diagnostic work-up and treatment. The main goal is to achieve a substantial reduction in disease specific mortality......, but it is not possible to evaluate the effect on mortality until several years later, and continuously monitoring of the quality of all aspects of a screening programme is necessary. Based on other European guidelines, 11 quality indicators have been defined, and guidelines concerning organizational requirements...... for a Danish screening programme as well as recommendations for the radiographic and radiological work have been drawn up....

  16. Slit aperture technique for mammography

    International Nuclear Information System (INIS)

    Friedrich, M.

    1984-01-01

    Following a discussion of various principles used in the elimination of scatter, the prototype of a simple slit aperture mammography apparatus is described (modified Mammomat, Siemens). The main advantage of this technique compared with grid mammography is a halving of the radiation dose for identical image quality, using an identical film system. The technical requirements (heavy duty tube, new generator) are, however, considerable. If the film-screen systems currently in use are to remain the common systems for the future, then the development of a multi-lamellar slit diaphragm technique carries much promise for mammography. (orig.) [de

  17. Digital mammography and their developments

    International Nuclear Information System (INIS)

    Wienbeck, Susanne

    2015-01-01

    At the present time digital mammography is a satisfactory breast diagnostic imaging in clinical as well as screening mammography in defined age groups. Nevertheless it shows beside the application of ionizing radiation in women with dense breasts limitations in the detection of non calcification breast cancers. Tomosynthesis, digital contrast-enhanced mammography and breast-CT with or without contrast media lead to better results. Especially the application of contrast media for the visualisation of the tumor angiogenesis is invariably superior to all other non-contrast imaging modalities. However, the excellent results of breast MRI will be probably accessible with none of the new procedures.

  18. Digital Mammography Tomosynthesis

    International Nuclear Information System (INIS)

    Gergov, I.; Alexov, G.; Rusonov, K.

    2017-01-01

    Siemens MAMMOMAT Inspiration with Tomosynthesis enhances the diagnostic precision in mammographic screening. The apparatus has a wide-angle tomosynthesis up to 50 degrees. The Siemens breast augmentation algorithm reconstructs multiple two-dimensional breast images into three-dimensional images at the lowest doses to help detect tumors hidden from the overlapping chest tissue, allowing for a more accurate diagnosis than standard 2-dimensional digital mammography, and reducing the number of false positive results. 3D digital tomosynthesis improves the precision of detecting and diagnosing a larger number of expansive lesions, ensures better morphological mass analysis and architectural distortion, and detecting calcifications by adding digital breast tomosynthesis to the traditional two-dimensional digital mammogram of the patient. In this way, it solves the problem of overlapping parenchyma, reduces the number of unnecessary biopsies from questionable sonomammographic findings, and the need for stressful repeating procedures, which usually contributes to both better patient outcomes and cost saving. [bg

  19. Improvements in mammography

    International Nuclear Information System (INIS)

    Redington, R.W.; Henkes, J.L.

    1976-01-01

    Equipment for positioning and supporting patients during tomographic X-ray mammography is described. It is comprised of a table and fabric slings which permit the examination of a downward, pendant breast of a prone patient by allowing the breast to pass through an aperture in the table into a fluid filled container. The fluid has an X-ray absorption coefficient similar to that of soft human tissue allowing high density resolution radiography and permitting accurate detection of breast tumours. The shape of the equipment and the positioning of the patient allow the detector and X-ray source to rotate 360 0 about a vertical axis through the breast. This permits the use of relatively simple image reconstruction algorithms and a divergent X-ray geometry with multiple detectors. Successive planes of the breast are scanned by translating the detectors and source vertically to produce a three-dimensional image of the breast tissue structure. (U.K.)

  20. Adaptive regularization

    DEFF Research Database (Denmark)

    Hansen, Lars Kai; Rasmussen, Carl Edward; Svarer, C.

    1994-01-01

    Regularization, e.g., in the form of weight decay, is important for training and optimization of neural network architectures. In this work the authors provide a tool based on asymptotic sampling theory, for iterative estimation of weight decay parameters. The basic idea is to do a gradient desce...

  1. Mammography: MedlinePlus Health Topic

    Science.gov (United States)

    ... Questions (National Cancer Institute) Mammography for Women with Breast Implants (American Cancer Society) Also in Spanish Mammography: What You Need to Know (Food and Drug Administration) Nipple Aspirate Test Is ... Specifics Breast Tomosynthesis (American College of Radiology, Radiological Society of ...

  2. Pain and discomfort during mammography

    DEFF Research Database (Denmark)

    Aro, A R; Absetz-Ylöstalo, P; Eerola, T

    1996-01-01

    was the most powerful factor explaining pain and discomfort among women with earlier mammography. However, it had no effect among women without earlier mammography, for whom screening-related nervousness and perceptions of staff were crucial. Suggested interventions include better information before screening......The aim of this prospective study was to investigate associations of mammography pain and discomfort with sociodemographics, personal history and psychological and situational factors. Subjects were women with a negative screening finding (n = 883) from a random sample of 50-year-old Finnish women...... attending their first breast cancer screening. Questionnaires were sent 1 month before the screening invitation and 2 months after screening. Sixty-one per cent reported painful and 59% uncomfortable mammograms (4% severely). Linear regression analyses showed that anticipation of pain and discomfort...

  3. Radiographic techniques for digital mammography

    International Nuclear Information System (INIS)

    Horita, Katsuhei

    2007-01-01

    Since the differences in X-ray absorption between various breast tissues are small, a dedicated X-ray system for examination of the breast and a high-contrast, high-resolution screen/film system (SFM) (light-receiving system) are employed for X-ray diagnosis. Currently, however, there is a strong trend toward digital imaging in the field of general radiography, and this trend is also reflected in the field of mammographic examination. In fact, approximately 70% of facilities purchasing new mammography systems are now selecting a digital mammography system (DRM). Given this situation, this report reviews the differences between SFM and DRM and discusses the radiographic techniques and quality assurance procedures for digital mammography. (author)

  4. Mammography quality assurance in Morocco

    International Nuclear Information System (INIS)

    Zaoui, F.; Talsmat, K.; Lalaoui, K.

    2001-01-01

    The 'Centre National de l'Energie, des Sciences et des Techniques Nucleaires' (CNESTEN) realised, from February 1999 to March 2000, a quality control of 41 mammography facilities in Morocco. The protocol and standards adopted for achieving the control of elements constituting the mammography chain are those elaborated by GIM and Qualix association. Statistics and conformities results are presented. The program was performed in order to demonstrate to the practitioners in mammography field, the utility and necessity to have a national quality assurance policy. The main objective of CNESTEN is to be accredited by the Moroccan government as a reference laboratory in quality control and dose evaluation in medical imaging and radiotherapy. To achieve this goal the CNESTEN has set up Medical Physic Unit well trained and equipped with the necessary instruments. (author)

  5. Finding the minimal intervention needed for sustained mammography adherence.

    Science.gov (United States)

    Gierisch, Jennifer M; DeFrank, Jessica T; Bowling, J Michael; Rimer, Barbara K; Matuszewski, Jeanine M; Farrell, David; Skinner, Celette Sugg

    2010-10-01

    Regular adherence to mammography screening saves lives, yet few women receive regular mammograms. RCT. Participants were recruited through a state employee health plan. All were women aged 40-75 years and had recent mammograms prior to enrollment (n=3547). Data were collected from 2004 to 2009. Trial tested efficacy of a two-step adaptively-designed intervention to increase mammography adherence over 4 years. The first intervention step consisted of three reminder types: enhanced usual care reminders (EUCR); enhanced letter reminders (ELR); both delivered by mail, and automated telephone reminders (ATR). After delivery of reminders, women who became off-schedule in any of the 4 years received a second step of supplemental interventions. Three supplemental intervention arms contained priming letters and telephone counseling: barriers only (BarriCall); barriers plus positive consequences of getting mammograms (BarriConCall+); and barriers plus negative consequences of not getting mammograms (BarriConCall-). Average cumulative number of days non-adherent to mammography over 4 years based on annual screening guidelines (analyses conducted in 2009). All reminders performed equally well in reducing number of days of non-adherence. Women randomized to receive supplemental interventions had significantly fewer days of non-adherence compared to women who received EUCR (p=0.0003). BarrConCall+ and BarrConCall- conditions did not significantly differ in days non-adherent compared to women in the barriers-only condition (BarriCon). The minimal intervention needed for sustained mammography use is a combination of a reminder followed by a priming letter and barrier-specific telephone counseling for women who become off-schedule. Additional costs associated with supplemental interventions should be considered by organizations deciding which interventions to use. NCT01148875. Copyright © 2010 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  6. Quality Imaging - Comparison of CR Mammography with Screen-Film Mammography

    International Nuclear Information System (INIS)

    Gaona, E.; Azorin Nieto, J.; Iran Diaz Gongora, J. A.; Arreola, M.; Casian Castellanos, G.; Perdigon Castaneda, G. M.; Franco Enriquez, J. G.

    2006-01-01

    The aim of this work is a quality imaging comparison of CR mammography images printed to film by a laser printer with screen-film mammography. A Giotto and Elscintec dedicated mammography units with fully automatic exposure and a nominal large focal spot size of 0.3 mm were used for the image acquisition of phantoms in screen-film mammography. Four CR mammography units from two different manufacturers and three dedicated x-ray mammography units with fully automatic exposure and a nominal large focal spot size of 0.3 mm were used for the image acquisition of phantoms in CR mammography. The tests quality image included an assessment of system resolution, scoring phantom images, Artifacts, mean optical density and density difference (contrast). In this study, screen-film mammography with a quality control program offers a significantly greater level of quality image relative to CR mammography images printed on film

  7. Interdisciplinary group of mammography (IGM). Quality assurance in mammography

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    Assurance quality must be a preoccupation of each day in mammography. To be efficient and of low cost it must be discussed between radiologists and physicists; some countries like Federal Republic of Germany, Belgium, United Kingdom, Scandinavia and Netherlands engaged actions to make assurance quality a daily practice

  8. At what age should screening mammography be recommended for Asian women?

    International Nuclear Information System (INIS)

    Tsuchida, Junko; Nagahashi, Masayuki; Rashid, Omar M; Takabe, Kazuaki; Wakai, Toshifumi

    2015-01-01

    Although regular screening mammography has been suggested to be associated with improvements in the relative survival of breast cancer in recent years, the appropriate age to start screening mammography remains controversial. In November 2009, the United States Preventive Service Task Force published updated guidelines for breast cancer, which no longer support routine screening mammography for women aged 40–49 years, but instead, defer the choice of screening in that age group to the patient and physician. The age to begin screening differs between guidelines, including those from the Task Force, the American Cancer Society and the World Health Organization. It remains unclear how this discrepancy impacts patient survival, especially among certain subpopulations. Although the biological characteristics of breast cancer and peak age of incidence differ among different ethnic populations, there have been few reports that evaluate the starting age for screening mammography based on ethnicity. Here, we discuss the benefits and harm of screening mammography in the fifth decade, and re-evaluate the starting age for screening mammography taking ethnicity into account, focusing on the Asian population. Breast cancer incidence peaked in the fifth decade in Asian women, which has been thought to be due to a combination of biological and environmental factors. Previous reports suggest that Asian women in their 40s may receive more benefit and less harm from screening mammography than the age-matched non-Asian US population. Therefore, starting screening mammography at age 40 may be beneficial for women of Asian ethnicity in well-resourced countries, such as Japanese women who reside in Japan

  9. At what age should screening mammography be recommended for Asian women?

    Science.gov (United States)

    Tsuchida, Junko; Nagahashi, Masayuki; Rashid, Omar M; Takabe, Kazuaki; Wakai, Toshifumi

    2015-07-01

    Although regular screening mammography has been suggested to be associated with improvements in the relative survival of breast cancer in recent years, the appropriate age to start screening mammography remains controversial. In November 2009, the United States Preventive Service Task Force published updated guidelines for breast cancer, which no longer support routine screening mammography for women aged 40-49 years, but instead, defer the choice of screening in that age group to the patient and physician. The age to begin screening differs between guidelines, including those from the Task Force, the American Cancer Society and the World Health Organization. It remains unclear how this discrepancy impacts patient survival, especially among certain subpopulations. Although the biological characteristics of breast cancer and peak age of incidence differ among different ethnic populations, there have been few reports that evaluate the starting age for screening mammography based on ethnicity. Here, we discuss the benefits and harm of screening mammography in the fifth decade, and re-evaluate the starting age for screening mammography taking ethnicity into account, focusing on the Asian population. Breast cancer incidence peaked in the fifth decade in Asian women, which has been thought to be due to a combination of biological and environmental factors. Previous reports suggest that Asian women in their 40s may receive more benefit and less harm from screening mammography than the age-matched non-Asian US population. Therefore, starting screening mammography at age 40 may be beneficial for women of Asian ethnicity in well-resourced countries, such as Japanese women who reside in Japan. © 2015 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  10. Mammography in women under 35

    International Nuclear Information System (INIS)

    Panzarola, P.; Bellucci, M.C.

    1991-01-01

    The detection of breast cancer in women under 35 is quite an uncommon event, accounting only for 3.2-3.4% of all breast cancers. To determine the indications for mammography in women under 35, the authors correlated clinical, mammographic, and US findings with fine-needle aspiration/surgical biopsy and follow-up results in 1040 symptomatic women examined at the Center of Senology of the Istitute of Radiology - University of Perugia, Italy, from 1984 to June 1990. Of 1040 women, 482 (41.6%) had normal findings; benign disease was diagnosed in 558 (53.7%) cases, and malignant disease in 49 (4.7%). Mammography was very useful to diagnose malignancy in palpable breast lesions, as well as to suggest the need for biopsy, to detect metachronous cancer and to define lesion sizes. In inflammatory process - e.g., mastitis and abscesses - both mammography and US were capable as its remission after therapy. Galactography had a specific role in the evaluation of the mammary duct and demonstrated intraductal pathologic conditions. In the authors'experiences, mammography never showed occult breast cancers in women with no palpable breast lesions or hematic nipple discharge

  11. Digital mammography in breast cancer screening: Evaluation and innovation

    NARCIS (Netherlands)

    Bluekens, A.M.J.

    2015-01-01

    With all other imaging modalities in radiology being digitised and conventional mammography being ready to phase out the transition to digital mammography was inevitable. This thesis describes the performance of digital screening mammography and the consequences of implementation in a

  12. Psychosocial predictors of first attendance for organised mammography screening

    DEFF Research Database (Denmark)

    Aro, A R; de Koning, H J; Absetz, P

    1999-01-01

    Scale, Illness Attitude Scale, Health Locus of Control Scale, Anxiety Inventory, and Depression Inventory. Univariate and multivariate logistic regression analyses were used to predict attendance. RESULTS: Those most likely to attend were working, middle income, and averagely educated women, who had...... not had a mass mammogram recently, but who regularly visited gynaecologists, attended for Pap smear screening, practised breast self examination, and who did not smoke. Low confidence in their own capabilities in breast cancer prevention, overoptimism about the sensitivity of mammography, and perception...

  13. Breast dose variability in a bi-racial population undergoing screening mammography

    International Nuclear Information System (INIS)

    Schubauer-Berigan, M.K.; Baron, L.; Frey, G.D.; Hoel, D.G.

    2002-01-01

    This study evaluated individual and population dose variability during screening mammography among 570 white and black women in South Carolina, USA. Aspects of dosimetry that were considered include compressed breast thickness (CBT), number of films per screening session, and dose in previous or subsequent sessions. Breast dose was log-normally distributed in the population, with a geometric mean of 6.6 mGy per session. Doses were significantly higher for black women, for women with high CBT or who receive more than two views per breast, and for the mediolateral oblique, compared to the craniocaudal view. No relationship was observed between age and dose. Total dose per breast varied by a factor of 20 across the study population, but the individual's dose varied little among repeat screening sessions, especially after adjusting for the number of films received per session. These results may inform assessments of the projected risks of inducing breast cancer from screening mammography. (author)

  14. Application of phase contrast imaging to mammography

    International Nuclear Information System (INIS)

    Tohyama, Keiko; Yamada, Katsuhiko; Katafuchi, Tetsuro; Matsuo, Satoru; Morishita, Junji

    2005-01-01

    Phase contrast images were obtained experimentally by using a customized mammography unit with a nominal focal spot size of 100 μm and variable source-to-image distances of up to 1.5 m. The purpose of this study was to examine the applicability and potential usefulness of phase contrast imaging for mammography. A mammography phantom (ACR156 RMI phantom) was imaged, and its visibility was examined. The optical density of the phantom images was adjusted to approximately 1.3 for both the contact and phase contrast images. Forty-one observers (18 medical doctors and 23 radiological technologists) participated in visual evaluation of the images. Results showed that, in comparison with the images of contact mammography, the phantom images of phase contrast imaging demonstrated statistically significantly superior visibility for fibers, clustered micro-calcifications, and masses. Therefore, phase contrast imaging obtained by using the customized mammography unit would be useful for improving diagnostic accuracy in mammography. (author)

  15. CAD in breast imaging. Application in mammography and MR mammography

    International Nuclear Information System (INIS)

    Obenauer, S.; Hermann, K.P.

    2012-01-01

    Computer aided diagnosis systems (CAD-systems) are evaluated in different parts of diagnostic imaging. In breast imaging double reading which is time- and cost spending is necessary. Therefore a lot of studies evaluated the use of CAD-systems in mammography. However the rate of false-positives is too high to implement CAD-systems as double reader in routine work. In the future, improvements in this technique could perhaps change the performance of CAD-systems. (orig.)

  16. Digital mammography: current state and future aspects

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, U.; Baum, F. [Womens Health Care Center Goettingen, Diagnostisches Brustzentrum Goettingen, Goettingen (Germany); Hermann, K.P. [Georg-August-Universitaet Goettingen, Abteilung Diagnostische Radiologie, Goettingen (Germany)

    2006-01-01

    The introduction of digital technique in mammography has been the last step in completing the process of digitalization in diagnostic imaging. Meanwhile, some different digital techniques as well as a couple of different digital mammography systems were developed and have already been available for some years. In this review article, the relevant data of key studies are reported, the current status is defined, and perspectives of digital mammography are described. (orig.)

  17. The self-referred mammography patient

    International Nuclear Information System (INIS)

    Reynolds, H.E.; Jackson, V.P.

    1990-01-01

    This paper compares the demographics, knowledge, and attitudes of women who refer themselves for screening mammography with those who undergo mammography on the advice of their physicians. Four hundred eighty-five consecutive mammography patients (437 doctor preferred [DR], 48 self-referred [SR]) completed a survey during their mammography appointment. The sample population contained a wide range of socioeconomic groups. While similar in age, race, and employment status to DR patients, SR patients were significantly more likely to have a family income of more than 30,000 per year, be college graduates, and report that they were in good or excellent health

  18. Update on new technologies in digital mammography

    Directory of Open Access Journals (Sweden)

    Patterson SK

    2014-08-01

    Full Text Available Stephanie K Patterson, Marilyn A Roubidoux Division of Breast Imaging, Department of Radiology, University of Michigan Health System, Ann Arbor, MI, USA Abstract: Despite controversy regarding mammography's efficacy, it continues to be the most commonly used breast cancer-screening modality. With the development of digital mammography, some improved benefit has been shown in women with dense breast tissue. However, the density of breast tissue continues to limit the sensitivity of conventional mammography. We discuss the development of some derivative digital technologies, primarily digital breast tomosynthesis, and their strengths, weaknesses, and potential patient impact. Keywords: screening mammography, breast cancer, contrast media, digital breast tomosynthesis

  19. Mammography Screening Uptake among Female Health Care Workers in Primary Health Care Centers in Palestine - Motivators and Barriers.

    Science.gov (United States)

    Nazzal, Zaher; Sholi, Hisham; Sholi, Suha; Sholi, Mohammad; Lahaseh, Rawya

    2016-01-01

    Early detection remains the cornerstone of breast cancer control in terms of outcome and survival. Thus far the only breast cancer screening method proven effective is mammography. The awareness of female health care workers (HCW) about breast cancer prevention is of vital importance, as their beliefs and behavior may have a major impact on other women. This study was designed to assess mammography screening uptake among female healthcare workers at primary healthcare centers, and to identify the primary motivators and barriers that affect uptake results. A cross sectional study design was used to assess mammography screening by 299 female healthcare workers who completed a self-administered questionnaire that assessed demographics, screening uptake, motivators and barriers. The mean age was 46 years (within age of risk). The majority (95.1%) demonstrated adequate knowledge about breast cancer and mammography screening and 50% of the participants reported having at least one mammogram; however only 21% of them had regularly scheduled mammograms. The most frequent reported motivator was the perceived benefit that early detection of breast cancer is important for its management (89.6%), followed by the belief that mammography can detect breast cancer before its symptoms appear (84.4%). On the other hand, the most frequent barrier reported was being busy (46.7%), followed by the lack of perceived susceptibility (41.5%). Mammography screening was found to be sub-optimal in a population of HCW's with 50 % stating that they received a mammogram at least once, and a minority reported regular screening. There is a pressing need for educational programs aimed at removing the barriers that limit compliance with recommendations for mammography screening, and to emphasize the importance of early detection in breast cancer treatment. Ensuring the availability and accessibility of screening services, particularly for healthcare workers within their work settings are other

  20. UNFOLDED REGULAR AND SEMI-REGULAR POLYHEDRA

    Directory of Open Access Journals (Sweden)

    IONIŢĂ Elena

    2015-06-01

    Full Text Available This paper proposes a presentation unfolding regular and semi-regular polyhedra. Regular polyhedra are convex polyhedra whose faces are regular and equal polygons, with the same number of sides, and whose polyhedral angles are also regular and equal. Semi-regular polyhedra are convex polyhedra with regular polygon faces, several types and equal solid angles of the same type. A net of a polyhedron is a collection of edges in the plane which are the unfolded edges of the solid. Modeling and unfolding Platonic and Arhimediene polyhedra will be using 3dsMAX program. This paper is intended as an example of descriptive geometry applications.

  1. Control of quality in mammography

    International Nuclear Information System (INIS)

    2006-10-01

    The present protocol of quality control/quality assurance in mammography is the result of the work of two regional projects realised in Latin America within the frame of ARCAL with the support of the IAEA. The first is ARCAL LV (RLA/6/043) project on quality assurance/quality control in mammography studies which analysed the present situation of the mammography in the member countries of the project which include: Bolivia, Colombia, Costa Rica, Cuba, El Salvador, Guatemala, Nicaragua, Panama, Paraguay, Peru, Dominican Republic and Republic of Venezuela and the second is ARCAL XLIX (RLA/9/035) project, whose members were Brazil, Colombia, Cuba, Chile, Mexico, and Peru, worked the application of Basic Safety Standards for the protection against ionising radiation with the aim to improve radiation protection in X-ray diagnosis medical practices through the implementation of the Basic Safety Standards (BSS) related to x-ray diagnosis in selected hospitals located in each country involved in the project. The work of both projects had been consolidated and harmonized in the present publication

  2. Rayleigh imaging in spectral mammography

    Science.gov (United States)

    Berggren, Karl; Danielsson, Mats; Fredenberg, Erik

    2016-03-01

    Spectral imaging is the acquisition of multiple images of an object at different energy spectra. In mammography, dual-energy imaging (spectral imaging with two energy levels) has been investigated for several applications, in particular material decomposition, which allows for quantitative analysis of breast composition and quantitative contrast-enhanced imaging. Material decomposition with dual-energy imaging is based on the assumption that there are two dominant photon interaction effects that determine linear attenuation: the photoelectric effect and Compton scattering. This assumption limits the number of basis materials, i.e. the number of materials that are possible to differentiate between, to two. However, Rayleigh scattering may account for more than 10% of the linear attenuation in the mammography energy range. In this work, we show that a modified version of a scanning multi-slit spectral photon-counting mammography system is able to acquire three images at different spectra and can be used for triple-energy imaging. We further show that triple-energy imaging in combination with the efficient scatter rejection of the system enables measurement of Rayleigh scattering, which adds an additional energy dependency to the linear attenuation and enables material decomposition with three basis materials. Three available basis materials have the potential to improve virtually all applications of spectral imaging.

  3. Mammography screening in Greece: An exploratory survey of women's views, experiences and behaviours

    Directory of Open Access Journals (Sweden)

    Athena Kalokerinou

    2012-01-01

    Full Text Available Background: Internationally, breast cancer comprises 29% of all cancer incidences. In Greece, 1,500-1,800women die annually from breast cancer out of the 4,000 who are affected. Only 5% are detected at an early diseasestage through mammography screening.Aim: This paper presents findings from a study exploring the factors that influence Greek women’smammography screening behaviour.Methodology: Data were collected in Athens-Greece, during the period March-July 2008, from individuals whowere members of six women’s associations. One hundred and eighty six questionnaires were completed and 33interviews were conducted from a sub-sample. This paper reports the findings from the questionnaire survey.Results: Participants had a variety of demographic characteristics with 85% of them having attendedmammography screening. Only 61% of them intended to continue in the future. Τhe majority of women agreedwith a number of factors which supported their decision to participate in regular mammography screening, such asdoctors’ encouragement and mammogram efficacy to detect breast cancer at an early stage, while anxiety wasidentified as a possible inhibitor to their participation.Conclusion: Women’s mammography screening behaviour and perceptions of mammography screening appearedto be positive in relation to their participation. However, the reasons as to why a large number of women indicatedthey were unlikely to go for mammography screening again is not known, and needs further investigation.

  4. Quality control for the mammography screening program in Serbia: Physical and technical aspects

    International Nuclear Information System (INIS)

    Ciraj-Bjelac, O.; Bozovic, P.; Lazarevic, D.; Arandjic, D.; Kosutic, D.

    2012-01-01

    Breast cancer is the major cause of mortality among female population in Serbia. It is presumed that the introduction of screening programme will reduce mortality and therefore, 47 new mammography units were installed for the purpose of population-based screening program in 2011. In parallel, Quality assurance and Quality control (QC) in mammography has received increasing attention as an essential element of the successful breast cancer campaign that is for the first time initialed in Serbia. The purpose of this study is to investigate the need for and the possible implementation of the comprehensive QC programme for the mammography screening in Serbia, with special focus on physical and technical aspect. In the first phase, a QC protocols containing list of parameters, methodology, frequency of tests and reference values for screen-film, computed radiography and full-filed digital mammography) units, were developed. The second phase is focused on the initial implementation of these protocols. The paper presents results of tests of the selected parameters in 35 mammography units, with special emphasis on patient dose and image quality descriptors. After initial implementation at the beginning of the population based breast cancer screening campaign, it is essential to establish system of regular and periodic QC equipment monitoring and to ensure high quality mammograms with minimal possible radiation dose to population included in the screening. (authors)

  5. Barriers to Mammography among Inadequately Screened Women

    Science.gov (United States)

    Stoll, Carolyn R. T.; Roberts, Summer; Cheng, Meng-Ru; Crayton, Eloise V.; Jackson, Sherrill; Politi, Mary C.

    2015-01-01

    Mammography use has increased over the past 20 years, yet more than 30% of women remain inadequately screened. Structural barriers can deter individuals from screening, however, cognitive, emotional, and communication barriers may also prevent mammography use. This study sought to identify the impact of number and type of barriers on mammography…

  6. Mammography parameters: compression, dose, and discomfort

    International Nuclear Information System (INIS)

    Blanco, S.; Di Risio, C.; Andisco, D.; Rojas, R.R.; Rojas, R.M.

    2017-01-01

    Objective: To confirm the importance of compression in mammography and relate it to the discomfort expressed by the patients. Materials and methods: Two samples of 402 and 268 mammographies were obtained from two diagnostic centres that use the same mammographic equipment, but different compression techniques. The patient age range was from 21 to 50 years old. (authors) [es

  7. Coordinate-invariant regularization

    International Nuclear Information System (INIS)

    Halpern, M.B.

    1987-01-01

    A general phase-space framework for coordinate-invariant regularization is given. The development is geometric, with all regularization contained in regularized DeWitt Superstructures on field deformations. Parallel development of invariant coordinate-space regularization is obtained by regularized functional integration of the momenta. As representative examples of the general formulation, the regularized general non-linear sigma model and regularized quantum gravity are discussed. copyright 1987 Academic Press, Inc

  8. Development of diagnostic mammography unit

    Energy Technology Data Exchange (ETDEWEB)

    Matsubara, M.; Muraki, T.; Kitade, K. (Toshiba Corp., Kawasaki, Kanagawa (Japan))

    1981-07-01

    The mortality from breast cancer is gradually increasing year after year. Accordingly, it is eagerly desired that X-ray diagnosis information be obtainable with higher accuracy and ease for early detection of the disease. Meeting this demand, development has been made of a 2 x magnification mammography unit (Model MGU-01) capabel of minutely depicting microcalcifications with a size of 150 ..mu..m or thereabout and the peripheral condition of a mammary abscess. The background of the development, the substance of the unit and the examination made of the unit are described here.

  9. Development of diagnostic mammography unit

    International Nuclear Information System (INIS)

    Matsubara, Mitsuyoshi; Muraki, Takeshi; Kitade, Kooichi

    1981-01-01

    The mortality from breast cancer is gradually increasing year after year. Accordingly, it is eagerly desired that X-ray diagnosis information be obtainable with higher accuracy and ease for early detection of the disease. Meeting this demand, development has been made of a 2 x magnification mammography unit (Model MGU-01) capabel of minutely depicting microcalcifications with a size of 150 μm or thereabout and the peripheral condition of a mammary abscess. The background of the development, the substance of the unit and the examination made of the unit are described here. (author)

  10. Screen-film mammography versus full-field digital mammography in a population-based screening program: The Sogn and Fjordane study

    International Nuclear Information System (INIS)

    Juel, Inger-Marie; Johannessen, Gunnar; Skaane, Per; Roth Hoff, Solveig; Hofvind, Solveig

    2010-01-01

    Background: Studies comparing analog and digital mammography in breast cancer screening have shown conflicting results. Little is known about the use of digital photon-counting detectors. Purpose: To retrospectively compare performance indicators in screen-film (SFM) and full-field digital mammography (FFDM) using a photon-counting detector in a population-based screening program. Material and Methods: The Norwegian Social Science Data Services approved the study, which was part of the Norwegian Breast Cancer Screening Program. The program invites women aged 50-69 years to two-view mammography biannually. The study period was January 2005 to June 2006 for SFM and August 2006 to December 2007 for FFDM. Independent double reading was performed using a five-point rating scale for probability of cancer. Recalls due to abnormal mammography were retrospectively reviewed by an expert panel. Performance indicators for the two techniques were compared. Attendance rate was 83.6% (7442/8901) for SFM and 82.0% (6932/8451) for FFDM. Results: The recall rate due to abnormal mammography, cancer detection rate and positive predictive value did not differ significantly between SFM and FFDM: recall 2.3% (174/7442) versus 2.4% (168/6932), cancer detection 0.39% (29/7442) versus 0.48% (33/6932), positive predictive value 16.7% (29/174) versus 19.6% (33/168), respectively (P>0.05 for all). The recall rate due to technically inadequate mammograms was 0.3% (19/7442) for SFM and 0.01% (1/6932) for FFDM. In the retrospective review, a significantly higher proportion of calcifications and asymmetric density were categorized as normal or definitively benign in FFDM compared with SFM. The average glandular dose was 2.17 mGy for SFM and 1.25 mGy for FFDM. Conclusion: Performance indicators show that FFDM using photon-counting detector is suitable for breast cancer screening. The lower radiation dose and lower recalls due to technically inadequate mammograms are of importance in mammography

  11. The mammography screening employee inreach program.

    Science.gov (United States)

    Robinson, Joanne; Seltzer, Vicki; Lawrence, Loretta; Autz, George; Kostroff, Karen; Weiselberg, Lora; Colagiacomo, Maria

    2007-02-01

    To determine whether our health care employees were undergoing mammography screening according to American Cancer Society guidelines and to determine whether aggressive outreach, education and streamlining of mammography scheduling could improve compliance. All female employees at North Shore University Hospital (NSUH) and several other health system facilities (SF) were sent mailings to their homes that included breast health education and mammography screening guidelines, a questionnaire regarding their own mammography screening history and the opportunity to have their mammography screening scheduled by the Mammography Screening Employee Inreach Program (MSEIP) coordinator. Of the approximately 2,700 female employees aged 40 and over at NSUH and SF, 2,235 (82.7%) responded to the questionnaire, and 1,455 had a mammogram done via the MSEIP. Of the 1,455, 43% either were overdue for a mammogram or had never had one. During a second year of the MSEIP at NSUH and SF, an additional 1,706 mammograms were done. People employed in health care jobs do not necessarily avail themselves of appropriate health care screening. An aggressive program that utilized education, outreach and assistance with scheduling was effective in increasing compliance with mammography screening.

  12. Mammography: Technique and diagnostic accuracy

    International Nuclear Information System (INIS)

    Kim, Chung Ja; Bahk, Yong Whee; Lee, Don Young

    1974-01-01

    Mammography is now in world wide use, But this has received rather scanty attention in Korea. The purposes of the present communication are twofold: (1) Detailing of technical and photographic aspects of mam in ography and (2) an assessment of its diagnostic accuracy as experienced by us. The clinical materials consisted of 88 cases of mammography performed at the Department of Radiology, St. Mary's Hospital, Catholic Medical College during the 2 years-period from April 1972. We used nonscreen type mammographic or industrial fine- grain films, and a special mammographic device that can be attached to any of the ordinary radiographic machine. Technical factors are shown in Table II. Of 88 cases 19 were operated on or biopsied. There were 7 cases of carcinoma. 8 cases of inflammatory diseases, and 4 cases of benign tumor. Mammographic diagnosis was correct in 85.7% of carcinoma and 87.5% of inflammatory diseases. One misdiagnosis of 7 cases of carcinoma was turned out to be cystosarcoma phylloides. Of 4 cases of benign tumors 2 were correctly diagnosed, and the other 2 mistaken for either inflammatory disease or simple lactating breast. However, none of the benign conditions were diagnosed as malignant process. We found that nonscreen type mammographic or industrial fine-grain films, and hand-processing were necessary in obtaining the mammograms of desirable quality

  13. Mammography image compression using Wavelet

    International Nuclear Information System (INIS)

    Azuhar Ripin; Md Saion Salikin; Wan Hazlinda Ismail; Asmaliza Hashim; Norriza Md Isa

    2004-01-01

    Image compression plays an important role in many applications like medical imaging, televideo conferencing, remote sensing, document and facsimile transmission, which depend on the efficient manipulation, storage, and transmission of binary, gray scale, or color images. In Medical imaging application such Picture Archiving and Communication System (PACs), the image size or image stream size is too large and requires a large amount of storage space or high bandwidth for communication. Image compression techniques are divided into two categories namely lossy and lossless data compression. Wavelet method used in this project is a lossless compression method. In this method, the exact original mammography image data can be recovered. In this project, mammography images are digitized by using Vider Sierra Plus digitizer. The digitized images are compressed by using this wavelet image compression technique. Interactive Data Language (IDLs) numerical and visualization software is used to perform all of the calculations, to generate and display all of the compressed images. Results of this project are presented in this paper. (Author)

  14. Study on patient exposure from mammography, 3

    International Nuclear Information System (INIS)

    Sato, Miyao

    1983-01-01

    Risks and benefits of the patient from mammography performed in Japan were estimated, and the indication of mammography were discussed. 1) Breast cancers induced by mammography were estimated based on the average breast dose, the average life span, risks of radiation-induced breast cancer and the breast cancer significant factor. 2) The breast cancer significant factor was calculated, similar to those of leukemia significant factor by Hashizume, from latent periods of radiation-induced breast cancer and the excess breast cancer induction rate in female A-bomb survivors. 3) Numbers of the deaths and Lost-years were calculated from risks of radiation-induced breast cancer, incidence of breast cancer by mammography, cure rate of breast cancer, average life span and latent period of radiation-induced breast cancer. 4) Numbers of the increased life and years saved were calculated from the improved rate of the ability of diagnosis, frequency of mammography, the average life span and cure rate of breast cancer. 5) Induction of leukemia, lung cancer and thyroid cancer by mammography also were investigated. Its contribution was not significant, compared to the induction of breast cancer. 6) Comparing risk and benefit, the latter was much higher than the former by factors of 71-76. This was suggested the efficacy of mammography. 7) From a pointview of risk and benefit, routine mammography is contraindicative for 10-19 years old women because of large risk, the indication must be scrutinized for 20-29 years old ones, and the benefit increases with age for over 30 years old ones so that mammography was positively admitted for the symptomatic women. (author)

  15. Comparative study of dose estimation in the change a conventional mammography to digital mammography

    International Nuclear Information System (INIS)

    Vazquez Vazquez, R.; Otero Martinez, C.; Soto Bua, M.; Santamarina Vazquez, F.; Carril Iglesias, S.; Lobato Busto, R.; Luna Vega, V.; Mosquera Sueiro, J.; Sqanchez Garcia, M.; Pombar Camean, M.

    2011-01-01

    Mammographic studies are now one of the most demanding radiological because of its effectiveness in detecting breast cancer early. The introduction of digital mammography has been a major advance because it has overcome some of the limitations of conventional systems. Due to the nature of the radiosensitive glandular tissue becomes very important control of the dose given to patients. In the present study is to analyze the variations in dosimetry that can exist between a conventional mammography and digital mammography.

  16. Radiogenic breast cancer risk and mammography

    International Nuclear Information System (INIS)

    Jayaprakash, Shobha; Nair, C.P.R.; Rao, B.S.; Sawant, S.G.

    2001-01-01

    There is a general concern that the risks from mammography screening in inducting radiogenic breast cancer may outweigh the possible benefits to be derived from it. A review of epidemiological, case-control and cohort studies of radiogenic breast cancer, age-specific incidence and dose and dose-rate relationship reveals that such a fear is unfounded. The dose to the breast tissues in a quality assured mammography screening programme falls far below the levels that were observed to produce increased relative risk. The age-specific incidence rates also indicate that the need for mammography is for the women of age at which the relative risk is minimum

  17. Joint two-view information for computerized detection of microcalcifications on mammograms

    International Nuclear Information System (INIS)

    Sahiner, Berkman; Chan, H.-P.; Hadjiiski, Lubomir M.; Helvie, Mark A.; Paramagul, Chinatana; Ge Jun; Wei Jun; Zhou Chuan

    2006-01-01

    We are developing new techniques to improve the accuracy of computerized microcalcification detection by using the joint two-view information on craniocaudal (CC) and mediolateral-oblique (MLO) views. After cluster candidates were detected using a single-view detection technique, candidates on CC and MLO views were paired using their radial distances from the nipple. Candidate pairs were classified with a similarity classifier that used the joint information from both views. Each cluster candidate was also characterized by its single-view features. The outputs of the similarity classifier and the single-view classifier were fused and the cluster candidate was classified as a true microcalcification cluster or a false-positive (FP) using the fused two-view information. A data set of 116 pairs of mammograms containing microcalcification clusters and 203 pairs of normal images from the University of South Florida (USF) public database was used for training the two-view detection algorithm. The trained method was tested on an independent test set of 167 pairs of mammograms, which contained 71 normal pairs and 96 pairs with microcalcification clusters collected at the University of Michigan (UM). The similarity classifier had a very low FP rate for the test set at low and medium levels of sensitivity. However, the highest mammogram-based sensitivity that could be reached by the similarity classifier was 69%. The single-view classifier had a higher FP rate compared to the similarity classifier, but it could reach a maximum mammogram-based sensitivity of 93%. The fusion method combined the scores of these two classifiers so that the number of FPs was substantially reduced at relatively low and medium sensitivities, and a relatively high maximum sensitivity was maintained. For the malignant microcalcification clusters, at a mammogram-based sensitivity of 80%, the FP rates were 0.18 and 0.35 with the two-view fusion and single-view detection methods, respectively. When the

  18. Combined assessment (aspiration cytology and mammography) of ...

    African Journals Online (AJOL)

    Combined assessment (aspiration cytology and mammography) of clinically suspicious breast masses. W.F. van Wyk, D Dent, E Anne Hacking, Genevieve Learmonth, R.E. Kottler, C Anne Gudgeon, A Tiltman ...

  19. Mammography: What You Need to Know

    Science.gov (United States)

    ... While standing in front of the machine, a technologist will position your breast on a small platform. ... mammography or additional 3D imaging methods, such as ultrasound or MRI, are options for you. Ochs adds: “ ...

  20. Heavy-ion mammography and breast cancer

    International Nuclear Information System (INIS)

    Fabrikant, J.I.; Tobias, C.A.; Capp, M.P.; Holley, W.R.; Woodruff, K.H.; Sickles, E.A.

    1980-01-01

    Heavy-ion radiography is a new diagnostic imaging technique developed in our laboratory that produces superior density resolution at low radiation doses. Heavy-ion mammography has now emerged as a low-dose, safe, reliable, noninvasive diagnostic radiological procedure that can quantitate and image very small differences in soft tissue densities in the breast tissues of patients with clinical breast disease. The improved density resolution of heavy-ion mammography over conventional X-ray mammography and breast xerography provides the potential of detecting small breast cancers of less than 1 cm diameter. The radiation dose to the breast from carbon-ion mammorgraphy is about 50 mrad or less, and can potentially be only a fraction of this level. The results of the present clinical trial in progress of heavy-ion mammography in 37 patients, thus far studied, are extremely encouraging, and warrant continued study for application to the early diagnosis of breast cancer in women

  1. CONTRAST ENHANCED SPECTRAL MAMMOGRAPHY (CESM (REVIEW

    Directory of Open Access Journals (Sweden)

    N. I. Rozhkova

    2015-01-01

    Full Text Available The problem of early diagnosis of a breast cancer is extremely actual. Growth of incidence at women from 19 to 39 years increased for 34% over the last 10 years. It defines need of acceleration of development and deployment of the latest technologies of identification of the earliest symptoms of diseases. The x-ray mammography is the conducting method among of all radiological methods of diagnostics. Nevertheless a number of restrictions of method reduces its efficiency. The technologies increasing informational content of x-ray mammography – the leading method of screening – due to use of artificial contrasting and advantages of digital technologies are constantly developed. In this review it is described works, in which the authors having clinical experience of application of CESM – contrastenhanced spectral mammography on representative group of women. Positive sides and restrictions of new technology in comparison with mammography, ultrasonography and MRT are shown in this article.

  2. Mammography screening services: market segments and messages.

    Science.gov (United States)

    Scammon, D L; Smith, J A; Beard, T

    1991-01-01

    Mammography has become a vital tool for the early detection of breast cancer. Although many organizations and health care facilities are working to educate and motivate women to take advantage of the life saving opportunity that is offered through screening mammography, only twenty percent of women who should be screened actually have the procedure performed. In order to reach women who have not been screened, it is important to learn which factors most strongly motivate those women who do choose to have a mammogram. Depth interviews with 18 women attending a mobile mammography unit were conducted to explore the decision making process of women obtaining mammography screening services and to develop a profile of prevalent emotions, attitudes, and feelings associated with receiving breast cancer screening services. Analysis of the interview transcripts revealed several important themes to which health care professionals can direct marketing and health promotion strategies.

  3. Frequently Asked Questions about Digital Mammography

    Science.gov (United States)

    ... at www.fda.gov/findmammography . Do private insurance companies, Medicare and Medicaid pay for digital mammography exams, ... Map Nondiscrimination Website Policies U.S. Food and Drug Administration 10903 New Hampshire Avenue Silver Spring, MD 20993 ...

  4. Mammography and breast sonography in transsexual women

    Energy Technology Data Exchange (ETDEWEB)

    Weyers, S., E-mail: steven.weyers@ugent.b [Department of Gynecology, Ghent University Hospital, De Pintelaan 185, B-9000 Ghent (Belgium); Villeirs, G.; Vanherreweghe, E. [Department of Radiology, Ghent University Hospital, Ghent (Belgium); Verstraelen, H. [Department of Gynecology, Ghent University Hospital, De Pintelaan 185, B-9000 Ghent (Belgium); Monstrey, S. [Department of Plastic Surgery, Ghent University Hospital, Ghent (Belgium); Van den Broecke, R.; Gerris, J. [Department of Gynecology, Ghent University Hospital, De Pintelaan 185, B-9000 Ghent (Belgium)

    2010-06-15

    Data on the necessity of performing screening mammographies in transsexual women are lacking. The main objective of this study was to assess the possibility to perform mammography and breast sonography in transsexual women. Fifty Dutch-speaking transsexual women were interviewed about the following: attitude towards mammography and breast sonography, importance attributed to and satisfaction with breast appearance, opinion about the necessity of breast check-up, expectations regarding discomfort during the exams and knowledge about the breast surgery. A fasting blood sample, clinical breast exam, mammography and breast sonography were performed. At mammography the following parameters were noted: density, technical quality, location of the prostheses, presence of any abnormalities and painfulness. At sonography the following parameters were recorded: density, presence of cysts, visualisation of retro-areolar ducts or any abnormalities. Twenty-three percent of patients are not aware of the type of breast implants and 79% do not know their position to the pectoral muscles. Patient satisfaction with the appearance of their breasts was rather high (7.94 on a scale of 0-10). Mean expected and experienced pain from mammography was low (4.37 and 2.00 respectively). There was no statistically significant difference in expected pain between those who already had mammography and those who did not. There was a significant positive correlation between the expected and the experienced pain. Mammography and breast sonography were technically feasible and no gross anomalies were detected. Since both exams were judged as nearly painless, 98% of transsexual women intended to come back if they would be invited. Since breast cancer risk in transsexual women is largely unknown and breast exams are very well accepted, breast screening habits in this population should not differ from those of biological women.

  5. The Future of Contrast-Enhanced Mammography.

    Science.gov (United States)

    Covington, Matthew F; Pizzitola, Victor J; Lorans, Roxanne; Pockaj, Barbara A; Northfelt, Donald W; Appleton, Catherine M; Patel, Bhavika K

    2018-02-01

    The purpose of this article is to discuss facilitators of and barriers to future implementation of contrast-enhanced mammography (CEM) in the United States. CEM provides low-energy 2D mammographic images analogous to digital mammography and contrast-enhanced recombined images that allow assessment of neovascularity similar to that offered by MRI. The utilization of CEM in the United States is currently low but could increase rapidly given the many potential indications for its clinical use.

  6. Mammography and breast sonography in transsexual women

    International Nuclear Information System (INIS)

    Weyers, S.; Villeirs, G.; Vanherreweghe, E.; Verstraelen, H.; Monstrey, S.; Van den Broecke, R.; Gerris, J.

    2010-01-01

    Data on the necessity of performing screening mammographies in transsexual women are lacking. The main objective of this study was to assess the possibility to perform mammography and breast sonography in transsexual women. Fifty Dutch-speaking transsexual women were interviewed about the following: attitude towards mammography and breast sonography, importance attributed to and satisfaction with breast appearance, opinion about the necessity of breast check-up, expectations regarding discomfort during the exams and knowledge about the breast surgery. A fasting blood sample, clinical breast exam, mammography and breast sonography were performed. At mammography the following parameters were noted: density, technical quality, location of the prostheses, presence of any abnormalities and painfulness. At sonography the following parameters were recorded: density, presence of cysts, visualisation of retro-areolar ducts or any abnormalities. Twenty-three percent of patients are not aware of the type of breast implants and 79% do not know their position to the pectoral muscles. Patient satisfaction with the appearance of their breasts was rather high (7.94 on a scale of 0-10). Mean expected and experienced pain from mammography was low (4.37 and 2.00 respectively). There was no statistically significant difference in expected pain between those who already had mammography and those who did not. There was a significant positive correlation between the expected and the experienced pain. Mammography and breast sonography were technically feasible and no gross anomalies were detected. Since both exams were judged as nearly painless, 98% of transsexual women intended to come back if they would be invited. Since breast cancer risk in transsexual women is largely unknown and breast exams are very well accepted, breast screening habits in this population should not differ from those of biological women.

  7. Motivators and barriers to mammography screening uptake by female health-care workers in primary health-care centres: a cross-sectional study.

    Science.gov (United States)

    Nazzal, Zaher; Sholi, Hisham; Sholi, Suha B; Sholi, Mohammad B; Lahaseh, Rawya

    2018-02-21

    Mammography screening is an effective tool for early detection and management of breast cancer. Female health-care workers' awareness of breast cancer screening is important because their beliefs and behaviours could influence other women. The aim of this study was to assess mammography screening uptake by female health-care workers at primary health-care centres and to identify the primary motivators and barriers that affect uptake. This cross-sectional study included all governmental primary health-care centres in the West Bank. Governorates were grouped into three regions as follows: north West Bank (Nablus, Jenin, Tulkarm, Tubas, Qalqiliya, and Salfit), middle West Bank (Jerusalem, Jericho, and Ramallah), and south West Bank (Hebron, and Bethlehem). The study population included all female health-care workers older than 40 years. Those who performed mammography for a suspected mass or other breast abnormalities were excluded. A self-administered questionnaire was used to collect data on demographic characteristics, knowledge about mammography screening, the extent and regularity of mammography screening, and motivators and barriers influencing their mammography screening uptake. The rate of mammography screening uptake was calculated. χ 2 test and t tests were used to assess screening motivators and barriers. The study was approved by the Institutional Review Board of the An-Najah National University. Participation was voluntary, and written consent was obtained from each participant. 299 female health-care workers completed a self-administered questionnaire. The mean age of the participants was 46 years (SD 4·7). 284 (95%) women had adequate knowledge about breast cancer and mammography screening, and 149 (50%) women reported having had at least one mammogram. 62 (21%) women had had regular scheduled mammograms. The most frequent reported motivators were the perceived benefit that early detection of breast cancer is important for its management (269 [90

  8. Computer assisted visualization of digital mammography images

    International Nuclear Information System (INIS)

    Funke, M.; Breiter, N.; Grabbe, E.; Netsch, T.; Biehl, M.; Peitgen, H.O.

    1999-01-01

    Purpose: In a clinical study, the feasibility of using a mammography workstation for the display and interpretation of digital mammography images was evaluated and the results were compared with the corresponding laser film hard copies. Materials and Methods: Digital phosphorous plate radiographs of the entire breast were obtained in 30 patients using a direct magnification mammography system. The images were displayed for interpretation on the computer monitor of a dedicated mammography workstation and also presented as laser film hard copies on a film view box for comparison. The images were evaluted with respect to the image handling, the image quality and the visualization of relevant structures by 3 readers. Results: Handling and contrast of the monitor displayed images were found to be superior compared with the film hard copies. Image noise was found in some cases but did not compromise the interpretation of the monitor images. The visualization of relevant structures was equal with both modalities. Altogether, image interpretation with the mammography workstation was considered to be easy, quick and confident. Conclusions: Computer-assisted visualization and interpretation of digital mammography images using a dedicated workstation can be performed with sufficiently high diagnostic accuracy. (orig.) [de

  9. Screening mammography in Finland--1.5 million examinations with 97 percent specificity

    International Nuclear Information System (INIS)

    Dean, P.B.; Pamilo, M.

    1999-01-01

    A nationwide mammography screening program including women aged 50-59 years at the time of the first invitation and involving more than 100 radiologists was started in Finland in January, 1987. From 1987 through 1997, a total of 1,690,496 invitations to biennial two-view mammography screening was sent out. The compliance for screening was 88.5% with 1,495,744 screening examinations performed during this 11-year period. There were 49,020 recalls for further work-up studies and 9,689 women were referred for surgery. The total number of screening-detected breast cancers was 5,595, giving a detection rate of 3.7 cancers per 1000 screening studies. More than half of all surgical biopsies revealed breast cancer and 67.8% of the invasive cancers were at Stage I. The positive predictive value of referral to surgical biopsy increased from 33.2% in 1987 to 65.5% in 1997. and the ratio of malignant to benign biopsies more than tripled from the first to the fifth year of screening. The observed/expected ratio of invasive cancer detection was 2.44. Only 0.27% of all screening mammograms were followed by a benign biopsy, and 2.90% of all screening mammograms were followed by the women being recalled for further studies and not found to have breast cancer. This gave a specificity of recall after screening mammography greater than 97.0% and a specificity of referral to surgical biopsy greater than 99.7%. Measures of specificity improved considerably during the first three years of the screening program. The high specificity of screening mammography can be attributed to the nature of the screening process as well as to the opportunity for individual radiologists to attain a greater level of experience and competence. The decision to recall appears to have been crucial in determining the specificity

  10. Mammography

    Science.gov (United States)

    ... to those found in digital cameras and their efficiency enables better pictures with a lower radiation dose. ... greater accuracy in pinpointing the size, shape and location of breast abnormalities fewer unnecessary biopsies or additional ...

  11. Mammography

    International Nuclear Information System (INIS)

    Oliveira, S.B.

    1988-01-01

    The mamma anatomy are showed with the main characteristics for the mamography examination. The energy band, the additional filtration, the half-value thickness are also mentioned. The evaluation in the exposure and the doses in the mamography examination are described with a quality control for obtention the best image. (C.G.C.) [pt

  12. Family/Friend Recommendations and Mammography Intentions: The Roles of Perceived Mammography Norms and Support

    Science.gov (United States)

    Molina, Yamile; Ornelas, India J.; Doty, Sarah L.; Bishop, Sonia; Beresford, Shirley A. A.; Coronado, Gloria D.

    2015-01-01

    Identifying factors that increase mammography use among Latinas is an important public health priority. Latinas are more likely to report mammography intentions and use, if a family member or friend recommends that they get a mammogram. Little is known about the mechanisms underlying the relationship between social interactions and mammography…

  13. Tomosynthesis and contrast-enhanced digital mammography: recent advances in digital mammography

    International Nuclear Information System (INIS)

    Diekmann, Felix; Bick, Ulrich

    2007-01-01

    Digital mammography is more and more replacing conventional mammography. Initial concerns about an inferior image quality of digital mammography have been largely overcome and recent studies even show digital mammography to be superior in women with dense breasts, while at the same time reducing radiation exposure. Nevertheless, an important limitation of digital mammography remains: namely, the fact that summation may obscure lesions in dense breast tissue. However, digital mammography offers the option of so-called advanced applications, and two of these, contrast-enhanced mammography and tomosynthesis, are promising candidates for improving the detection of breast lesions otherwise obscured by the summation of dense tissue. Two techniques of contrast-enhanced mammography are available: temporal subtraction of images acquired before and after contrast administration and the so-called dual-energy technique, which means that pairs of low/high-energy images acquired after contrast administration are subtracted. Tomosynthesis on the other hand provides three-dimensional information on the breast. The images are acquired with different angulations of the X-ray tube while the object or detector is static. Various reconstruction algorithms can then be applied to the set of typically nine to 28 source images to reconstruct 1-mm slices with a reduced risk of obscuring pathology. Combinations of both advanced applications have only been investigated in individual experimental studies; more advanced software algorithms and CAD systems are still in their infancy and have only undergone preliminary clinical evaluation. (orig.)

  14. Characterization of microcalcification: can digital monitor zooming replace magnification mammography in full-field digital mammography?

    International Nuclear Information System (INIS)

    Kim, Min Jung; Kim, Eun-Kyung; Kwak, Jin Young; Son, Eun Ju; Youk, Ji Hyun; Choi, Seon Hyeong; Oh, Ki Keun; Han, Mooyoung

    2009-01-01

    The aim of this study was to compare the diagnostic accuracy and image quality of microcalcifications in zoomed digital contact mammography with digital magnification mammography. Three radiologists with different levels of experience in mammography reviewed 120 microcalcification clusters in 111 patients with a full-field digital mammography system relying on digital magnification mammogram (MAG) images and zoomed images from contact mammography (ZOOM) using commercially available zooming systems on monitors. Each radiologist estimated the probability of malignancy and rated the image quality and confidence rate. Performance was evaluated by sensitivity, specificity, positive predictive value, negative predictive value, and receiver operating characteristic (ROC) analysis. All three radiologists rated MAG images higher than ZOOM images for sensitivity with statistical significance (average value, 92% vs. 87%, P<0.05) and performance by ROC analysis improved with MAG imaging. The confidence rate for diagnosis decision and the assessment of lesion characteristics were also better in MAG images than in ZOOM images with statistical significance (P<0.0001). Digital magnification mammography can enhance diagnostic performance when characterizing microcalcifications. Images zoomed from digital contact mammography cannot serve as an alternative to direct magnification digital mammography. (orig.)

  15. Activity quantification of phantom using dual-head SPECT with two-view planar image

    International Nuclear Information System (INIS)

    Guo Leiming; Chen Tao; Sun Xiaoguang; Huang Gang

    2005-01-01

    The absorbed radiation dose from internally deposited radionuclide is a major factor in assessing risk and therapeutic utility in nuclear medicine diagnosis or treatment. The quantification of absolute activity in vivo is necessary procedure of estimating the absorbed dose of organ or tissue. To understand accuracy in the determination of organ activity, the experiments on 99 Tc m activity quantification were made for a body phantom using dual-heat SPECT with the two-view counting technique. Accuracy in the activity quantification is credible and is not affected by depth of source organ in vivo. When diameter of the radiation source is ≤2 cm, the most accurate activity quantification result can be obtained on the basis of establishing the system calibration factor and transmission factor. The use of Buijs's method is preferable, especially at very low source-to-background activity concentration rations. (authors)

  16. Organization and standards of screening and diagnostic mammography

    International Nuclear Information System (INIS)

    Linderbraten, L.D.; Chikirdin, Eh.G.; Rozhkova, N.I.

    1999-01-01

    Problem of organizing and standards of the reference and diagnostic mammography in our country is discussed. Attention is paid to the terminology, accreditation of mammographic establishments and specialists, specifications of equipment, image quality, mammography results processing, radiation doses [ru

  17. Distance-regular graphs

    NARCIS (Netherlands)

    van Dam, Edwin R.; Koolen, Jack H.; Tanaka, Hajime

    2016-01-01

    This is a survey of distance-regular graphs. We present an introduction to distance-regular graphs for the reader who is unfamiliar with the subject, and then give an overview of some developments in the area of distance-regular graphs since the monograph 'BCN'[Brouwer, A.E., Cohen, A.M., Neumaier,

  18. LL-regular grammars

    NARCIS (Netherlands)

    Nijholt, Antinus

    1980-01-01

    Culik II and Cogen introduced the class of LR-regular grammars, an extension of the LR(k) grammars. In this paper we consider an analogous extension of the LL(k) grammars called the LL-regular grammars. The relation of this class of grammars to other classes of grammars will be shown. Any LL-regular

  19. Data on the cost-benefit analysis of mammography

    International Nuclear Information System (INIS)

    Zarand, P.; Pentek, Z.

    1982-01-01

    The radiation exposure and the cost per examination are compared in the case of three methods: non-screen film mammography, 10-dose mammography and xeromammography. 10-dose mammography results in the lowest radiation exposure whereas xeromammography has the lowest cost. (L.E.)

  20. Baseline Screening Mammography: Performance of Full-Field Digital Mammography Versus Digital Breast Tomosynthesis.

    Science.gov (United States)

    McDonald, Elizabeth S; McCarthy, Anne Marie; Akhtar, Amana L; Synnestvedt, Marie B; Schnall, Mitchell; Conant, Emily F

    2015-11-01

    Baseline mammography studies have significantly higher recall rates than mammography studies with available comparison examinations. Digital breast tomosynthesis reduces recalls when compared with digital mammographic screening alone, but many sites operate in a hybrid environment. To maximize the effect of screening digital breast tomosynthesis with limited resources, choosing which patient populations will benefit most is critical. This study evaluates digital breast tomosynthesis in the baseline screening population. Outcomes were compared for 10,728 women who underwent digital mammography screening, including 1204 (11.2%) baseline studies, and 15,571 women who underwent digital breast tomosynthesis screening, including 1859 (11.9%) baseline studies. Recall rates, cancer detection rates, and positive predictive values were calculated. Logistic regression estimated the odds ratios of recall for digital mammography versus digital breast tomosynthesis for patients undergoing baseline screening and previously screened patients, adjusted for age, race, and breast density. In the baseline subgroup, recall rates for digital mammography and digital breast tomosynthesis screening were 20.5% and 16.0%, respectively (p = 0.002); digital breast tomosynthesis screening in the baseline subgroup resulted in a 22% reduction in recall compared with digital mammography, or 45 fewer patients recalled per 1000 patients screened. Digital breast tomosynthesis screening in the previously screened patients resulted in recall reduction of 14.3% (p tomosynthesis than from digital mammography alone.

  1. Doses in mammography. Preliminary study

    International Nuclear Information System (INIS)

    Marquez P, F.; Acosta R, N.; Universidad Nacional Mayor de San Marcos, Lima; Benavente, T.; Universidad Nacional Mayor de San Marcos, Lima; Poma, M.

    2002-01-01

    Mammography is the most important method to detect lesions in the breast with this technique one can detect small tumours before clear clinical symptoms appear. Mammographic image of require high quality standards due that the extremely low contrast between the normal and pathological areas in the breast, eg.g., they have similar attenuation and absorption coefficient. The x-ray mammographic systems, used in this study are Senographe 500t and Senographe DMR, a detector with a RadCal ionization chambers calibrated to the qualities of mammographic x-ray beams, and a breast simulator that is a phantoms of polymethylmethacrylate (PMMA) of several thicknesses with the equivalence of 50% of the glandular tissue. The results obtained indicate that the values of doses at the entrance surface of a breast (DES) are greater the reference value 20 mGy to 5,0 cm of PMMA and the values of the mean glandular dose (MGD) exceed the reference value of 2,1 mGy for 5,1 cm of compressed thick breast. We consider that the values high of the EDS and MGD are due that the x-ray systems no meeting in good condition or for used of x-ray spectra no suitable, so is recommendable be carried out test of quality control to the x-ray systems and also realize studies, or characterize the of x-ray mammographic spectra

  2. Regular Expression Pocket Reference

    CERN Document Server

    Stubblebine, Tony

    2007-01-01

    This handy little book offers programmers a complete overview of the syntax and semantics of regular expressions that are at the heart of every text-processing application. Ideal as a quick reference, Regular Expression Pocket Reference covers the regular expression APIs for Perl 5.8, Ruby (including some upcoming 1.9 features), Java, PHP, .NET and C#, Python, vi, JavaScript, and the PCRE regular expression libraries. This concise and easy-to-use reference puts a very powerful tool for manipulating text and data right at your fingertips. Composed of a mixture of symbols and text, regular exp

  3. Comparison of tomosynthesis plus digital mammography and digital mammography alone for breast cancer screening.

    Science.gov (United States)

    Haas, Brian M; Kalra, Vivek; Geisel, Jaime; Raghu, Madhavi; Durand, Melissa; Philpotts, Liane E

    2013-12-01

    To compare screening recall rates and cancer detection rates of tomosynthesis plus conventional digital mammography to those of conventional digital mammography alone. All patients presenting for screening mammography between October 1, 2011, and September 30, 2012, at four clinical sites were reviewed in this HIPAA-compliant retrospective study, for which the institutional review board granted approval and waived the requirement for informed consent. Patients at sites with digital tomosynthesis were offered screening with digital mammography plus tomosynthesis. Patients at sites without tomosynthesis underwent conventional digital mammography. Recall rates were calculated and stratified according to breast density and patient age. Cancer detection rates were calculated and stratified according to the presence of a risk factor for breast cancer. The Fisher exact test was used to compare the two groups. Multivariate logistic regression was used to assess the effect of screening method, breast density, patient age, and cancer risk on the odds of recall from screening. A total of 13 158 patients presented for screening mammography; 6100 received tomosynthesis. The overall recall rate was 8.4% for patients in the tomosynthesis group and 12.0% for those in the conventional mammography group (P tomosynthesis reduced recall rates for all breast density and patient age groups, with significant differences (P tomosynthesis versus 5.2 per 1000 in patients receiving conventional mammography alone (P = .70). Patients undergoing tomosynthesis plus digital mammography had significantly lower screening recall rates. The greatest reductions were for those younger than 50 years and those with dense breasts. A nonsignificant 9.5% increase in cancer detection was observed in the tomosynthesis group. © RSNA, 2013.

  4. Analysis of mammography on breast fibroadenoma

    International Nuclear Information System (INIS)

    Fu Xiaomin; Han Benyi; Zhao Yae

    2009-01-01

    Objective: To study the imaging characteristics of breast fibroadenoma on mammograms. Methods: Mammography of 70 patients with breast fibroadenoma confirmed by pathology were analyzed retrospectively. All patients took breast X-ray of mediolateral oblique projection and craniocaudal projection before operation. Results: In 70 cases with fibroadenoma, mammography revealed 74 foci (36 left breast, 38 right breast) of 62 cases, and failed to reveal lesions in 8 cases. The shape of the lesions was round or round-like lesion in 60(31%). The border was well-defined in 46 masses, partly well-outlined in 14 and ill-defined in 4. 'Membranoid sign' can be seen in 40 cases. Conclusion: Typical X-ray findings of breast fibroadenoma is very important, mammography is a good method of choice in diagnosis of fibroadenoma. (authors)

  5. Dual-energy contrast-enhanced mammography.

    Science.gov (United States)

    Travieso Aja, M M; Rodríguez Rodríguez, M; Alayón Hernández, S; Vega Benítez, V; Luzardo, O P

    2014-01-01

    The degree of vascularization in breast lesions is related to their malignancy. For this reason, functional diagnostic imaging techniques have become important in recent years. Dual-energy contrast-enhanced mammography is a new, apparently promising technique in breast cancer that provides information about the degree of vascularization of the lesion in addition to the morphological information provided by conventional mammography. This article describes the state of the art for dual-energy contrast-enhanced mammography. Based on 15 months' clinical experience, we illustrate this review with clinical cases that allow us to discuss the advantages and limitations of this technique. Copyright © 2014 SERAM. Published by Elsevier Espana. All rights reserved.

  6. Quality control tests for conventional mammography

    International Nuclear Information System (INIS)

    Dawod, Alnazer Ahmed Ibrahim

    2014-12-01

    Mammography is this the test that allows the radiologist to look at images of the inside of the breasts. Mammograms help detect breast cancer early successful treatment of breast cancer depends on that early diagnosis. Breast cancer is a very common condition. About one in every nine women develops breast cancer by the age of eighty. In addition to the clinical examination and self-examination, mammography plays important role in the detection of breast cancer before they become clinically visible tumors. The mammography is the most common test for early detection of breast cancer. Quality control techniques that done ensured importance of this programme to produce images with good diagnostic values and help radiologist to diagnose breast discase easily and avoid exposing patient to radiation hazards.(Author)

  7. Anxiety in mammography: mammographers' and clients' perspectives

    International Nuclear Information System (INIS)

    Galletta, S.; Joel, N.; Maguire, R.; Weaver, K.; Poulos, A.

    2003-01-01

    The aim of this study was to identify causes of anxiety experienced by mammographers and clients during mammography and strategies to decrease the anxiety generated by the mammographic procedure. Two questionnaires were distributed: one to mammographers in public and private centres within NSW, the other to women (clients) who have experienced mammography. Mammographers' and clients' rankings of causes of clients' anxiety demonstrated many similarities indicating the mammographers' acknowledgement of factors contributing to client anxiety. Thematic analysis provided important qualitative data concerning anxiety experienced by both mammographers and clients and the influence of mammographer and client behaviour on that anxiety. The results of this study have provided important new knowledge for mammographic practice and mammography education. By understanding the causes of anxiety experienced by clients, mammographers can provide an informed, empathetic approach to the mammographic process. By acknowledging factors which increase their own anxiety mammographers can reduce the impact of this on themselves and on their clients. Copyright (2003) Australian Institute of Radiography

  8. Simultaneous two-view epipolar geometry estimation and motion segmentation by 4D tensor voting.

    Science.gov (United States)

    Tong, Wai-Shun; Tang, Chi-Keung; Medioni, Gérard

    2004-09-01

    We address the problem of simultaneous two-view epipolar geometry estimation and motion segmentation from nonstatic scenes. Given a set of noisy image pairs containing matches of n objects, we propose an unconventional, efficient, and robust method, 4D tensor voting, for estimating the unknown n epipolar geometries, and segmenting the static and motion matching pairs into n independent motions. By considering the 4D isotropic and orthogonal joint image space, only two tensor voting passes are needed, and a very high noise to signal ratio (up to five) can be tolerated. Epipolar geometries corresponding to multiple, rigid motions are extracted in succession. Only two uncalibrated frames are needed, and no simplifying assumption (such as affine camera model or homographic model between images) other than the pin-hole camera model is made. Our novel approach consists of propagating a local geometric smoothness constraint in the 4D joint image space, followed by global consistency enforcement for extracting the fundamental matrices corresponding to independent motions. We have performed extensive experiments to compare our method with some representative algorithms to show that better performance on nonstatic scenes are achieved. Results on challenging data sets are presented.

  9. Audit of mammography performed in our hospital

    International Nuclear Information System (INIS)

    Kantharia, Surita

    2013-09-01

    A medical audit is a compilation of patient outcomes over a certain period of time. Audit of Mammography provides an objective criterion of the appropriateness and accuracy in image interpretation, and is the best measure of a mammographer's performance. The audit assesses 3 important outcomes: i) detection of the percentage of cancers in a population, ii) finding these cancers while they are still curable (small and node negative), iii) finding these cancers through an acceptably low number of recalls and biopsies. With this background, I am presenting an audit of Mammography done at our centre from the period May 2010 to April 2013. (author)

  10. A computerized expert system for mammography

    International Nuclear Information System (INIS)

    Jackson, V.P.; Dines, K.A.; Bassett, L.W.

    1988-01-01

    The authors have developed a computer-based expert system to aid in the interpretation of mammograms, breast sonograms, and clinical findings. The radiologist enters clinical and image data into the artificial intelligence system and receives a prediction of the etiology of lesions seen on breast imaging studies. This prototype interactive system has undergone preliminary clinical testing and evaluation. Ultimately, a more refined and complex system will be of value in mammography education, for general radiologists without ready access to mammography experts, for paramedical personnel, and for all mammographers in need of a breast imaging database and reporting systems

  11. Regularization by External Variables

    DEFF Research Database (Denmark)

    Bossolini, Elena; Edwards, R.; Glendinning, P. A.

    2016-01-01

    Regularization was a big topic at the 2016 CRM Intensive Research Program on Advances in Nonsmooth Dynamics. There are many open questions concerning well known kinds of regularization (e.g., by smoothing or hysteresis). Here, we propose a framework for an alternative and important kind of regula......Regularization was a big topic at the 2016 CRM Intensive Research Program on Advances in Nonsmooth Dynamics. There are many open questions concerning well known kinds of regularization (e.g., by smoothing or hysteresis). Here, we propose a framework for an alternative and important kind...

  12. Regular expressions cookbook

    CERN Document Server

    Goyvaerts, Jan

    2009-01-01

    This cookbook provides more than 100 recipes to help you crunch data and manipulate text with regular expressions. Every programmer can find uses for regular expressions, but their power doesn't come worry-free. Even seasoned users often suffer from poor performance, false positives, false negatives, or perplexing bugs. Regular Expressions Cookbook offers step-by-step instructions for some of the most common tasks involving this tool, with recipes for C#, Java, JavaScript, Perl, PHP, Python, Ruby, and VB.NET. With this book, you will: Understand the basics of regular expressions through a

  13. One more hurdle to increasing mammography screening: pubescent, adolescent, and prior mammography screening experiences.

    Science.gov (United States)

    Thomas, Eileen; Usher, LaToya

    2009-01-01

    Approximately $8.1 billion dollars is spent each year in the United States alone on the treatment of breast cancer. Survival rates are dependent on access to, and utilization of, early detection services. The primary reason for disparity in breast cancer mortality is the delay in time to diagnosis, resulting in poor prognosis. Despite ongoing research to understand barriers to mammography screening, recent studies report a decrease in mammography screening among all racial groups. A qualitative approach was used to elicit information from 36 White non- Hispanic, African-American, Hispanic, and Native American women without a history of breast cancer. Women were invited to share written or audiotape-recorded narratives about experiences pertaining to their breasts and their mammography screening experiences. Major categories identified were: teasing, family norms and values, media/societal influence, body image, and mammography screening experiences. The resulting effects of these experiences left these women with feelings of shame and "conflict" regarding their breasts. The major theme identified was breast conflict. Findings suggest that breast conflict may persist throughout the lifespan and can have a negative influence on a woman's decision to participate in mammography screening. The authors hypothesize that experiences that occur during adolescence pertaining to young girls' breasts can influence a women's body image, which in turn can later in life affect health-seeking behaviors related to mammography screening. These findings have implications for public health practice in planning for breast cancer screening, education, and interventions for women from diverse racial/ethnics groups.

  14. Dual-energy mammography: simulation studies

    International Nuclear Information System (INIS)

    Bliznakova, K; Kolitsi, Z; Pallikarakis, N

    2006-01-01

    This paper presents a mammography simulator and demonstrates its applicability in feasibility studies in dual-energy (DE) subtraction mammography. This mammography simulator is an evolution of a previously presented x-ray imaging simulation system, which has been extended with new functionalities that are specific for DE simulations. The new features include incident exposure and dose calculations, the implementation of a DE subtraction algorithm as well as amendments to the detector and source modelling. The system was then verified by simulating experiments and comparing their results against published data. The simulator was used to carry out a feasibility study of the applicability of DE techniques in mammography, and more precisely to examine whether this modality could result in better visualization and detection of microcalcifications. Investigations were carried out using a 3D breast software phantom of average thickness, monoenergetic and polyenergetic beam spectra and various detector configurations. Dual-shot techniques were simulated. Results showed the advantage of using monoenergetic in comparison with polyenergetic beams. Optimization studies with monochromatic sources were carried out to obtain the optimal low and high incident energies, based on the assessment of the figure of merit of the simulated microcalcifications in the subtracted images. The results of the simulation study with the optimal energies demonstrated that the use of the DE technique can improve visualization and increase detectability, allowing identification of microcalcifications of sizes as small as 200 μm. The quantitative results are also verified by means of a visual inspection of the synthetic images

  15. Mammography activity in Norway 1983 to 2008

    DEFF Research Database (Denmark)

    Lynge, Elsebeth; Braaten, Tonje; Njor, Sisse H

    2011-01-01

    In Norway, an organized screening mammography program, the Norwegian Breast Cancer Screening Program (NBCSP) started in four counties in 1996 and became nationwide in 2004. We collected data on pre-program screening activity, and in view of this activity we evaluated the potential impact...... of the program on breast cancer mortality in Norway....

  16. Computed Radiography Exposure Indices in Mammography | Koen ...

    African Journals Online (AJOL)

    Computed Radiography Exposure Indices in Mammography. L Koen, C Herbst, W Rae. Abstract. Background. Studies indicate that computed radiography (CR) can lead to increased radiation dose to patients. It is therefore important to relate the exposure indicators provided by CR manufacturers to the radiation dose ...

  17. Beyond the mammography debate: a moderate perspective.

    Science.gov (United States)

    Kaniklidis, C

    2015-06-01

    After some decades of contention, one can almost despair and conclude that (paraphrasing) "the mammography debate you will have with you always." Against that sentiment, in this review I argue, after reflecting on some of the major themes of this long-standing debate, that we must begin to move beyond the narrow borders of claim and counterclaim to seek consensus on what the balance of methodologically sound and critically appraised evidence demonstrates, and also to find overlooked underlying convergences; after acknowledging the reality of some residual and non-trivial harms from mammography, to promote effective strategies for harm mitigation; and to encourage deployment of new screening modalities that will render many of the issues and concerns in the debate obsolete. To these ends, I provide a sketch of what this looking forward and beyond the current debate might look like, leveraging advantages from abbreviated breast magnetic resonance imaging technologies (such as the ultrafast and twist protocols) and from digital breast tomosynthesis-also known as three-dimensional mammography. I also locate the debate within the broader context of mammography in the real world as it plays out not for the disputants, but for the stakeholders themselves: the screening-eligible patients and the physicians in the front lines who are charged with enabling both the acts of screening and the facts of screening at their maximally objective and patient-accessible levels to facilitate informed decisions.

  18. Mammography practices for radiation protection in Kenya

    International Nuclear Information System (INIS)

    Shadrack, Anthony K.

    2008-01-01

    All mammography units in the country, totaling fourteen in number at the time, were evaluated on the basis of performance and practice to come up with useful data for summing up the mammography practice in Kenya. The study was carried out by performing hands-on quality control tests on the units using internationally established protocols. Image quality and dose measurement data were generated in all the centers and clearly indicated that the practice of mammography, more so on optimization viewpoint is so much varied. A standard method was used to obtain these data by use of mammography accreditation phantom. Data from actual patients was also collected in three major centers in Nairobi. On the criteria used for evaluating phantom image quality, ten out of fourteen units did satisfy the set criterion. The average glandular dose was 2.79 mGy per cranio caudal (cc) view of the phantom and 3.27 mGy per cc view for the sampled patients. The internationally recommended dose level for such a view is 3.0 mGy. One worrying observation made was that most units failed on one of the easiest test of mammographic unit assembly. Of most concern was the lack of technique charts for the practice detailing the imaging parameters being employed for the procedure. Most centers do not take the servicing of equipment seriously and others merely ignore even the crucial issues of equipment performance like the automatic exposure control and viewing conditions of the reporting areas.The results of this study calls for the setting up of a programme of optimization of radiological protection in mammography using the experience of other countries that have put in place quality assurance programs, setting and adoption of Dose Reference Levels (DRLs) as part of Quality Assurance (QA). This practice needs an effective quality control program which should start with the selection of appropriate equipment for mammography and the use of qualified personnel including the radiologist, radiographer

  19. Regularities of Multifractal Measures

    Indian Academy of Sciences (India)

    First, we prove the decomposition theorem for the regularities of multifractal Hausdorff measure and packing measure in R R d . This decomposition theorem enables us to split a set into regular and irregular parts, so that we can analyze each separately, and recombine them without affecting density properties. Next, we ...

  20. Stochastic analytic regularization

    International Nuclear Information System (INIS)

    Alfaro, J.

    1984-07-01

    Stochastic regularization is reexamined, pointing out a restriction on its use due to a new type of divergence which is not present in the unregulated theory. Furthermore, we introduce a new form of stochastic regularization which permits the use of a minimal subtraction scheme to define the renormalized Green functions. (author)

  1. Analysis of medical exposures in digital mammography

    International Nuclear Information System (INIS)

    Oliveira, Sergio R.; Mantuano, Natalia O.; Albrecht, Afonso S.

    2014-01-01

    Currently, the use of digital mammography in the early diagnosis of breast cancer is increasingly common due to the production of high definition image that allows to detect subtle changes in breast images profiles. However it is necessary to be an improvement of the technique used since some devices offer minimization parameters of entrance dose to the skin. Thus, this study seeks to examine how the qualification of technical professionals in radiology interferes with the use of the techniques applied in mammography. For this, survey was carried out in a hospital in the city of Rio de Janeiro, which evaluated the scans of 1190 patients undergoing routine mammography (It is considered routinely the 4 basic exhibitions: with 2 flow skull and 2 medium oblique side, excluding repeats and supplements) in 2013. The medical exposures analyzed obtained from a single full digital equipment, model Senographe DS were compared with three different procedures performed by professionals in mammography techniques. The images were classified according to exposure techniques available in the equipment: Standard (STD), contrast (CNT) and dose (dose), and to be selected as breast density of the patient. Comparing the variation of the radiographic technique in relation to the professional who made the exhibition, what is observed is that the professional B presented the best conduct in relation to radiological protection, because she considered breast density in the choice of technical equipment parameter. The professional A, which is newly formed, and C, which has more service time, almost did not perform variations in the pattern of exposure, even for different breast densities. Thus, we can conclude that there is a need to update the professionals so that the tools available of dose limitation and mamas variability to digital mammography are efficiently employed in the service routine and thus meet the requirements of current legislation

  2. Computer-aided diagnosis in routine mammography

    International Nuclear Information System (INIS)

    Sittek, H.; Perlet, C.; Helmberger, R.; Linsmeier, E.; Kessler, M.; Reiser, M.

    1998-01-01

    Purpose: Computer-aided diagnosis in mammography is a topic many study groups have been concerned with since the first presentation of a system for computer-aided interpretation in 1967. Currently, there is only one system avilable for clinical use in mammography, the CAD-System Image Checker (R2 Technology). The purpose of our prospective study was to evaluate whether the integration of the CAD-system into the routine of a radiological breast diagnosis unit is feasible. Results: After the installation of the CAD-system, 300 patients with 1110 mammograms were included for evaluation in the present study. In 54 of these cases histological examination was indicated due to suspect criteria on conventional mammography. In 39 of 54 cases (72,2%) malignancy could be proven histologically. The CAD-system marked 82,1% of the histologically verified carcinomas correctly 94,3% of all 1797 marks made by the CAD-system indicated normal or benign structures. Routinely performed CAD analysis prolonged patients waiting time by about 15 min because the marks of the CAD system had to be interpreted in addition to the routine diagnostic investigations. Conclusion: Our experience with the use of the CAD-system in daily routine showed that CAD analysis can easily be integrated into a preexisting mammography unit. However, the diagnostic benefit is not yet clearly established. Since the rate of false negative marks by the CAD-system Image Checker is still high, the results of CAD analysis must be checked and corrected by an observer well experienced in mammography reading. (orig.) [de

  3. Radiology Residents' Performance in Screening Mammography Interpretation

    International Nuclear Information System (INIS)

    Lee, Eun Hye; Lyou, Chae Yeon

    2013-01-01

    To evaluate radiology residents' performance in screening mammography interpretation and to analyze the factors affecting performance. We enrolled 203 residents from 21 institutions and performed mammography interpretation tests. Between the trainee and non-trainee groups, we compared the interpretation score, recall rate, sensitivity, positive predictive value (PPV) and false-positive rate (FPR). We estimated the training effect using the score differences between trainee and non-trainee groups. We analyzed the factors affecting performance between training-effective and non-effective groups. Trainees were superior to non-trainees regarding interpretation score (43.1 vs. 37.1), recall rate (11.0 vs. 15.5%), sensitivity (83.6 vs. 72.0%), PPV (53.0 vs. 32.4%) and FPR (13.5 vs. 25.5). The longer the training period, the better were the interpretation score, recall rate, sensitivity, PPV and FPR (rho = 0.486, -0.375, 0.343, 0.504, -0.446, respectively). The training affected an increase by an average of 6 points; however, 31.6% of institutions showed no effect. A difference was noted in the volume of mammography interpretation during a month (594.0 vs. 476.9) and dedication of breast staff (61.5 vs. 0%) between training-effective and non-effective groups. Trainees showed better performance in mammography interpretation compared to non-trainees. Moreover, performance was correlated with the training period. The factors affecting performance were the volume of mammography interpretation and the dedication of the breast staff.

  4. Calibration procedures for mammography dosemeters in Poland

    International Nuclear Information System (INIS)

    Gwiazdowska, B.; Ulkowski, P.; Tolwinski, J.; Bulski, W.

    2002-01-01

    Breast cancer is the most frequent tumour in women and the effectiveness of the treatment depends dramatically on the early detection of the disease. That is the reason why in Poland the mammography control examinations are strongly supported by the Centre of Oncology. In Poland there are over 400 mammography units which account for about 300,000 examinations per year. An investigation performed by the Medical Physics Department of the Centre of Oncology in Warsaw at about 100 mammography facilities proved that in most cases the doses absorbed by the patients could be reduced without decrease of image quality. This is one of the reasons why the Polish Secondary Standard Dosimetry Laboratory (SSDL) dealing mainly with calibration of radiotherapy dosemeters is extending its activities and therefore new facilities and equipment adapted for calibration of mammographic dosemeters have been installed. The mammography dosimetry calibration equipment is permanently installed in the same laboratory room where the radiotherapy dosemeters are calibrated. A base of a mammography unit no longer in clinical use, together with its movable system has been adapted to handle ionization chamber holders. An X-ray tube with a 50 kV high frequency generator was also installed. The tube, a Varian type OEG-50-2, (designed for laboratory applications) with molybdenum anode of an anode angle 23,7 deg. and with a large focus, effective size approximately 5 mm 2 , has an inherent filtration of 0,25 mm beryllium. It is installed in a housing with 2mm lead shielding; a cone shaped beam is formed by a system of three collimators

  5. Thermoluminescence dosimetry in quality imaging in CR mammography systems

    Energy Technology Data Exchange (ETDEWEB)

    Gaona, E.; Franco E, J.G. [UAM-Xochimilco, 04960 Mexico D.F. (Mexico); Azorin N, J. [UAM-Iztapalapa, 09340 Mexico D.F. (Mexico); Diaz G, J.A.I. [CICATA, Unidad Legaria, Av. Legaria 694, 11599 mexico D.F. (Mexico); Arreola, M. [Department of Radiology, Shands Hospital at UF, PO Box 100374, Gainesville, FL 32610-0374 (United States)

    2006-07-01

    The aim of this work is to estimate the average glandular dose with Thermoluminescence Dosimetry (TLD) and comparison with quality imaging in CR mammography. For measuring dose, FDA and ACR use a phantom, so that dose and image quality are assessed with the same test object. The mammography is a radiological image to visualize early biological manifestations of breast cancer. Digital systems have two types of image-capturing devices, Full Field Digital Mammography (FFDM) and CR mammography. In Mexico, there are several CR mammography systems in clinical use, but only one CR mammography system has been approved for use by the FDA. Mammography CR uses a photostimulable phosphor detector (PSP) system. Most CR plates are made of 85% BaFBr and 15% BaFI doped with europium (Eu) commonly called barium fluoro halide. We carry out an exploratory survey of six CR mammography units from three different manufacturers and six dedicated x-ray mammography units with fully automatic exposure. The results show three CR mammography units (50%) have a dose that overcomes 3.0 mGy and it doesn't improve the image quality and dose to the breast will be excessive. The differences between doses averages from TLD system and dosimeter with ionization chamber are less than 10%. TLD system is a good option for average glandular dose measurement. (Author)

  6. Thermoluminescence dosimetry in quality imaging in CR mammography systems

    International Nuclear Information System (INIS)

    Gaona, E.; Franco E, J.G.; Azorin N, J.; Diaz G, J.A.I.; Arreola, M.

    2006-01-01

    The aim of this work is to estimate the average glandular dose with Thermoluminescence Dosimetry (TLD) and comparison with quality imaging in CR mammography. For measuring dose, FDA and ACR use a phantom, so that dose and image quality are assessed with the same test object. The mammography is a radiological image to visualize early biological manifestations of breast cancer. Digital systems have two types of image-capturing devices, Full Field Digital Mammography (FFDM) and CR mammography. In Mexico, there are several CR mammography systems in clinical use, but only one CR mammography system has been approved for use by the FDA. Mammography CR uses a photostimulable phosphor detector (PSP) system. Most CR plates are made of 85% BaFBr and 15% BaFI doped with europium (Eu) commonly called barium fluoro halide. We carry out an exploratory survey of six CR mammography units from three different manufacturers and six dedicated x-ray mammography units with fully automatic exposure. The results show three CR mammography units (50%) have a dose that overcomes 3.0 mGy and it doesn't improve the image quality and dose to the breast will be excessive. The differences between doses averages from TLD system and dosimeter with ionization chamber are less than 10%. TLD system is a good option for average glandular dose measurement. (Author)

  7. Patient dose in digital mammography

    International Nuclear Information System (INIS)

    Chevalier, Margarita; Moran, Pilar; Ten, Jose I.; Fernandez Soto, Jose M.; Cepeda, T.; Vano, Eliseo

    2004-01-01

    In the present investigation, we analyze the dose of 5034 patients (20 137 images) who underwent mammographic examinations with a full-field digital mammography system. Also, we evaluate the system calibration by analyzing the exposure factors as a function of breast thickness. The information relevant to this study has been extracted from the image DICOM header and stored in a database during a 3-year period (March 2001-October 2003). Patient data included age, breast thickness, kVp, mAs, target/filter combination, and nominal dose values. Entrance surface air kerma (ESAK) without backscatter was calculated from the tube output as measured for each voltage used under clinical conditions and from the tube loading (mAs) included in the DICOM header. Mean values for the patient age and compressed breast thickness were 56 years (SD: 11) and 52 mm (SD: 13), respectively. The majority of the images was acquired using the STD (for standard) automatic mode (98%). The most frequent target/filter combination automatically selected for breast smaller than 35 mm was Mo/Mo (75%); for intermediate thicknesses between 35 and 65 mm, the combinations were Mo/Rh (54%) and Rh/Rh (38.5%); Rh/Rh was the combination selected for 91% of the cases for breasts thicker than 65 mm. A wide kVp range was observed for each target/filter combination. The most frequent values were 28 kVp for Mo/Mo, 29 kVp for Mo/Rh, and 29 and 30 kV for Rh/Rh. Exposure times ranged from 0.2 to 4.2 s with a mean value of 1.1 s. Average glandular doses (AGD) per exposure were calculated by multiplying the ESAK values by the conversion factors tabulated by Dance for women in the age groups 50 to 64 and 40 to 49. This approach is based on the dependence of breast glandularity on breast thickness and age. The total mean average glandular dose (AGD T ) was calculated by summing the values associated with the pre-exposure and with the main exposure. Mean AGD T per exposure was 1.88 mGy (CI 0.01) and the mean AGD T per

  8. Mammography-oncogenecity at low doses

    International Nuclear Information System (INIS)

    Heyes, G J; Mill, A J; Charles, M W

    2009-01-01

    Controversy exists regarding the biological effectiveness of low energy x-rays used for mammography breast screening. Recent radiobiology studies have provided compelling evidence that these low energy x-rays may be 4.42 ± 2.02 times more effective in causing mutational damage than higher energy x-rays. These data include a study involving in vitro irradiation of a human cell line using a mammography x-ray source and a high energy source which matches the spectrum of radiation observed in survivors from the Hiroshima atomic bomb. Current radiation risk estimates rely heavily on data from the atomic bomb survivors, and a direct comparison between the diagnostic energies used in the UK breast screening programme and those used for risk estimates can now be made. Evidence highlighting the increase in relative biological effectiveness (RBE) of mammography x-rays to a range of x-ray energies implies that the risks of radiation-induced breast cancers for mammography x-rays are potentially underestimated by a factor of four. A pooled analysis of three measurements gives a maximal RBE (for malignant transformation of human cells in vitro) of 4.02 ± 0.72 for 29 kVp (peak accelerating voltage) x-rays compared to high energy electrons and higher energy x-rays. For the majority of women in the UK NHS breast screening programme, it is shown that the benefit safely exceeds the risk of possible cancer induction even when this higher biological effectiveness factor is applied. The risk/benefit analysis, however, implies the need for caution for women screened under the age of 50, and particularly for those with a family history (and therefore a likely genetic susceptibility) of breast cancer. In vitro radiobiological data are generally acquired at high doses, and there are different extrapolation mechanisms to the low doses seen clinically. Recent low dose in vitro data have indicated a potential suppressive effect at very low dose rates and doses. Whilst mammography is a low

  9. Sparse structure regularized ranking

    KAUST Repository

    Wang, Jim Jing-Yan; Sun, Yijun; Gao, Xin

    2014-01-01

    Learning ranking scores is critical for the multimedia database retrieval problem. In this paper, we propose a novel ranking score learning algorithm by exploring the sparse structure and using it to regularize ranking scores. To explore the sparse

  10. Regular expression containment

    DEFF Research Database (Denmark)

    Henglein, Fritz; Nielsen, Lasse

    2011-01-01

    We present a new sound and complete axiomatization of regular expression containment. It consists of the conventional axiomatiza- tion of concatenation, alternation, empty set and (the singleton set containing) the empty string as an idempotent semiring, the fixed- point rule E* = 1 + E × E......* for Kleene-star, and a general coin- duction rule as the only additional rule. Our axiomatization gives rise to a natural computational inter- pretation of regular expressions as simple types that represent parse trees, and of containment proofs as coercions. This gives the axiom- atization a Curry......-Howard-style constructive interpretation: Con- tainment proofs do not only certify a language-theoretic contain- ment, but, under our computational interpretation, constructively transform a membership proof of a string in one regular expres- sion into a membership proof of the same string in another regular expression. We...

  11. Supersymmetric dimensional regularization

    International Nuclear Information System (INIS)

    Siegel, W.; Townsend, P.K.; van Nieuwenhuizen, P.

    1980-01-01

    There is a simple modification of dimension regularization which preserves supersymmetry: dimensional reduction to real D < 4, followed by analytic continuation to complex D. In terms of component fields, this means fixing the ranges of all indices on the fields (and therefore the numbers of Fermi and Bose components). For superfields, it means continuing in the dimensionality of x-space while fixing the dimensionality of theta-space. This regularization procedure allows the simple manipulation of spinor derivatives in supergraph calculations. The resulting rules are: (1) First do all algebra exactly as in D = 4; (2) Then do the momentum integrals as in ordinary dimensional regularization. This regularization procedure needs extra rules before one can say that it is consistent. Such extra rules needed for superconformal anomalies are discussed. Problems associated with renormalizability and higher order loops are also discussed

  12. Regularized maximum correntropy machine

    KAUST Repository

    Wang, Jim Jing-Yan; Wang, Yunji; Jing, Bing-Yi; Gao, Xin

    2015-01-01

    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  13. Regularized maximum correntropy machine

    KAUST Repository

    Wang, Jim Jing-Yan

    2015-02-12

    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  14. Cost-effectiveness of increasing access to mammography through mobile mammography for older women.

    Science.gov (United States)

    Naeim, Arash; Keeler, Emmett; Bassett, Lawrence W; Parikh, Jay; Bastani, Roshan; Reuben, David B

    2009-02-01

    To compare the costs of mobile and stationary mammography and examine the incremental cost-effectiveness of using mobile mammography to increase screening rates. A cost-effectiveness analysis was performed using effectiveness data from a randomized clinical trial and modeling of costs associated with the mobile mammography intervention. The trial involved 60 community-based meal sites, senior centers, and clubs. Four hundred ninety-nine individuals were enrolled in the study, of whom 463 had outcome data available for analysis. Costs were calculated for stationary and mobile mammography, as well as costs due to differences in technology and film versus digital. Incremental cost-effectiveness (cost per additional screen) was modeled, and sensitivity analysis was performed by altering efficiency (throughput) and effectiveness based on subgroup data from the randomized trial. The estimated annual costs were $435,162 for a stationary unit, $539,052 for a mobile film unit, and $456, 392 for a mobile digital unit. Assuming mobile units are less efficient (50% annual volume), the cost per screen was $41 for a stationary unit, $86 for a mobile film unit, and $102 for a mobile digital unit. The incremental cost per additional screen were $207 for a mobile film unit and $264 for a mobile digital unit over a stationary unit. Although mobile mammography is a more effective way to screen older women, the absolute cost per screen of mobile units is higher, whereas the reimbursement is no different. Financial barriers may impede the widespread use of this approach.

  15. Radiation exposure of contrast-enhanced spectral mammography compared with full-field digital mammography.

    Science.gov (United States)

    Jeukens, Cécile R L P N; Lalji, Ulrich C; Meijer, Eduard; Bakija, Betina; Theunissen, Robin; Wildberger, Joachim E; Lobbes, Marc B I

    2014-10-01

    Contrast-enhanced spectral mammography (CESM) shows promising initial results but comes at the cost of increased dose as compared with full-field digital mammography (FFDM). We aimed to quantitatively assess the dose increase of CESM in comparison with FFDM. Radiation exposure-related data (such as kilovoltage, compressed breast thickness, glandularity, entrance skin air kerma (ESAK), and average glandular dose (AGD) were retrieved for 47 CESM and 715 FFDM patients. All examinations were performed on 1 mammography unit. Radiation dose values reported by the unit were validated by phantom measurements. Descriptive statistics of the patient data were generated using a statistical software package. Dose values reported by the mammography unit were in good qualitative agreement with those of phantom measurements. Mean ESAK was 10.5 mGy for a CESM exposure and 7.46 mGy for an FFDM exposure. Mean AGD for a CESM exposure was 2.80 mGy and 1.55 mGy for an FFDM exposure. Compared with our institutional FFDM, the AGD of a single CESM exposure is increased by 1.25 mGy (+81%), whereas ESAK is increased by 3.07 mGy (+41%). Dose values of both techniques meet the recommendations for maximum dose in mammography.

  16. Risks, radiation dose and image quality of mammography

    International Nuclear Information System (INIS)

    Menges, V.

    1979-01-01

    For some time to come, early detection of breast cancer will remain the only way to improve the therapeutical success. Mammography is an absolutely indispensible way to take advantage of this opportunity. Today, mammography is undoubtedly the most reliable method of examination for an early detection of breast cancer. Only mammography can detect carcinomas smaller than the critical tumour size of 1cm. If carried out properly and with present dose levels, it involves hardly any radiation risk. (orig.) [de

  17. Mammography Screening Among African-American Women with a Family History of Breast Cancer

    National Research Council Canada - National Science Library

    Lipkus, Issac

    1997-01-01

    Comparisons were made between African-American women with and without a family history of breast cancer with respect to mammography screening, attitudes towards mammography screening and perceptions...

  18. Image Quality and Patient Dose Optimisation in Mammography in Slovakia

    International Nuclear Information System (INIS)

    Horvathova, M.; Nikodemova, D.; Prikazska, M.

    2003-01-01

    Breast cancer represents also in Slovakia the greatest cancer risk for women, with great incidence and mortality. Conventional film-screen mammography is still the primary breast imaging modality with increasing number of mammography units and mammography examinations. From the radiation protection point of view achievement of good practice in mammography department by implementation of quality assurance play an important role for reduction of patients doses. Introduction of QA needs trained and experienced staff and requires close collaboration between radiologists, medical physicist and radiographers. At the beginning of nineties at the Institute of Preventive and Clinical Medicine we started with a survey of mean glandular doses at 15 existing mammography units in the country. On the basis of a questionnaire in the year 1991 were performed 10 488 mammography examinations, where due to out of date mammography units the mean glandular dose reached more as 3 mGy. In the following years the claim to the modern mammography units kept growing and in the year 1999 the total number of 63 mammography units were operating in Slovakia providing about 101 471 mammography examinations. According to the alarming increase of the number of mammography examinations it is absolutely necessary to work out criteria and principles for Quality Control at mammography workplaces in our country and make it obligatory for the staff of all mammography units. Summarising the CRP results it can be stated that they: 1) Initiated the suggestion of unified QA/QC criteria in mammography and the urgent need to implement them into the national program of radiology image quality improvement; 2) Remitted on unhomogenity not only in the equipment outfit but also in the procedure of evaluation of the measured parameters and imaging quality; 3) Revealed the shortcomings in the everyday practice of mammography units which can be removed only by comprehensive by training of personal in imaging radiology

  19. A comparison of digital mammography detectors and emerging technology

    International Nuclear Information System (INIS)

    Diffey, J.L.

    2015-01-01

    The overall diagnostic accuracy of digital mammography in the context of screening has been shown to be similar or slightly better than screen-film mammography. However, digital mammography encompasses both Computed Radiography (CR) and integrated Digital Radiography (DR) and there is increasing evidence to suggest that differences in detector technology are associated with variations in cancer detection rate, dose and image quality. These differences are examined in detail. Although digital mammography offers many advantages compared to screen-film, there are still some limitations with its use as a screening tool and reduced cancer detection in dense breasts remains an issue. Digital mammography detectors have paved the way for emerging technologies which may offer improvements. Taking the definition of mammography to only include X-ray imaging of the breast, this article focuses on tomosynthesis, contrast-enhanced digital mammography, stereoscopic mammography and dedicated breast computed tomography. Advanced software applications such as Computed Aided Detection (CAD) and quantitative breast density assessment are also presented. The benefits and limitations of each technique are discussed. - Highlights: • Digital detector technology affects cancer detection rate, dose and image quality. • Digital detectors have facilitated new technologies such as tomosynthesis. • 3-D techniques reduce superimposition and increase cancer detection in dense breasts. • Contrast-enhanced mammography demonstrates improved sensitivity and specificity.

  20. Investigation of actual conditions of mammography in Kagoshima prefecture

    International Nuclear Information System (INIS)

    Baba, Natsuki; Tanimoto, Eriko; Kobayashi, Yasuhiro; Kuma, Kouji

    2009-01-01

    We surveyed the actual conditions of mammography with regard to image quality and radiation dose at 44 facilities in Kagoshima prefecture in 1999. In April 2004, guidelines for mammography newly included the standard of digital mammography. From September to October 2005, the survey was conducted at 48 facilities, and the results of the survey were compared with that in 1999. We visited 44 of the 48 facilities, and visually evaluated the image quality of mammograms for RMI156 and clinical mammograms. In addition, we measured average mammary gland dose at each facility. The number of the mammography device that satisfied the specified guideline criterion was larger than that in 1999. Image quality for the RMI156 mammograms improved. However, the results of the present survey revealed several problems. First, the number of facilities that had quality control instruments for mammography are few. Second, radiological technologists, medical doctors, and nurses did not share knowledge or information regarding mammography. Finally, there were differences in devices and image quality for mammography among the facilities. We achieved an understanding of the actual conditions of mammography in Kagoshima prefecture by visiting many facilities, evaluating image quality, and communicating with many staff members. Our results may be useful for the development of mammography examinations. (author)

  1. Contrast Enhanced Spectral Mammography: A Review.

    Science.gov (United States)

    Patel, Bhavika K; Lobbes, M B I; Lewin, John

    2018-02-01

    Contrast-enhanced spectral mammography (CESM) provides low-energy 2D mammographic images comparable to standard digital mammography and a post-contrast recombined image to assess tumor neovascularity similar to magnetic resonance imaging (MRI). The utilization of CESM in the United States is currently low but could increase rapidly given many potential indications for clinical use. This article discusses historical background and literature review of indications and diagnostic accuracy of CESM to date. CESM is a growing technique for breast cancer detection and diagnosis that has levels of sensitivity and specificity on par with contrast-enhanced breast MRI. Because of its similar performance and ease of implementation, CESM is being adopted for multiple indications previously reserved for MRI, such as problem-solving, disease extent in newly diagnosed patients, and evaluating the treatment response of neoadjuvant chemotherapy. Copyright © 2018 Elsevier Inc. All rights reserved.

  2. Effectiveness of a Mobile Mammography Program.

    Science.gov (United States)

    Stanley, Elizabeth; Lewis, Madelene C; Irshad, Abid; Ackerman, Susan; Collins, Heather; Pavic, Dag; Leddy, Rebecca J

    2017-12-01

    Mobile mammography units have increasingly been used to address patient health care disparities; however, there are limited data comparing mobile units to stationary sites. This study aims to evaluate the characteristics of women who underwent mammography screening in a mobile unit versus those who underwent mammography screening at a cancer center. In this retrospective study, we analyzed all screening mammography examinations performed in a mobile unit in 2014 (n = 1433 examinations). For comparison, we randomized and reviewed an equivalent number of screening mammography examinations performed at our cancer center in 2014 (n = 1434 examinations). BI-RADS assessment, adherence to follow-up, biopsies performed, cancer detection rate, and sociodemographic variables were recorded. An independent-samples t test was conducted to identify potential differences in age between cancer center patients and mobile unit patients. Chi-square analyses were used to test for associations between location and factors such as health insurance, race, marital status, geographic area, adherence to screening guidelines, recall rate, adherence to follow-up, and cancer detection rates. Patients visiting our cancer center (mean = 57.74 years; SD = 10.55) were significantly older than those visiting the mobile unit (mean = 52.58 years; SD = 8.19; p mobile van (cancer center = 3.70%, mobile unit = 38.73%). There was a significant association between screening location and patient race (χ 2 = 118.75, p mobile unit = 33.30%), more black patients being screened in the mobile van (cancer center = 49.30%, mobile unit = 54.15%), and more Hispanic patients being screened in the mobile van (cancer center = 1.05%, mobile unit = 6.77%). There was a significant association between location and patient marital status (χ 2 = 135.61, p mobile unit = 38.31%), more single patients screened in the mobile van (cancer center = 25.17%, mobile unit = 34.47%), and more widowed patients being screened at the

  3. A phantom for quality control in mammography

    International Nuclear Information System (INIS)

    Gambaccini, M.; Rimondi, O.; Marziani, M.; Toti, A.

    1989-01-01

    A phantom for evaluating image quality in mammography has been designed and will be used in the Italian national programme ''Dose and Quality in Mammography''. The characteristics of the phantom are (a) about the same X-ray transmission as a 5 cm 50% fat and 50% water breast for energies between 15 and 50 keV and (b) optimum energies for imaging of the test objects (included in the phantom) in very close agreement with the optimum energies for imaging of calcifications and tumours in a 5 cm 50% fat and 50% water breast. An experimental comparison between the prototype and some commercial phantoms was carried out. Measurements are in progress to test the phantom's ability to evaluate the performances of mammographic systems quantitatively. (author)

  4. Synthesized Mammography: Clinical Evidence, Appearance, and Implementation

    Directory of Open Access Journals (Sweden)

    Melissa A. Durand

    2018-04-01

    Full Text Available Digital breast tomosynthesis (DBT has improved conventional mammography by increasing cancer detection while reducing recall rates. However, these benefits come at the cost of increased radiation dose. Synthesized mammography (s2D has been developed to provide the advantages of DBT with nearly half the radiation dose. Since its F.D.A. approval, multiple studies have evaluated the clinical performance of s2D. In clinical practice, s2D images are not identical to conventional 2D images and are designed for interpretation with DBT as a complement. This article reviews the present literature to assess whether s2D is a practical alternative to conventional 2D, addresses the differences in mammographic appearance of findings, and provides suggestions for implementation into clinical practice.

  5. Synthesized Mammography: Clinical Evidence, Appearance, and Implementation.

    Science.gov (United States)

    Durand, Melissa A

    2018-04-04

    Digital breast tomosynthesis (DBT) has improved conventional mammography by increasing cancer detection while reducing recall rates. However, these benefits come at the cost of increased radiation dose. Synthesized mammography (s2D) has been developed to provide the advantages of DBT with nearly half the radiation dose. Since its F.D.A. approval, multiple studies have evaluated the clinical performance of s2D. In clinical practice, s2D images are not identical to conventional 2D images and are designed for interpretation with DBT as a complement. This article reviews the present literature to assess whether s2D is a practical alternative to conventional 2D, addresses the differences in mammographic appearance of findings, and provides suggestions for implementation into clinical practice.

  6. Screening mammography. A risk versus risk decision

    International Nuclear Information System (INIS)

    Ritenour, E.R.; Hendee, W.R.

    1989-01-01

    The potential risk of a radiologic procedure often is compared with the potential benefit of the procedure. While risk vs. benefit analysis has been useful as a step toward increased communication and understanding among radiologists, referring physicians, and the general public, it has the disadvantage that risk and benefit are fundamentally different quantities. Hence, their juxtaposition for purposes of comparison presents contextual difficulties. In this article, the concept is presented of comparing the risk of doing a procedure with the risk of choosing not to do the procedure. An example of risk vs. risk analysis of screening mammography for women over the age of 50 is given, with the conclusion that the risk of having yearly mammograms is less than 1/10 the risk of early death caused by failure to diagnose breast cancer by x-ray mammography. This approach to risk analysis would yield interesting data for examinations that are part of more complicated diagnostic pathways.19 references

  7. Body weight and sensitivity of screening mammography

    DEFF Research Database (Denmark)

    Njor, Sisse H.; von Euler-Chelpin, My; Tjønneland, Anne

    2016-01-01

    benefit more from screening than other women. Methods: We combined data from the Danish Diet, Cancer and Health study and the organised population-based screening mammography programme in Copenhagen, Denmark. Women were categorised according to body mass index (BMI) (...Aim: Obese women tend to participate less in breast cancer screening than normal weight women. However, obese women have fattier breast than normal weight women, and screening mammography works better in fatty than in dense breasts. One might, therefore, hypothesise that obese women would actually......, and 35+). We measured recall rate, sensitivity and specificity for subsequent screens with a 2-year follow-up period. Results: The study included 6787 women. The recall rate varied from 1.4% for women with BMI women with BMI 35+, test for trend p = 0.86. Sensitivity varied from 42% (95...

  8. Breast Cancer Screening, Mammography, and Other Modalities.

    Science.gov (United States)

    Fiorica, James V

    2016-12-01

    This article is an overview of the modalities available for breast cancer screening. The modalities discussed include digital mammography, digital breast tomosynthesis, breast ultrasonography, magnetic resonance imaging, and clinical breast examination. There is a review of pertinent randomized controlled trials, studies and meta-analyses which contributed to the evolution of screening guidelines. Ultimately, 5 major medical organizations formulated the current screening guidelines in the United States. The lack of consensus in these guidelines represents an ongoing controversy about the optimal timing and method for breast cancer screening in women. For mammography screening, the Breast Imaging Reporting and Data System lexicon is explained which corresponds with recommended clinical management. The presentation and discussion of the data in this article are designed to help the clinician individualize breast cancer screening for each patient.

  9. Quality assurance programme for screen film mammography

    International Nuclear Information System (INIS)

    2009-01-01

    The application of radiation in human health, for both the diagnosis and treatment of disease, is an important component of the work of the IAEA. In the area of diagnostic radiology, this work is focused on quality assurance methods to both the promotion of the effective use of radiation for diagnostic outcome, through achieving and maintaining appropriate image quality, and also on dose determination to allow the monitoring and reduction of dose to the patient. In response to heightened awareness of the importance of patient dose contributed by radiology procedures, the IAEA published Dosimetry in Diagnostic Radiology: An International Code of Practice (Technical Reports Series No. 457) in 2007, to form a basis for patient dose determination for the Member States. Further to this, it is recognized that for complex diagnostic procedures, such as mammography, a detailed guidance document is required to give the professionals in the clinical centre the knowledge necessary to assess the patient dose, as well as to ensure that the procedure gives the maximal patient benefit possible. It is well documented that without the implementation of a quality culture and a systematic quality assurance programme with appropriate education, the detection of breast cancer cannot be made at an early enough stage to allow effective curative treatment to be undertaken. Currently there are a number of established quality assurance protocols in mammography from national and regional institutions, however, many of these protocols are distinctive and so a harmonized approach is required. This will allow the Member States to facilitate quality assurance in mammography in a standardized way which will also facilitate the introduction of national quality assurance programmes that are needed to underpin effective population screening programmes for breast cancer. Development of a quality assurance document for screen film mammography was started in 2005 with the appointment of a drafting

  10. Implementation of the qualities of radiodiagnostic: mammography

    International Nuclear Information System (INIS)

    Pacífico, Leonardo; Magalhães, Luís A.G.; Fernandes, Elisabeth; Peixoto, José Guilherme P.

    2017-01-01

    The objective of the present study was to evaluate the expanded uncertainty and present the result of the internal audit performed at the Laboratory of Radiological Sciences (LCR). The qualities of the mammographic bundles that are references in the LCR calibrations had their uncertainties and conformities with the standard evaluated. The expanded uncertainty was 1.40%, and the result of the internal audit was satisfactory. We conclude that LCR can perform calibrations on mammography qualities for end users. (author)

  11. Benefits, risks, and costs of mammography

    International Nuclear Information System (INIS)

    Richter, B.; Rausch, L.

    1977-01-01

    The risk seems to be acceptable if the age-dependency of the frequency of breast cancer is disregarded, i.e. if calculation is done with average values, as is being done frequently (15, 25, 32, 48). This procedure however veils the real circumstances in the examination of young women thus also veiling a risk which could otherwise be made precise and avoidable. The risk of radiation-induced cancerogenesis in the female breast was verified by similar statements made by several empiric investigations on man. The course of the dose-effect-relation in the region of few rad is still unexplained however, although the results do not contradict to the assumption of a linear dose-effect-relation. Thus it seems not advisable to ignore the induction of carcinomas by x-radiation for the sphere of mammography with the doses usually applied today. A reduction of radiation exposition by dose-saving measures to one tenth of the present value (or less) however would make the risk highly unimportant. Advantage/risk/cost-analyses should encourage the responsible persons to make reasonable proposals for the application of methods, in this case mammography. The discouraging of patients whom mammography is indicated for would be a side-effect which is not desired. Just as wrong would be the stimulation of an unjustified feeling of being sure and the demand for costly medical measures by uncritical reports of success. The indication of the considerably high costs of mammography should, together with the advantage expected, be a quantitative criterion for the optimal distribution of limited means the necessity of which cannot be denied. (orig.) [de

  12. Implementation of the qualities of radiodiagnostic: mammography

    Energy Technology Data Exchange (ETDEWEB)

    Pacífico, Leonardo; Magalhães, Luís A.G.; Fernandes, Elisabeth, E-mail: leonardocpacifico@gmail.com [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil); Peixoto, José Guilherme P. [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    The objective of the present study was to evaluate the expanded uncertainty and present the result of the internal audit performed at the Laboratory of Radiological Sciences (LCR). The qualities of the mammographic bundles that are references in the LCR calibrations had their uncertainties and conformities with the standard evaluated. The expanded uncertainty was 1.40%, and the result of the internal audit was satisfactory. We conclude that LCR can perform calibrations on mammography qualities for end users. (author)

  13. Estimating the relative utility of screening mammography.

    Science.gov (United States)

    Abbey, Craig K; Eckstein, Miguel P; Boone, John M

    2013-05-01

    The concept of diagnostic utility is a fundamental component of signal detection theory, going back to some of its earliest works. Attaching utility values to the various possible outcomes of a diagnostic test should, in principle, lead to meaningful approaches to evaluating and comparing such systems. However, in many areas of medical imaging, utility is not used because it is presumed to be unknown. In this work, we estimate relative utility (the utility benefit of a detection relative to that of a correct rejection) for screening mammography using its known relation to the slope of a receiver operating characteristic (ROC) curve at the optimal operating point. The approach assumes that the clinical operating point is optimal for the goal of maximizing expected utility and therefore the slope at this point implies a value of relative utility for the diagnostic task, for known disease prevalence. We examine utility estimation in the context of screening mammography using the Digital Mammographic Imaging Screening Trials (DMIST) data. We show how various conditions can influence the estimated relative utility, including characteristics of the rating scale, verification time, probability model, and scope of the ROC curve fit. Relative utility estimates range from 66 to 227. We argue for one particular set of conditions that results in a relative utility estimate of 162 (±14%). This is broadly consistent with values in screening mammography determined previously by other means. At the disease prevalence found in the DMIST study (0.59% at 365-day verification), optimal ROC slopes are near unity, suggesting that utility-based assessments of screening mammography will be similar to those found using Youden's index.

  14. Mammography with rare earth intensifying screens

    International Nuclear Information System (INIS)

    Maurer, H.J.; Goos, F.

    1987-01-01

    Screens basing on rare earth phosphors with suitable films green or blue sensitive may be used in mammography with grids without diagnostic losses. Highest definition will be obtained with medium densities on film. High-speed screens may reduce dose, but definition is poor. Best compromise between speed and high definition may be reached with relative low thickness of phosphor layers. A system of high definition films (Medichrome) and special rare earth screens give best results. (orig.) [de

  15. Mammography. [Patent750AIX-08)293916

    Energy Technology Data Exchange (ETDEWEB)

    1975-04-01

    This patent reveals a method and instrument for the detection and registration of breast cancer with the aid of X-radiation, i.e. mammography. The breast is irradiated with soft X-rays whereby the radiation beam is scanned with a moving 'stripform' screen and whereby the picture from the 'stripform' screen is recorded by a television camera that moves simultaneously with the strip. The image is then projected on a monitor.

  16. Mechanistic modeling for mammography screening risks

    International Nuclear Information System (INIS)

    Bijwaard, Harmen

    2008-01-01

    Full text: Western populations show a very high incidence of breast cancer and in many countries mammography screening programs have been set up for the early detection of these cancers. Through these programs large numbers of women (in the Netherlands, 700.000 per year) are exposed to low but not insignificant X-ray doses. ICRP based risk estimates indicate that the number of breast cancer casualties due to mammography screening can be as high as 50 in the Netherlands per year. The number of lives saved is estimated to be much higher, but for an accurate calculation of the benefits of screening a better estimate of these risks is indispensable. Here it is attempted to better quantify the radiological risks of mammography screening through the application of a biologically based model for breast tumor induction by X-rays. The model is applied to data obtained from the National Institutes of Health in the U.S. These concern epidemiological data of female TB patients who received high X-ray breast doses in the period 1930-1950 through frequent fluoroscopy of their lungs. The mechanistic model that is used to describe the increased breast cancer incidence is based on an earlier study by Moolgavkar et al. (1980), in which the natural background incidence of breast cancer was modeled. The model allows for a more sophisticated extrapolation of risks to the low dose X-ray exposures that are common in mammography screening and to the higher ages that are usually involved. Furthermore, it allows for risk transfer to other (non-western) populations. The results have implications for decisions on the frequency of screening, the number of mammograms taken at each screening, minimum and maximum ages for screening and the transfer to digital equipment. (author)

  17. Screening for breast cancer with mammography

    International Nuclear Information System (INIS)

    Sickles, E.A.

    1991-01-01

    Mammography is generally accepted as a useful problem-solving clinical tool in characterizing known breast lesions, so that appropriate and timely treatment can be given. However, it remains grossly underutilized at what it does best: screening. The major strengths of mammography are (a) its ability to detect breast cancer at a smaller, potentially more curable stage than any other examination, and (b) its proved efficacy in reducing breast cancer mortality in asymptomatic women aged 40-74. If, as has recently been estimated, screening with mammography and physical examination can be expected to lower breast cancer deaths by 40%-50% among those actually examined (13), then the lives of almost 20,000 U.S. women might be saved each year if screening were to become very widely used. The challenges of the next decade are clear, to mount much more effective campaigns to educate physicians and lay women about the life-saving benefits of breast cancer screening, to devise increasingly effective and lower cost screening strategies, to further improve the current high quality of mammographic imaging despite its increasing proliferation, and to train large numbers of breast imaging specialists to guarantee that the growing case load of screening and problem-solving mammograms is interpreted with a very high level of skill

  18. Contrast-Enhanced Spectral Mammography: Comparison with Conventional Mammography and Histopathology in 152 Women

    OpenAIRE

    Luczyńska, Elzbieta; Heinze-Paluchowska, Sylwia; Dyczek, Sonia; Blecharz, Pawel; Rys, Janusz; Reinfuss, Marian

    2014-01-01

    Objective The goal of the study was to compare conventional mammography (MG) and contrast-enhanced spectral mammography (CESM) in preoperative women. Materials and Methods The study was approved by the local Ethics Committee and all participants provided informed consent. The study included 152 consecutive patients with 173 breast lesions diagnosed on MG or CESM. All MG examinations and consults were conducted in one oncology centre. Non-ionic contrast agent, at a total dose of 1.5 mL/kg body...

  19. Mammography screening: A major issue in medicine.

    Science.gov (United States)

    Autier, Philippe; Boniol, Mathieu

    2018-02-01

    Breast cancer mortality is declining in most high-income countries. The role of mammography screening in these declines is much debated. Screening impacts cancer mortality through decreasing the incidence of number of advanced cancers with poor prognosis, while therapies and patient management impact cancer mortality through decreasing the fatality of cancers. The effectiveness of cancer screening is the ability of a screening method to curb the incidence of advanced cancers in populations. Methods for evaluating cancer screening effectiveness are based on the monitoring of age-adjusted incidence rates of advanced cancers that should decrease after the introduction of screening. Likewise, cancer-specific mortality rates should decline more rapidly in areas with screening than in areas without or with lower levels of screening but where patient management is similar. These two criteria have provided evidence that screening for colorectal and cervical cancer contributes to decreasing the mortality associated with these two cancers. In contrast, screening for neuroblastoma in children was discontinued in the early 2000s because these two criteria were not met. In addition, overdiagnosis - i.e. the detection of non-progressing occult neuroblastoma that would not have been life-threatening during the subject's lifetime - is a major undesirable consequence of screening. Accumulating epidemiological data show that in populations where mammography screening has been widespread for a long time, there has been no or only a modest decline in the incidence of advanced cancers, including that of de novo metastatic (stage IV) cancers at diagnosis. Moreover, breast cancer mortality reductions are similar in areas with early introduction and high penetration of screening and in areas with late introduction and low penetration of screening. Overdiagnosis is commonplace, representing 20% or more of all breast cancers among women invited to screening and 30-50% of screen

  20. Manifold Regularized Reinforcement Learning.

    Science.gov (United States)

    Li, Hongliang; Liu, Derong; Wang, Ding

    2018-04-01

    This paper introduces a novel manifold regularized reinforcement learning scheme for continuous Markov decision processes. Smooth feature representations for value function approximation can be automatically learned using the unsupervised manifold regularization method. The learned features are data-driven, and can be adapted to the geometry of the state space. Furthermore, the scheme provides a direct basis representation extension for novel samples during policy learning and control. The performance of the proposed scheme is evaluated on two benchmark control tasks, i.e., the inverted pendulum and the energy storage problem. Simulation results illustrate the concepts of the proposed scheme and show that it can obtain excellent performance.

  1. Mammography in Norway: Image quality and total performance

    International Nuclear Information System (INIS)

    Olsen, J.B.; Skretting, A.; Widmark, A.

    1997-04-01

    This report describes a method for assessing the total performance in mammography based on Receiver Operating Characteristic (ROC) analysis. In the time period from December 1993 to March 1994 the method was applied to assess the total performance of all the 45 Norwegian mammography laboratories operative at that time. Image quality characteristics in each laboratory was established by use of well-known phantoms

  2. THE VALUE OF ULTRASOUND MAMMOGRAPHY IN PALPABLE BREAST MASSES

    NARCIS (Netherlands)

    VANOORD, JC; VANDERVLIET, AM; THYN, CJP; MAK, B; HOOGEBOOM, GJ

    Between January 1987 and May 1988 a prospective study was carried out on 232 women with a palpable breast mass. They underwent physical examination, x-ray mammography and ultrasound mammography. The results of each study were interpreted independently by separate observers, and consensus was

  3. Patterns and determinants of mammography screening in Lebanese women

    Directory of Open Access Journals (Sweden)

    Nadia Elias

    2017-03-01

    Providing mammography free-of-charge may alleviate some obstacles among women with socio-economic disadvantage. Stressing that good results one year do not make the cancer less likely or repeating the test less important, as well as improving the comfort of mammography testing could ensure test repeating.

  4. Evaluation of breast symptoms with mammography and ultrasonography

    Directory of Open Access Journals (Sweden)

    Emine Devolli Disha

    2011-12-01

    Full Text Available Introduction: Aim of the study was to discern which are more frequent symptoms presented in malign and benign masses diagnosed by mammography and ultrasonography.Methods: Our study group consisted of 546 female patients, with breast symptoms such as palpable lumps (40.8%, pain in the breast (26%, localized lumpiness or nodularity (13.7%, nipple retraction (11.2%, nipplebloody discharge (5.1% and redness and swelling of the breast (3.1%. All 546 patients were examined by ultrasonography and mammography. Biopsy was performed according to the findings of mammography and ultrasonography.Results: In breast cancer detection ultrasonography showed an efficiency of 79.4% compared to 55.0% for mammography in detecting breast lump, in the case of nipple retraction mammography showed an efficiency of 89.1% compared to 80.4% for ultrasound, while the lowest efficiency for mammography was in the cases with localized lumpiness or nodularity 17.1% compared to 45.7% for ultrasound. In detecting fibrocystic changes where the most common symptoms was pain, ultrasonography showed an efficiency of 99.3 % compared to 84.2 % for mammography.Conclusions: Our study confirmed that breast lumps are detectable in the majority of patients with breast cancer. The most frequent symptoms in patient with benign lesions were pain or localized discomfort. The diagnostic accuracy for carcinomas of the breast and for benign lesions according to symptoms was higher for ultrasound than for mammography.

  5. Technical quality control - constancy controls for digital mammography systems

    International Nuclear Information System (INIS)

    Pedersen, K.; Landmark, I.D.; Bredholt, K.; Hauge, I.H.R.

    2009-04-01

    To ensure the quality of mammographic images, so-called constancy control tests are performed frequently. The report contains a programme for constancy control of digital mammography systems, encompassing the mammography unit, computed radiography (CR) systems, viewing conditions and displays, printers, and procedures for data collection for patient dose calculations. (Author)

  6. Breast cancer screening using tomosynthesis in combination with digital mammography.

    Science.gov (United States)

    Friedewald, Sarah M; Rafferty, Elizabeth A; Rose, Stephen L; Durand, Melissa A; Plecha, Donna M; Greenberg, Julianne S; Hayes, Mary K; Copit, Debra S; Carlson, Kara L; Cink, Thomas M; Barke, Lora D; Greer, Linda N; Miller, Dave P; Conant, Emily F

    2014-06-25

    Mammography plays a key role in early breast cancer detection. Single-institution studies have shown that adding tomosynthesis to mammography increases cancer detection and reduces false-positive results. To determine if mammography combined with tomosynthesis is associated with better performance of breast screening programs in the United States. Retrospective analysis of screening performance metrics from 13 academic and nonacademic breast centers using mixed models adjusting for site as a random effect. Period 1: digital mammography screening examinations 1 year before tomosynthesis implementation (start dates ranged from March 2010 to October 2011 through the date of tomosynthesis implementation); period 2: digital mammography plus tomosynthesis examinations from initiation of tomosynthesis screening (March 2011 to October 2012) through December 31, 2012. Recall rate for additional imaging, cancer detection rate, and positive predictive values for recall and for biopsy. A total of 454,850 examinations (n=281,187 digital mammography; n=173,663 digital mammography + tomosynthesis) were evaluated. With digital mammography, 29,726 patients were recalled and 5056 biopsies resulted in cancer diagnosis in 1207 patients (n=815 invasive; n=392 in situ). With digital mammography + tomosynthesis, 15,541 patients were recalled and 3285 biopsies resulted in cancer diagnosis in 950 patients (n=707 invasive; n=243 in situ). Model-adjusted rates per 1000 screens were as follows: for recall rate, 107 (95% CI, 89-124) with digital mammography vs 91 (95% CI, 73-108) with digital mammography + tomosynthesis; difference, -16 (95% CI, -18 to -14; P tomosynthesis; difference, 1.3 (95% CI, 0.4-2.1; P = .004); for cancer detection, 4.2 (95% CI, 3.8-4.7) with digital mammography vs 5.4 (95% CI, 4.9-6.0) with digital mammography + tomosynthesis; difference, 1.2 (95% CI, 0.8-1.6; P tomosynthesis; difference, 1.2 (95% CI, 0.8-1.6; P tomosynthesis was associated with an increase

  7. Contrast-Enhanced Spectral Mammography: Comparison with Conventional Mammography and Histopathology in 152 Women

    Energy Technology Data Exchange (ETDEWEB)

    Luczyńska, Elzbieta; Heinze-Paluchowska, Sylwia; Dyczek, Sonia [Department of Radiology, Centre of Oncology, Maria Sklodowska-Curie Memorial Institute, Krakow 31-115 (Poland); Blecharz, Pawel [Department of Gynecologic Oncology, Centre of Oncology, Maria Sklodowska-Curie Memorial Institute, Krakow 31-115 (Poland); Rys, Janusz [Department of Tumour Pathology, Centre of Oncology, Maria Sklodowska-Curie Memorial Institute, Krakow 31-115 (Poland); Reinfuss, Marian [Department of Radiotherapy, Centre of Oncology, Maria Sklodowska-Curie Memorial Institute, Krakow 31-115 (Poland)

    2014-07-01

    The goal of the study was to compare conventional mammography (MG) and contrast-enhanced spectral mammography (CESM) in preoperative women. The study was approved by the local Ethics Committee and all participants provided informed consent. The study included 152 consecutive patients with 173 breast lesions diagnosed on MG or CESM. All MG examinations and consults were conducted in one oncology centre. Non-ionic contrast agent, at a total dose of 1.5 mL/kg body weight, was injected intravenous. Subsequently, CESM exams were performed with a mammography device, allowing dual-energy acquisitions. The entire procedure was done within the oncology centre. Images from low and high energy exposures were processed together and the combination provided an 'iodine' image which outlined contrast up-take in the breast. MG detected 157 lesions in 150 patients, including 92 infiltrating cancers, 12 non-infiltrating cancers, and 53 benign lesions. CESM detected 149 lesions in 128 patients, including 101 infiltrating cancers, 13 non-infiltrating cancers, and 35 benign lesions. CESM sensitivity was 100% (vs. 91% for MG), specificity was 41% (vs. 15% for MG), area under the receiver operating characteristic curve was 0.86 (vs. 0.67 for MG), and accuracy was 80% (vs. 65% for MG) for the diagnosis of breast cancer. Both MG and CESM overestimated lesion sizes compared to histopathology (p < 0.001). CESM may provide higher sensitivity for breast cancer detection and greater diagnostic accuracy than conventional mammography.

  8. Contrast-enhanced spectral mammography: comparison with conventional mammography and histopathology in 152 women.

    Science.gov (United States)

    Luczyńska, Elzbieta; Heinze-Paluchowska, Sylwia; Dyczek, Sonia; Blecharz, Pawel; Rys, Janusz; Reinfuss, Marian

    2014-01-01

    The goal of the study was to compare conventional mammography (MG) and contrast-enhanced spectral mammography (CESM) in preoperative women. The study was approved by the local Ethics Committee and all participants provided informed consent. The study included 152 consecutive patients with 173 breast lesions diagnosed on MG or CESM. All MG examinations and consults were conducted in one oncology centre. Non-ionic contrast agent, at a total dose of 1.5 mL/kg body weight, was injected intravenous. Subsequently, CESM exams were performed with a mammography device, allowing dual-energy acquisitions. The entire procedure was done within the oncology centre. Images from low and high energy exposures were processed together and the combination provided an "iodine" image which outlined contrast up-take in the breast. MG detected 157 lesions in 150 patients, including 92 infiltrating cancers, 12 non-infiltrating cancers, and 53 benign lesions. CESM detected 149 lesions in 128 patients, including 101 infiltrating cancers, 13 non-infiltrating cancers, and 35 benign lesions. CESM sensitivity was 100% (vs. 91% for MG), specificity was 41% (vs. 15% for MG), area under the receiver operating characteristic curve was 0.86 (vs. 0.67 for MG), and accuracy was 80% (vs. 65% for MG) for the diagnosis of breast cancer. Both MG and CESM overestimated lesion sizes compared to histopathology (p mammography.

  9. Average glandular dose in routine mammography screening using a Sectra Microdose Mammography unit

    International Nuclear Information System (INIS)

    Hemdal, B.; Herrnsdorf, L.; Andersson, I.; Bengtsson, G.; Heddson, B.; Olsson, M.

    2005-01-01

    The Sectra MicroDose Mammography system is based on direct photon counting (with a solid-state detector), and a substantially lower dose to the breast than when using conventional system can be expected. In this work absorbed dose measurements have been performed for the first unit used in routine mammography screening (at the Hospitals of Helsingborg (Sweden)). Two European protocols on dosimetry in mammography have been followed. Measurement of half value layer (HVL) cannot be performed as prescribed, but this study has demonstrated than non-invasive measurements of HVL can be performed accurately with a sensitive and well collimated solid-state detector with simultaneous correction for the energy dependence. The average glandular dose for a 50 mm standard breast with 50% glandularity, simulated by 45 mm polymethylmethacrylate, was found to be 0.21 and 0.28 mGy in March and December 2004, respectively. These values are much lower than for any other mammography system on the market today. It has to be stressed that the measurement were made using the current clinical settings and that no systematic optimisation of the relationship between absorbed dose and diagnostic image quality has been performed within the present study. In order to further increase the accuracy of absorbed dose measurements for this unit, the existing dose protocols should be revised to account also for the tungsten/aluminium anode/filter combination, the multi-slit pre-collimator device and the occurrence of a dose profile in the scanning direction. (authors)

  10. Contrast-Enhanced Spectral Mammography: Comparison with Conventional Mammography and Histopathology in 152 Women

    International Nuclear Information System (INIS)

    Luczyńska, Elzbieta; Heinze-Paluchowska, Sylwia; Dyczek, Sonia; Blecharz, Pawel; Rys, Janusz; Reinfuss, Marian

    2014-01-01

    The goal of the study was to compare conventional mammography (MG) and contrast-enhanced spectral mammography (CESM) in preoperative women. The study was approved by the local Ethics Committee and all participants provided informed consent. The study included 152 consecutive patients with 173 breast lesions diagnosed on MG or CESM. All MG examinations and consults were conducted in one oncology centre. Non-ionic contrast agent, at a total dose of 1.5 mL/kg body weight, was injected intravenous. Subsequently, CESM exams were performed with a mammography device, allowing dual-energy acquisitions. The entire procedure was done within the oncology centre. Images from low and high energy exposures were processed together and the combination provided an 'iodine' image which outlined contrast up-take in the breast. MG detected 157 lesions in 150 patients, including 92 infiltrating cancers, 12 non-infiltrating cancers, and 53 benign lesions. CESM detected 149 lesions in 128 patients, including 101 infiltrating cancers, 13 non-infiltrating cancers, and 35 benign lesions. CESM sensitivity was 100% (vs. 91% for MG), specificity was 41% (vs. 15% for MG), area under the receiver operating characteristic curve was 0.86 (vs. 0.67 for MG), and accuracy was 80% (vs. 65% for MG) for the diagnosis of breast cancer. Both MG and CESM overestimated lesion sizes compared to histopathology (p < 0.001). CESM may provide higher sensitivity for breast cancer detection and greater diagnostic accuracy than conventional mammography

  11. Reproducibility of Mammography Units, Film Processing and Quality Imaging

    International Nuclear Information System (INIS)

    Gaona, Enrique

    2003-01-01

    The purpose of this study was to carry out an exploratory survey of the problems of quality control in mammography and processors units as a diagnosis of the current situation of mammography facilities. Measurements of reproducibility, optical density, optical difference and gamma index are included. Breast cancer is the most frequently diagnosed cancer and is the second leading cause of cancer death among women in the Mexican Republic. Mammography is a radiographic examination specially designed for detecting breast pathology. We found that the problems of reproducibility of AEC are smaller than the problems of processors units because almost all processors fall outside of the acceptable variation limits and they can affect the mammography quality image and the dose to breast. Only four mammography units agree with the minimum score established by ACR and FDA for the phantom image

  12. Performance of clinical mammography: a nationwide study from Denmark

    DEFF Research Database (Denmark)

    Jensen, Allan; Vejborg, Ilse; Severinsen, Niels

    2006-01-01

    that clinical mammography worked best in patient populations of purely symptomatic women. Our data indicate that to increase the accuracy of clinical mammography at the community level, the presence of an experienced radiologist should be prioritized ahead of raising the clinic size.......Clinical mammography is the key tool for breast cancer diagnosis, but little is known about the impact of the organisational set-up on the performance. We evaluated whether organisational factors influence the performance of clinical mammography. Clinical mammography data from all clinics...... in Denmark in the year 2000 were collected and linked to cancer outcome. Use of the National Institute of Radiation Hygiene register for identification of radiology clinics ensured comprehensive nationwide registration. We used the final mammographic assessment at the end of the imaging work-up to determine...

  13. Descriptive study of the quality control in mammography

    International Nuclear Information System (INIS)

    Gaona, E.; Perdigon C, G.M.; Casian C, G.A.; Azorin N, J.; Diaz G, J.A.I.; Arreola, M.

    2005-01-01

    The goal of mammography is to provide contrast between a lesion that is possible residing within the breast and normal surrounding tissue. Quality control is essential for maintaining the contrast imaging performance of a mammography system and incorporate tests that are relevant in that they are predictive of future degradation of contrast imaging performance. These tests will also be done at frequency that is high enough to intercept most drifts in quality imaging or performance before they become diagnostically significant. The quality control study has as objective to describe the results of the assessment of quality imaging elements (film optical density, contrast (density difference), uniformity, resolution and noise) of 62 mammography departments without quality control program and comparison these results with a mammography reference department with a quality control program. When comparing the results they allow seeing the clinical utility of to have a quality control program to reduce the errors of mammography interpretation. (Author)

  14. Establishment of dose reference levels for mammography in Greece

    International Nuclear Information System (INIS)

    Kalathaki, M.; Hourdakis, C.J.; Economides, S.; Tritakis, P.; Manousaridis, G.; Kalyvas, N.; Simantirakis, G.; Kipouros, P.; Kamenopoulou, V.

    2006-01-01

    Full text of publication follows: Diagnostic Reference Levels (D.R.L.) are dose levels established in medical practices for typical x-ray examinations concerning groups of standard size patients or standard phantoms and broadly defined types of equipment. When good and normal practice is performed, these levels are not expected to be exceeded. This work is an attempt to establish for the first time the D.R.L. for mammography in Greece. At present, there are 402 mammographic systems in clinical use all over the country. This study that lasted 3 years (2000-2003), includes 117 of these systems, 85% of which are installed in private and 15% in public sector countrywide. Measurements of entrance surface dose (E.S.D.) were performed as a part of the regular inspections performed by the Licensing and Inspections Department of Greek Atomic Energy Commission on the basis of the laboratories licensing procedure. Moreover, the entire performance of the mammographic units was assessed by quantitative and qualitative measurements of specific parameters. In order to establish the national D.R.L., a standard phantom was used during the quality control of the mammographic units and E.S.D. measurements were performed based on the clinical practice of each laboratory. The D.R.L. for this type of examination was established according to the 75. percentile of the E.S.D. curve and found equal to 7 mGy per single view. The comparison of this value with the one reported by the European Commission (10 mGy per view), indicates that the D.R.L. for mammography is lower in Greece. However, the primary concern of a mammographic examination is to keep breast dose as low as reasonably achievable while providing images with the maximum amount of diagnostic information. The quality of the produced images was therefore assessed for all systems examined, regardless of meeting or exceeding the quality criteria reference surface entrance dose. The results showed that the average total score of the

  15. Contrast-enhanced spectral mammography vs. mammography and MRI - clinical performance in a multi-reader evaluation

    NARCIS (Netherlands)

    Fallenberg, E.M.; Schmitzberger, F.F.; Amer, H.; Ingold-Heppner, B.; Balleyguier, C.; Diekmann, F.; Engelken, F.; Mann, R.M.; Renz, D.M.; Bick, U.; Hamm, B.; Dromain, C.

    2017-01-01

    OBJECTIVES: To compare the diagnostic performance of contrast-enhanced spectral mammography (CESM) to digital mammography (MG) and magnetic resonance imaging (MRI) in a prospective two-centre, multi-reader study. METHODS: One hundred seventy-eight women (mean age 53 years) with invasive breast

  16. Implementation of Quality Control Protocol in Mammography: A Serbian Experience

    International Nuclear Information System (INIS)

    Ciraj Bjelac, O.; Kosutic, D.; Arandjic, D.; Kovacevic, M.

    2008-01-01

    Mammography is method of choice for early detection of breast cancer. In Serbia, mammography is performed only clinically, although there is a long term plan to introduce mammography as screening method. Currently there are 60 mammography units in practice in Serbia, resulting with 70 000 mammographies annually. The purpose of this paper is preliminary evaluation of the mammography practice in Serbia, having in mind the annual number of examinations and fact that part of examination is performed on women without any clinical signs. For pilot implementation of Quality Control (QC) protocol in mammography, five hospitals with highest workload have been selected, representing the typical mammography practice in Serbia. Developed QC protocol, based on European guidelines for quality assurance in breast cancer screening and diagnosis, actual practice and resources, includes equipment testing and maintenance, staff training and QC management and allocation of responsibilities. Subsequently, it should be applied on the national scale. The survey demonstrated considerable variations in technical parameters that affect image quality and patients doses. Mean glandular doses ranged from 0.12 to 2.8 mGy, while reference optical density ranged from 1.2 to 2.8. Main problems were associated with film processing, viewing conditions and optical density control. The preliminary survey of mammography practice highlighted the need for optimization of radiation protection and training of operating staff, although the survey itself was very valuable learning process for all participants. Furthermore, systematic implementation of QC protocol should provide reliable performance of mammography units and maintain satisfactory image quality and keep patient doses as low as reasonably practical.(author)

  17. TL dosimetry for quality control of CR mammography imaging systems

    Science.gov (United States)

    Gaona, E.; Nieto, J. A.; Góngora, J. A. I. D.; Arreola, M.; Enríquez, J. G. F.

    The aim of this work is to estimate the average glandular dose with thermoluminescent (TL) dosimetry and comparison with quality imaging in computed radiography (CR) mammography. For a measuring dose, the Food and Drug Administration (FDA) and the American College of Radiology (ACR) use a phantom, so that dose and image quality are assessed with the same test object. The mammography is a radiological image to visualize early biological manifestations of breast cancer. Digital systems have two types of image-capturing devices, full field digital mammography (FFDM) and CR mammography. In Mexico, there are several CR mammography systems in clinical use, but only one system has been approved for use by the FDA. Mammography CR uses a photostimulable phosphor detector (PSP) system. Most CR plates are made of 85% BaFBr and 15% BaFI doped with europium (Eu) commonly called barium flourohalideE We carry out an exploratory survey of six CR mammography units from three different manufacturers and six dedicated X-ray mammography units with fully automatic exposure. The results show three CR mammography units (50%) have a dose greater than 3.0 mGy without demonstrating improved image quality. The differences between doses averages from TLD system and dosimeter with ionization chamber are less than 10%. TLD system is a good option for average glandular dose measurement for X-rays with a HVL (0.35-0.38 mmAl) and kVp (24-26) used in quality control procedures with ACR Mammography Accreditation Phantom.

  18. Diverse Regular Employees and Non-regular Employment (Japanese)

    OpenAIRE

    MORISHIMA Motohiro

    2011-01-01

    Currently there are high expectations for the introduction of policies related to diverse regular employees. These policies are a response to the problem of disparities between regular and non-regular employees (part-time, temporary, contract and other non-regular employees) and will make it more likely that workers can balance work and their private lives while companies benefit from the advantages of regular employment. In this paper, I look at two issues that underlie this discussion. The ...

  19. Sparse structure regularized ranking

    KAUST Repository

    Wang, Jim Jing-Yan

    2014-04-17

    Learning ranking scores is critical for the multimedia database retrieval problem. In this paper, we propose a novel ranking score learning algorithm by exploring the sparse structure and using it to regularize ranking scores. To explore the sparse structure, we assume that each multimedia object could be represented as a sparse linear combination of all other objects, and combination coefficients are regarded as a similarity measure between objects and used to regularize their ranking scores. Moreover, we propose to learn the sparse combination coefficients and the ranking scores simultaneously. A unified objective function is constructed with regard to both the combination coefficients and the ranking scores, and is optimized by an iterative algorithm. Experiments on two multimedia database retrieval data sets demonstrate the significant improvements of the propose algorithm over state-of-the-art ranking score learning algorithms.

  20. Colour application on mammography image segmentation

    Science.gov (United States)

    Embong, R.; Aziz, N. M. Nik Ab.; Karim, A. H. Abd; Ibrahim, M. R.

    2017-09-01

    The segmentation process is one of the most important steps in image processing and computer vision since it is vital in the initial stage of image analysis. Segmentation of medical images involves complex structures and it requires precise segmentation result which is necessary for clinical diagnosis such as the detection of tumour, oedema, and necrotic tissues. Since mammography images are grayscale, researchers are looking at the effect of colour in the segmentation process of medical images. Colour is known to play a significant role in the perception of object boundaries in non-medical colour images. Processing colour images require handling more data, hence providing a richer description of objects in the scene. Colour images contain ten percent (10%) additional edge information as compared to their grayscale counterparts. Nevertheless, edge detection in colour image is more challenging than grayscale image as colour space is considered as a vector space. In this study, we implemented red, green, yellow, and blue colour maps to grayscale mammography images with the purpose of testing the effect of colours on the segmentation of abnormality regions in the mammography images. We applied the segmentation process using the Fuzzy C-means algorithm and evaluated the percentage of average relative error of area for each colour type. The results showed that all segmentation with the colour map can be done successfully even for blurred and noisy images. Also the size of the area of the abnormality region is reduced when compare to the segmentation area without the colour map. The green colour map segmentation produced the smallest percentage of average relative error (10.009%) while yellow colour map segmentation gave the largest percentage of relative error (11.367%).

  1. Radiation hazards of X-ray mammography

    International Nuclear Information System (INIS)

    Bailar, J.C. III

    1978-01-01

    X-ray mammography delivers significant amounts of ionizing radiation to the breast, and the female breast is more susceptible to radiation carcinogenesis than any other human organ. On the other hand, breast cancer is least likely to cause serious illness and death when it is detected at a very early stage. The risks and benefits of mammography can be estimated. This paper summarizes current risk estimates, then proceeds to a comparison of risks and benefits. As for breast cancer mortality, the addition of mammography to a programme of annual breast examinations of average U.S. women is of questionable value for women under age 50 but it is probably beneficial for older women. However, the break-even point is closely related to the average radiation exposure of breast tissue, and would be earlier in a few centres now using optimum techniques and equipment. For women with below-average risks of breast cancer, the age would be higher, and for a few women with a high probability of developing breast cancer it would be lower. Breast cancer screening programmes have been improved significantly since criticisms were first publicized in mid-1975. Partial improvements include reduction in radiation exposure (at least in some centres), guidelines from the National Cancer Institute (NCI) and the American Cancer Society (ACS) for restricting the screening of women under age 50, and changes in the patient consent form signed by participants in the NCI-ACS programme. Professional and public awareness of the need to balance the benefits of screening with its risks and costs has rapidly and markedly increased. Future improvements should further define the optimum design and application of breast cancer screening programmes

  2. Thyroid absorbed dose using TLDs during mammography

    International Nuclear Information System (INIS)

    Gonzalez A, M.; Melendez L, M.; Davila M, P.

    2015-10-01

    Full text: In this study, the mean glandular dose (MGD) and the thyroid dose (D Thy) were measured in 200 women screened with mammography in Cranio caudal (Cc) and mediolateral oblique projections. All mammograms were performed with Giotto-Ims (6000-14-M2 Model) equipment, which was verified to meet the criteria of quality of NOM-229-Ssa-2002. During audits performance and HVL, for each anode filter combinations was measured with the camera Radcal mammography equipment 10 X 6-6M (HVL = 0.26 mm Al). D Thy measurements were performed with TLD dosimeters (LiF:Mn) , that were read with the Harshaw 3500 TLD reader. The MGD, was obtained according to the UK and European protocols for mammographic dosimetry using a plane parallel chamber (Standard Imaging, Model A-600) calibrated by a radiation beam UW-23-Mo (= 0.279 mm Al HVL). A comparative statistical analysis was carried out with the measured MGD and D thy. The thyroid mean dose was 0.063 mGy and 0.078 mGy for Cc and mediolateral oblique respectively. There is a linear correlation between the MGD and the D Thy slightly influenced by the anode-filter combination. Using a 95% for the confidence interval in MGD (1.07 mGy), the 90% of measurements are in agreement with the established uncertainty limits. The D Thy are lower than the MGD. There is no risk for cancer induction in thyroid in women due to mammography screening. (Author)

  3. 'Regular' and 'emergency' repair

    International Nuclear Information System (INIS)

    Luchnik, N.V.

    1975-01-01

    Experiments on the combined action of radiation and a DNA inhibitor using Crepis roots and on split-dose irradiation of human lymphocytes lead to the conclusion that there are two types of repair. The 'regular' repair takes place twice in each mitotic cycle and ensures the maintenance of genetic stability. The 'emergency' repair is induced at all stages of the mitotic cycle by high levels of injury. (author)

  4. Regularization of divergent integrals

    OpenAIRE

    Felder, Giovanni; Kazhdan, David

    2016-01-01

    We study the Hadamard finite part of divergent integrals of differential forms with singularities on submanifolds. We give formulae for the dependence of the finite part on the choice of regularization and express them in terms of a suitable local residue map. The cases where the submanifold is a complex hypersurface in a complex manifold and where it is a boundary component of a manifold with boundary, arising in string perturbation theory, are treated in more detail.

  5. Regularizing portfolio optimization

    International Nuclear Information System (INIS)

    Still, Susanne; Kondor, Imre

    2010-01-01

    The optimization of large portfolios displays an inherent instability due to estimation error. This poses a fundamental problem, because solutions that are not stable under sample fluctuations may look optimal for a given sample, but are, in effect, very far from optimal with respect to the average risk. In this paper, we approach the problem from the point of view of statistical learning theory. The occurrence of the instability is intimately related to over-fitting, which can be avoided using known regularization methods. We show how regularized portfolio optimization with the expected shortfall as a risk measure is related to support vector regression. The budget constraint dictates a modification. We present the resulting optimization problem and discuss the solution. The L2 norm of the weight vector is used as a regularizer, which corresponds to a diversification 'pressure'. This means that diversification, besides counteracting downward fluctuations in some assets by upward fluctuations in others, is also crucial because it improves the stability of the solution. The approach we provide here allows for the simultaneous treatment of optimization and diversification in one framework that enables the investor to trade off between the two, depending on the size of the available dataset.

  6. Regularizing portfolio optimization

    Science.gov (United States)

    Still, Susanne; Kondor, Imre

    2010-07-01

    The optimization of large portfolios displays an inherent instability due to estimation error. This poses a fundamental problem, because solutions that are not stable under sample fluctuations may look optimal for a given sample, but are, in effect, very far from optimal with respect to the average risk. In this paper, we approach the problem from the point of view of statistical learning theory. The occurrence of the instability is intimately related to over-fitting, which can be avoided using known regularization methods. We show how regularized portfolio optimization with the expected shortfall as a risk measure is related to support vector regression. The budget constraint dictates a modification. We present the resulting optimization problem and discuss the solution. The L2 norm of the weight vector is used as a regularizer, which corresponds to a diversification 'pressure'. This means that diversification, besides counteracting downward fluctuations in some assets by upward fluctuations in others, is also crucial because it improves the stability of the solution. The approach we provide here allows for the simultaneous treatment of optimization and diversification in one framework that enables the investor to trade off between the two, depending on the size of the available dataset.

  7. A PET imaging system dedicated to mammography

    CERN Document Server

    Varela, J

    2007-01-01

    The imaging system Clear-PEM for positron emission mammography, under development within the framework of the Crystal Clear Collaboration at CERN, is presented. The detector is based on pixelized LYSO crystals optically coupled to avalanche photodiodes (APD) and readout by a fast low-noise electronic system. A dedicated digital trigger and data acquisition system is used for on-line selection of coincidence events with high efficiency, large bandwidth and negligible dead-time. The detector module performance was characterized in detail.

  8. Implementation of the qualities of radiodiagnostic: mammography

    Science.gov (United States)

    Pacífico, L. C.; Magalhães, L. A. G.; Peixoto, J. G. P.; Fernandes, E.

    2018-03-01

    The objective of the present study was to evaluate the expanded uncertainty of the mammographic calibration process and present the result of the internal audit performed at the Laboratory of Radiological Sciences (LCR). The qualities of the mammographic beans that are references in the LCR, comprises two irradiation conditions: no-attenuated beam and attenuated beam. Both had satisfactory results, with an expanded uncertainty equals 2,1%. The internal audit was performed, and the degree of accordance with the ISO/IEC 17025 was evaluated. The result of the internal audit was satisfactory. We conclude that LCR can perform calibrations on mammography qualities for end users.

  9. A computer simulation study comparing lesion detection accuracy with digital mammography, breast tomosynthesis, and cone-beam CT breast imaging

    International Nuclear Information System (INIS)

    Gong Xing; Glick, Stephen J.; Liu, Bob; Vedula, Aruna A.; Thacker, Samta

    2006-01-01

    Although conventional mammography is currently the best modality to detect early breast cancer, it is limited in that the recorded image represents the superposition of a three-dimensional (3D) object onto a 2D plane. Recently, two promising approaches for 3D volumetric breast imaging have been proposed, breast tomosynthesis (BT) and CT breast imaging (CTBI). To investigate possible improvements in lesion detection accuracy with either breast tomosynthesis or CT breast imaging as compared to digital mammography (DM), a computer simulation study was conducted using simulated lesions embedded into a structured 3D breast model. The computer simulation realistically modeled x-ray transport through a breast model, as well as the signal and noise propagation through a CsI based flat-panel imager. Polyenergetic x-ray spectra of Mo/Mo 28 kVp for digital mammography, Mo/Rh 28 kVp for BT, and W/Ce 50 kVp for CTBI were modeled. For the CTBI simulation, the intensity of the x-ray spectra for each projection view was determined so as to provide a total average glandular dose of 4 mGy, which is approximately equivalent to that given in conventional two-view screening mammography. The same total dose was modeled for both the DM and BT simulations. Irregular lesions were simulated by using a stochastic growth algorithm providing lesions with an effective diameter of 5 mm. Breast tissue was simulated by generating an ensemble of backgrounds with a power law spectrum, with the composition of 50% fibroglandular and 50% adipose tissue. To evaluate lesion detection accuracy, a receiver operating characteristic (ROC) study was performed with five observers reading an ensemble of images for each case. The average area under the ROC curves (A z ) was 0.76 for DM, 0.93 for BT, and 0.94 for CTBI. Results indicated that for the same dose, a 5 mm lesion embedded in a structured breast phantom was detected by the two volumetric breast imaging systems, BT and CTBI, with statistically

  10. Mammography - recent technical developments and their clinical potential

    Energy Technology Data Exchange (ETDEWEB)

    Hemdal, Bengt; Mattsson, Soeren [Malmoe Univ. Hospital (Sweden). Dept. of Radiation Physics; Andersson, Ingvar [Malmoe Univ. Hospital (Sweden). Dept. of Diagnostic Radiology; Thilander Klang, Anne [Sahlgrenska Univ. Hospital, Goeteborg (Sweden). Dept. of Medical Physics and Biomedical Engineering; Bengtsson, Gert; Jarlman, O. [Lund Univ. Hospital (Sweden). Dept. of Diagnostic Radiology; Leitz, Wolfram [Swedish Radiation Protection Authority, Stockholm (Sweden); Bjurstam, Nils [Univ. of North Norway, Troms (Norway). Dept. of Radiology

    2002-05-01

    The recent technical developments in digital as well as screen-film X-ray mammography have been reviewed in order to evaluate their clinical potential and to analyse possible lines for future development. Material and methods: The scientific literature has been reviewed, conferences covered and contacts with colleagues developed. Companies in the field have been inquired and invited for presentations. Own experience has been gathered from different screen-film and digital mammography systems. Results and conclusions: Although there are important complementary techniques such as ultrasound and magnetic resonance imaging (MRI), X-ray mammography is still the golden standard for breast imaging. It is relatively simple and cost-effective, and it is presently the only realistic technique for screening in a large scale. It is still largely the only technique that can detect breast cancer in a pre invasive stage. Equipment for digital mammography is commercially available both with small area and full field technique (FFDM). The development of FFDM systems is now intense, as well as the development of dedicated workstations and computer-aided detection (CAD). In spite of this, the introduction of digital mammography has been very slow compared to most other X-ray examinations due to high costs and technical challenges to meet the high demands on image quality and dose in mammography as well as the demands on specialised workflow support for screening mammography and suitable display techniques. Film reading of digital mammograms has been the most common display mode so far, but to take full advantage of the digital concept, diagnostic as well as logistic, monitor reading must be applied. There is a potential of FFDM systems for significantly higher image quality or significantly lower dose than screen-film mammography (SFM), or both. Further research is necessary to fully use this potential. The investment costs are much higher for digital than screen-film mammography

  11. Mammography - recent technical developments and their clinical potential

    International Nuclear Information System (INIS)

    Hemdal, Bengt; Mattsson, Soeren; Bjurstam, Nils

    2002-05-01

    The recent technical developments in digital as well as screen-film X-ray mammography have been reviewed in order to evaluate their clinical potential and to analyse possible lines for future development. Material and methods: The scientific literature has been reviewed, conferences covered and contacts with colleagues developed. Companies in the field have been inquired and invited for presentations. Own experience has been gathered from different screen-film and digital mammography systems. Results and conclusions: Although there are important complementary techniques such as ultrasound and magnetic resonance imaging (MRI), X-ray mammography is still the golden standard for breast imaging. It is relatively simple and cost-effective, and it is presently the only realistic technique for screening in a large scale. It is still largely the only technique that can detect breast cancer in a pre invasive stage. Equipment for digital mammography is commercially available both with small area and full field technique (FFDM). The development of FFDM systems is now intense, as well as the development of dedicated workstations and computer-aided detection (CAD). In spite of this, the introduction of digital mammography has been very slow compared to most other X-ray examinations due to high costs and technical challenges to meet the high demands on image quality and dose in mammography as well as the demands on specialised workflow support for screening mammography and suitable display techniques. Film reading of digital mammograms has been the most common display mode so far, but to take full advantage of the digital concept, diagnostic as well as logistic, monitor reading must be applied. There is a potential of FFDM systems for significantly higher image quality or significantly lower dose than screen-film mammography (SFM), or both. Further research is necessary to fully use this potential. The investment costs are much higher for digital than screen-film mammography

  12. Regular Single Valued Neutrosophic Hypergraphs

    Directory of Open Access Journals (Sweden)

    Muhammad Aslam Malik

    2016-12-01

    Full Text Available In this paper, we define the regular and totally regular single valued neutrosophic hypergraphs, and discuss the order and size along with properties of regular and totally regular single valued neutrosophic hypergraphs. We also extend work on completeness of single valued neutrosophic hypergraphs.

  13. The geometry of continuum regularization

    International Nuclear Information System (INIS)

    Halpern, M.B.

    1987-03-01

    This lecture is primarily an introduction to coordinate-invariant regularization, a recent advance in the continuum regularization program. In this context, the program is seen as fundamentally geometric, with all regularization contained in regularized DeWitt superstructures on field deformations

  14. Quality control in digital mammography: the noise components

    International Nuclear Information System (INIS)

    Leyton, Fernando; Nogueira, Maria do Socorro; Duran, Maria Paz; Dantas, Marcelino; Ubeda, Carlos

    2011-01-01

    To measure the linearity of the detector and determine the noise components (quantum, electronic and structural noise) that contributed to losing image quality and to determine the signal noise ratio (SNR) and contrast noise ratio (CNR). This paper describes the results of the implementation of a protocol for quality control in digital mammography performed in two direct digital mammography equipment (Hologic, Selenia) in Santiago of Chile. Shows the results of linearity and noise analysis of the images which establishes the main cause of noise in the image of the mammogram to ensure the quality and optimize procedures. The study evaluated two digital mammography's Selenia, Hologic (DR) from Santiago, Chile. We conducted the assessment of linearity of the detector, the signal noise ratio, contrast noise ratio and was determined the contribution of different noise components (quantum, electronics and structural noise). Used different thicknesses used in clinical practice according to the protocol for quality control in digital mammography of Spanish society of medical physics and NHSBSP Equipment Report 0604 Version 3. The Selenia mammography software was used for the analysis of images and Unfors Xi detector for measuring doses. The mammography detector has a linear performance, the CNR and SNR did not comply with the Protocol for the thicknesses of 60 and 70 mm. The main contribution of the noise corresponds to the quantum noise, therefore it is necessary to adjust and optimize the mammography system. (author)

  15. Quality control in digital mammography: the noise components

    Energy Technology Data Exchange (ETDEWEB)

    Leyton, Fernando [Universidade de Tarapaca, Arica (Chile). Centro de Estudios en Ciencias Radiologicas; Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Nogueira, Maria do Socorro, E-mail: mnogue@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Duran, Maria Paz [Clinica Alemana, Santiago (Chile). Dept. de Radiologia; Dantas, Marcelino, E-mail: marcelino@inb.gov.b [Industrias Nucleares do Brasil (INB), Caldas, MG (Brazil). Unidade de Tratamento de Minerios; Ubeda, Carlos, E-mail: cubeda@uta.c [Universidade de Tarapaca, Arica (Chile). Fac. de Ciencias de la Salud

    2011-07-01

    To measure the linearity of the detector and determine the noise components (quantum, electronic and structural noise) that contributed to losing image quality and to determine the signal noise ratio (SNR) and contrast noise ratio (CNR). This paper describes the results of the implementation of a protocol for quality control in digital mammography performed in two direct digital mammography equipment (Hologic, Selenia) in Santiago of Chile. Shows the results of linearity and noise analysis of the images which establishes the main cause of noise in the image of the mammogram to ensure the quality and optimize procedures. The study evaluated two digital mammography's Selenia, Hologic (DR) from Santiago, Chile. We conducted the assessment of linearity of the detector, the signal noise ratio, contrast noise ratio and was determined the contribution of different noise components (quantum, electronics and structural noise). Used different thicknesses used in clinical practice according to the protocol for quality control in digital mammography of Spanish society of medical physics and NHSBSP Equipment Report 0604 Version 3. The Selenia mammography software was used for the analysis of images and Unfors Xi detector for measuring doses. The mammography detector has a linear performance, the CNR and SNR did not comply with the Protocol for the thicknesses of 60 and 70 mm. The main contribution of the noise corresponds to the quantum noise, therefore it is necessary to adjust and optimize the mammography system. (author)

  16. Mammography and ultrasound in the evaluation of male breast disease

    Energy Technology Data Exchange (ETDEWEB)

    Munoz Carrasco, Rafaela; Alvarez Benito, Marina; Raya Povedano, Jose Luis [Hospital Universitario ' Reina Sofia' , Radiology Department, Cordoba (Spain); Munoz Gomariz, Elisa [Hospital Universitario ' Reina Sofia' , Support Unit for Research, Cordoba (Spain); Martinez Paredes, Maria [University of Cordoba, Radiology and Physical Medicine Area, Cordoba (Spain)

    2010-12-15

    To assess clinical variables that may be useful in differentiating gynaecomastia from carcinoma and to analyse the contribution of mammography and ultrasound to the evaluation of male breast disease. All men who underwent mammography and/or ultrasound between 1993 and 2006 in our hospital were retrospectively evaluated. Clinical characteristics in patients with gynaecomastia and those with carcinoma were compared. Radiological findings were classified according to the BI-RADS (Breast Imaging Reporting and Data System) criteria. The diagnostic performance of physical examination, mammography and ultrasound was determined and compared. A total of 628 patients with 518 mammograms and 423 ultrasounds were reviewed. The final diagnoses were: 19 carcinomas, 526 gynaecomastias, 84 other benign conditions and 25 normal. There were statistically significant differences in age, bilateral involvement, clinical presentation and physical examination between patients with carcinoma and those with gynaecomastia. The diagnostic performance of physical examination was lower than that of mammography and ultrasound (p < 0.05 for specificity). Mammography was the most sensitive (94.7%) and ultrasound the most specific (95.3%) for detection of malignancy (p > 0.05). We propose an algorithm for the use of mammography and ultrasound in men. Mammography and ultrasound, with a negative predictive value close to 100%, make it possible to avoid very many unnecessary surgical procedures in men. (orig.)

  17. Traceability and quality control in mammography: measurements and models

    International Nuclear Information System (INIS)

    Peixoto, Jose Guilherme Pereira

    2002-10-01

    The success of a treatment or diagnosis using radiation, depends on the optimization of the dose determination to be administered for the patient and on the beam radiation quality. It is recognized by the international guidelines that it is necessary to improve calibration services for mammography beams in order to improve the quality of clinical diagnosis. Major efforts have been made by several laboratories in order to establish an appropriate and traceable calibration infrastructure and to provide the basis for a quality control program in mammography. The contribution of the radiation metrology network to the mammography services is reviewed in this work. Steps required for the implementation of a mammography calibration system using a constant potential x-ray and a clinical mammography x-ray machine are presented. The various qualities of mammography radiation discussed in this work are in accordance with the IEC 61674 and the AAPM recommendations. This work also presents the methodology and the procedures to maintain and to disseminate the traceability at the x-ray mammography range, describing the interlaboratory comparison performed at LNMRI/IRD/CNEN and at the IPEN/CNEN using the secondary standard ionization chambers traceable with the international standard. It assesses the inter-laboratory comparison consistency and decides whether a questionable value should or not be accepted, using the residual method. This thesis discusses the uncertainties involved in all steps of the calibration chain in accord once with the ISO recommendations. (author)

  18. Dynamic helical CT mammography of breast cancer

    International Nuclear Information System (INIS)

    Yamamoto, Akira; Fukushima, Hitoshi; Okamura, Ryuji; Nakamura, Yoshiaki; Morimoto, Taisuke; Urata, Yoji; Mukaihara, Sumio; Hayakawa, Katsumi

    2006-01-01

    The purpose of this study was to determine whether dynamic helical computed tomography (CT)-mammography could assist in selecting the most appropriate surgical method in women with breast cancer. Preoperative contrast-enhanced helical CT scanning of the breast was performed on 133 female patients with suspicion of breast cancer at the same time as clinical, mammographic, and/or ultrasonographic examinations. The patients were scanned in the prone position with a specially designed CT-compatible device. A helical scan was made with rapid intravenous bolus injection (3 ml/s) of 100 ml of iodine contrast material. Three-dimensional maximum intensity projection (MIP) images were reconstructed, and CT findings were correlated with surgical and histopathological findings. Histopathological analysis revealed 84 malignant lesions and seven benign lesions. The sensitivity, specificity, and accuracy levels of the CT scanning were 94.6%, 58.6%, and 78.9%. Helical scanning alone revealed additional contralateral carcinomas in three of four patients and additional ipsilateral carcinomas in three of five patients. However, the technique gave false-positive readings in 24 patients. The preoperative CT-mammogram altered the surgical method in six patients. Dynamic helical CT-mammography in the prone position may be one of the choices of adjunct imaging in patients with suspected breast cancer scheduled for surgery. (author)

  19. Mammography screening credit card and compliance.

    Science.gov (United States)

    Schapira, D V; Kumar, N B; Clark, R A; Yag, C

    1992-07-15

    Screening for breast cancer using mammography has been shown to be effective in reducing mortality from breast cancer. The authors attempted to determine if use of a wallet-size plastic screening "credit" card would increase participants' compliance for subsequent mammograms when compared with traditional methods of increasing compliance. Two hundred and twenty consecutive women, ages 40-70 years, undergoing their first screening mammography were recruited and assigned randomly to four groups receiving (1) a reminder plastic credit card (2) reminder credit card with written reminder; (3) appointment card; and (4) verbal recommendation. Return rates of the four groups were determined after 15 months. The return rate for subsequent mammograms was significantly higher for participants (72.4%) using the credit card than for participants (39.8%) exposed to traditional encouragement/reminders (P less than 0.0001). The credit card was designed to show the participant's screening anniversary, and the durability of the card may have been a factor in increasing the return rate. The use of reminder credit cards may increase compliance for periodic screening examinations for other cancers and other chronic diseases.

  20. Classification of breast microcalcifications using spectral mammography

    Science.gov (United States)

    Ghammraoui, B.; Glick, S. J.

    2017-03-01

    Purpose: To investigate the potential of spectral mammography to distinguish between type I calcifications, consisting of calcium oxalate dihydrate or weddellite compounds that are more often associated with benign lesions, and type II calcifications containing hydroxyapatite which are predominantly associated with malignant tumors. Methods: Using a ray tracing algorithm, we simulated the total number of x-ray photons recorded by the detector at one pixel from a single pencil-beam projection through a breast of 50/50 (adipose/glandular) tissues with inserted microcalcifications of different types and sizes. Material decomposition using two energy bins was then applied to characterize the simulated calcifications into hydroxyapatite and weddellite using maximumlikelihood estimation, taking into account the polychromatic source, the detector response function and the energy dependent attenuation. Results: Simulation tests were carried out for different doses and calcification sizes for multiple realizations. The results were summarized using receiver operating characteristic (ROC) analysis with the area under the curve (AUC) taken as an overall indicator of discrimination performance and showing high AUC values up to 0.99. Conclusion: Our simulation results obtained for a uniform breast imaging phantom indicate that spectral mammography using two energy bins has the potential to be used as a non-invasive method for discrimination between type I and type II microcalcifications to improve early breast cancer diagnosis and reduce the number of unnecessary breast biopsies.

  1. Annotation of Regular Polysemy

    DEFF Research Database (Denmark)

    Martinez Alonso, Hector

    Regular polysemy has received a lot of attention from the theory of lexical semantics and from computational linguistics. However, there is no consensus on how to represent the sense of underspecified examples at the token level, namely when annotating or disambiguating senses of metonymic words...... and metonymic. We have conducted an analysis in English, Danish and Spanish. Later on, we have tried to replicate the human judgments by means of unsupervised and semi-supervised sense prediction. The automatic sense-prediction systems have been unable to find empiric evidence for the underspecified sense, even...

  2. Regularity of Minimal Surfaces

    CERN Document Server

    Dierkes, Ulrich; Tromba, Anthony J; Kuster, Albrecht

    2010-01-01

    "Regularity of Minimal Surfaces" begins with a survey of minimal surfaces with free boundaries. Following this, the basic results concerning the boundary behaviour of minimal surfaces and H-surfaces with fixed or free boundaries are studied. In particular, the asymptotic expansions at interior and boundary branch points are derived, leading to general Gauss-Bonnet formulas. Furthermore, gradient estimates and asymptotic expansions for minimal surfaces with only piecewise smooth boundaries are obtained. One of the main features of free boundary value problems for minimal surfaces is t

  3. Regularities of radiation heredity

    International Nuclear Information System (INIS)

    Skakov, M.K.; Melikhov, V.D.

    2001-01-01

    One analyzed regularities of radiation heredity in metals and alloys. One made conclusion about thermodynamically irreversible changes in structure of materials under irradiation. One offers possible ways of heredity transmittance of radiation effects at high-temperature transformations in the materials. Phenomenon of radiation heredity may be turned to practical use to control structure of liquid metal and, respectively, structure of ingot via preliminary radiation treatment of charge. Concentration microheterogeneities in material defect structure induced by preliminary irradiation represent the genetic factor of radiation heredity [ru

  4. Influence of age and menstrual cycle on mammography and MR imaging of the breast; Einfluss von Alter und Menstruationszyklus auf Mammographie und MR-Mammographie

    Energy Technology Data Exchange (ETDEWEB)

    Mueller-Schimpfle, M.; Ohmenhaeuser, K.; Claussen, C.D. [Tuebingen Univ. (Germany). Abt. fuer Radiologische Diagnostik

    1997-09-01

    Age and menstrual cycle have an important influence on the breast. This well-known fact is experienced in the daily routine of gynecologists and radiologists. The number of publications addressing the effect of these influences on imaging, however, is surprisingly low. The aim of this work is to describe the influences of age and menstrual cycle on the breast and to address their clinical relevance for mammography and MR mammography. Therefore, own data are presented concerning the age and menstrual cycle influences on breast parenchyma in dynamic MR mammography. Literature data are used to correlate mammography and MR imaging findings with these influences. The changes of the breast due to age and menstrual cycle have important direct implications on performing and reading conventional mammography and MR mammography. The knowledge of these changes is also helpful in the interpretation of findings when comparing different methods. Finally, the data gained by using imaging methods enable important basic insights into physiology and physiopathology of the breast in vivo. (orig.) [Deutsch] Alter und Menstruationszyklus stellen wichtige Einflussfaktoren auf die Mamma dar. Diese Tatsache ist klinisch lange bekannt und im Alltag des Gynaekologen wie Radiologen staendig praesent. Dagegen ist die Anzahl der Publikationen zu den Auswirkungen dieser Einfluesse auf die Bildgebung erstaunlich niedrig. Ziel dieser Arbeit ist es, die alters- und zyklusabhaengigen Veraenderungen der Mamma und deren klinische Relevanz fuer die Mammographie und MR-Mammographie darzustellen. Zu diesem Zweck werden aus einer eigenen Studie Daten der dynamischen MR-Tomographie zum Alters- und Zykluseinfluss auf das Mammaparenchym praesentiert. Darueber hinaus werden diese Einflussfaktoren mit mammographischen und MR-tomographischen Daten aus der Literatur korreliert. Dabei zeigt sich, dass sich aus den alters- und menstruationszyklusbedingten Veraenderungen der Brust wichtige unmittelbare

  5. [Commentary on the planned restructuring of mammography screening in Austria].

    Science.gov (United States)

    Vutuc, Christian; Haidinger, Gerald

    2011-08-01

    With regards to the planned reorganisation of screening mammography in Austria - from an opportunistic to an organised system - the problems related with such a change are depicted from an epidemiological point of view. We were able to demonstrate earlier that opportunistic screening mammography matches the results of controlled screening mammography in Finland and Sweden. Switching to a controlled system in Austria would - besides the need for a change in legislation - lead to enormous expenditures in terms of resources needed and moreover, it could be not evaluated for years.

  6. Digital mammography and their developments; Digitale Mammografie und ihre Weiterentwicklung

    Energy Technology Data Exchange (ETDEWEB)

    Wienbeck, Susanne [Universitaetsmedizin Goettingen (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie; Fischer, Uwe [Diagnostisches Brustzentrum Goettingen (Germany)

    2015-09-15

    At the present time digital mammography is a satisfactory breast diagnostic imaging in clinical as well as screening mammography in defined age groups. Nevertheless it shows beside the application of ionizing radiation in women with dense breasts limitations in the detection of non calcification breast cancers. Tomosynthesis, digital contrast-enhanced mammography and breast-CT with or without contrast media lead to better results. Especially the application of contrast media for the visualisation of the tumor angiogenesis is invariably superior to all other non-contrast imaging modalities. However, the excellent results of breast MRI will be probably accessible with none of the new procedures.

  7. Pain during mammography: Implications for breast screening programmes

    International Nuclear Information System (INIS)

    Andrews, F.J.

    2001-01-01

    Pain experienced during mammography can deter women from attending for breast cancer screening. Review of the current literature on pain experienced during mammography reveals three main areas of interest: reports of the frequency of pain, identification of predictors of pain and strategies for responding to pain. Implications of this literature for breast screening programmes include the need for appropriate measurements of pain during mammography that are valid for screening populations, a further understanding of organizational factors involved in screening programmes that may be predictors of pain and for the development of valid strategies for responding to pain within breast screening programmes. Copyright (2001) Blackwell Science Pty Ltd

  8. Studies Comparing Screen-Film Mammography and Full-Field Digital Mammography in Breast Cancer Screening: Updated Review

    International Nuclear Information System (INIS)

    Skaane, P.

    2009-01-01

    Full-field digital mammography (FFDM) has several potential benefits as compared with screen-film mammography (SFM) in mammography screening. Digital technology also opens for implementation of advanced applications, including computer-aided detection (CAD) and tomosynthesis. Phantom studies and experimental clinical studies have shown that FFDM is equal or slightly superior to SFM for detection and characterization of mammographic abnormalities. Despite obvious advantages, the conversion to digital mammography has been slower than anticipated, and not only due to higher costs. Until very recently, some countries did not even permit the use of digital mammography in breast cancer screening. The reason for this reluctant attitude was concern about lower spatial resolution and about using soft-copy reading. Furthermore, there was a lack of data supporting improved diagnostic accuracy using FFDM in a screening setting, since two pioneer trials both showed nonsignificantly lower cancer detection rate at FFDM. The 10 studies comparing FFDM and SFM in mammography screening published so far have shown divergent and rather conflicting results. Nevertheless, there is a rapid conversion to digital mammography in breast cancer screening in many western countries. The aim of this article is to give an updated review of these studies, discuss the conflicting findings, and draw some conclusions from the results

  9. Breast cancer screening: Evidence of the effect of adjunct ultrasound screening in women with unilateral mammography-negative dense breasts

    Directory of Open Access Journals (Sweden)

    Atoosa Adibi

    2015-01-01

    Full Text Available Background: Patients with the previous history of breast cancer are in risk of contralateral breast cancer. On the other hand, increased breast density is a risk factor for breast cancer and the sensitivity of detecting nonpalpable cancers in screening mammography in radiographically dense breasts is low. The use of ultrasonography in dense breast remains a controversial topic. The purpose of this study was to assess the usefulness of routine ultrasonography in follow-up of women with the previous history of breast cancer and negative mammography but dense breasts. Materials and Methods: In a cross-sectional study, a total of 267 individuals with unilateral postmastectomy mammogram screened and 153 subjects assigned to study. There were 28 subjects with American College of Radiology (ACR breast density 2 and 125 with ACR breast density 3-4, which there was no new finding in their mammogram in comparison to previous studies. We assumed subjects with ACR breast density 3-4 as mammographic Breast Imaging Reporting and Data System (BI-RADS category 0 for malignancy. Standard two-view mammogram was performed for all participants, and breast ultrasound (US examinations were performed by an expert radiologist in radial and anti-radial planes. The data were analyzed using SPSS version 20.0 (SPSS Inc., Chicago, Illinois, USA. Results: The results showed that in subjects with ACR breast density 3-4, when there was no new density in two consecutive mammograms in comparison to previous studies, US also showed no possibility for malignancy (BI-RADS 1-2. And also in subjects with ACR breast density 2, when the mammographic results were BI-RADS 1-2, the US results was the same. Conclusion: Our data indicate that for the detection of breast cancer, sensitivity of US was not greater than mammography in patients with postmastectomy unilateral dense breast if there is not any new density.

  10. Maintenance: Two Views.

    Science.gov (United States)

    Ballard, J. Barry; Burdette, Clarence E.

    1987-01-01

    Presents two viewpoints on the question of using funding from the Vocational Education Act to maintain ongoing vocational programs. Ballard argues that programs have improved qualitatively because of additional program improvement monies, whereas Burdette argues that the ban on using funds for maintenance treats some states unfairly. (CH)

  11. Two Views of Prayer

    NARCIS (Netherlands)

    Sarot, Marcel; Mühling, Markus

    2016-01-01

    Marcel Sarot vergleicht eine katholische mit einer evangelischen Konzeption der Theologie des Gebets. Evangelische und katholische Christinnen und Christen können coneinander lernen. In der katholische Konzeption wird v.a. die christliche Gemeinschaft hervorgehoben. In der evngaelischen Konzeption

  12. Comparison of digital mammography alone and digital mammography plus tomosynthesis in a population-based screening program.

    Science.gov (United States)

    Skaane, Per; Bandos, Andriy I; Gullien, Randi; Eben, Ellen B; Ekseth, Ulrika; Haakenaasen, Unni; Izadi, Mina; Jebsen, Ingvild N; Jahr, Gunnar; Krager, Mona; Niklason, Loren T; Hofvind, Solveig; Gur, David

    2013-04-01

    To assess cancer detection rates, false-positive rates before arbitration, positive predictive values for women recalled after arbitration, and the type of cancers detected with use of digital mammography alone and combined with tomosynthesis in a large prospective screening trial. A prospective, reader- and modality-balanced screening study of participants undergoing combined mammography plus tomosynthesis, the results of which were read independently by four different radiologists, is under way. The study was approved by a regional ethics committee, and all participants provided written informed consent. The authors performed a preplanned interim analysis of results from 12,631 examinations interpreted by using mammography alone and mammography plus tomosynthesis from November 22, 2010, to December 31, 2011. Analyses were based on marginal log-linear models for binary data, accounting for correlated interpretations and adjusting for reader-specific performance levels by using a two-sided significance level of .0294. Detection rates, including those for invasive and in situ cancers, were 6.1 per 1000 examinations for mammography alone and 8.0 per 1000 examinations for mammography plus tomosynthesis (27% increase, adjusted for reader; P = .001). False-positive rates before arbitration were 61.1 per 1000 examinations with mammography alone and 53.1 per 1000 examinations with mammography plus tomosynthesis (15% decrease, adjusted for reader; P tomosynthesis; P = .72). Twenty-five additional invasive cancers were detected with mammography plus tomosynthesis (40% increase, adjusted for reader; P tomosynthesis (P tomosynthesis in a screening environment resulted in a significantly higher cancer detection rate and enabled the detection of more invasive cancers. Clinical trial registration no. NCT01248546. RSNA, 2013

  13. Breast imaging and reporting data system - Mammography. ACR BI-RADS registered -Mammography

    International Nuclear Information System (INIS)

    Fischer, U.; Helbrich, T.

    2006-01-01

    ACR BI-RADS registered mammography is an established technique in all German-speaking countries and has become a standard part of all mammographic findings. The first German-language edition three years ago made a significant contribution to this. This is the second, revised and edited edition. It is based on the fourth English-language edition of the ACR which was published in 2003. (orig.)

  14. The clinical use of mammography in the male; Klinische Relevanz der Mammographie beim Mann

    Energy Technology Data Exchange (ETDEWEB)

    Merkle, E [Ulm Univ. (Germany). Abt. Radiologie; Mueller, M [Ulm Univ. (Germany). Abt. Radiologie; Vogel, J [Ulm Univ. (Germany). Abt. Radiologie; Klatt, S [Ulm Univ. (Germany). Abt. Innere Medizin I; Goerich, J [Ulm Univ. (Germany). Abt. Radiologie; Berger, H G [Ulm Univ. (Germany). Allgemeinchirurgische Abt.; Brambs, H J [Ulm Univ. (Germany). Abt. Radiologie

    1996-01-01

    During a period of four years 104 mammograms were performed in 89 men. Mastectomies were carried out on 23 men (group 1). 66 patients (group 2) were followed up clinically and in 15 patients serial mammograms were obtained. In group 1 there were 5 patients with bilateral gynaecomastia, 9 with unilateral gynaecomastia and two with pseudogynaecomastia and there were 7 patients with malignancies. In group 2 there were 46 patients with bilateral gynaecomastia and 10 patients with unilateral gynaecomastia. Pseudogynaecomastia was found in 25 patients. There were 7 malignancies, of which 5 had been suspected clinically and one had been diagnosed as gynaecomastia by mammography. Two carcinomas in situ were missed clinically and also by mammography. When malignancy is not suspected on clinical grounds the first examination should be sonography. Where, however, malignancy is suspected, and for follow-up, mammography retains its primary position. (orig./MG) [Deutsch] In einem 4-Jahres-Zeitraum wurden bei 89 Maennern insgesamt 104 Mammogramme angefertigt. 23 Maenner (=Gruppe 1) wurden mastektomiert. 66 Patienten (=Gruppe 2) wurden klinisch und zum Teil mammographisch kontrolliert. Alle Mammogramme wurden in Unkenntnis des klinischen Befundes retrospektiv ausgewertet und, wenn moeglich, dem histologischen Ergebnis gegenuebergestellt. In der Gruppe 1 fand sich eine beidseitige Gynaekomastie in 5/23 Faellen, eine einseitige Form in 9/23 Faellen, eine Pseudogynaekomastie in 2/23 Faellen und ein Malignom in 7/23 Faellen. In Gruppe 2 ergab sich eine beidseitige Gynaekomastie in 46/81 Faellen gegenueber einer einseitigen Form in 10/81 Faellen. Eine Pseudogynaekomastie fand sich in 25/81 Faellen. Von 7 Malignomen waren 5 klinisch suspekt, wobei eines mammographisch als Gynaekomastie imponierte. Zwei In-situ-Karzinome waren sowohl mammographisch als auch klinisch okkult. Klinisch nicht malignomsuspekte Befunde sollten primaer der Mammasonographie zugefuehrt werden. Bei

  15. Quality control methodology and implementation of X-radiation standards beams, mammography level, following the standard IEC 61267

    International Nuclear Information System (INIS)

    Correa, Eduardo de Lima

    2010-01-01

    In this work it was developed and applied a quality control program of the X radiation system (160 kV, constant potential, target of tungsten) of the Calibration Laboratory of IPEN(LCI) in the energy range relative to mammography beams (from 25 kV to 35 kV). The X radiation standards beams, level mammography, using molybdenum and aluminum as additional filtration, were established after the application of this quality control program following national and international recommendations. The reference ionization chamber has traceability to PTB and was regularly submitted to quality control tests for evaluation and analysis of its performance. The radiation qualities emerging from the X-radiation assembly (RQR-M), based on a phantom made up of an aluminum added filter (RQA-M), narrow beam condition (RQN-M) and broad beam condition (RQB-M), following the recommendations of the international standard IEC 61267 (2005) and the IAEA code of practice, TRS 457 (2007) were established. For the implantation of RQN-M and RQB-M radiation qualities, two mammography phantoms were developed. The half-value layers found are those presented by the German primary laboratory PTB, and varied from 0.35 to 1.21 mm Al. The air kerma rates were obtained for all the 15 implanted qualities. (author)

  16. Malignancy Detection on Mammography Using Dual Deep Convolutional Neural Networks and Genetically Discovered False Color Input Enhancement.

    Science.gov (United States)

    Teare, Philip; Fishman, Michael; Benzaquen, Oshra; Toledano, Eyal; Elnekave, Eldad

    2017-08-01

    Breast cancer is the most prevalent malignancy in the US and the third highest cause of cancer-related mortality worldwide. Regular mammography screening has been attributed with doubling the rate of early cancer detection over the past three decades, yet estimates of mammographic accuracy in the hands of experienced radiologists remain suboptimal with sensitivity ranging from 62 to 87% and specificity from 75 to 91%. Advances in machine learning (ML) in recent years have demonstrated capabilities of image analysis which often surpass those of human observers. Here we present two novel techniques to address inherent challenges in the application of ML to the domain of mammography. We describe the use of genetic search of image enhancement methods, leading us to the use of a novel form of false color enhancement through contrast limited adaptive histogram equalization (CLAHE), as a method to optimize mammographic feature representation. We also utilize dual deep convolutional neural networks at different scales, for classification of full mammogram images and derivative patches combined with a random forest gating network as a novel architectural solution capable of discerning malignancy with a specificity of 0.91 and a specificity of 0.80. To our knowledge, this represents the first automatic stand-alone mammography malignancy detection algorithm with sensitivity and specificity performance similar to that of expert radiologists.

  17. 2-D or 3-D Mammography?: The Future of Breast Cancer Detection | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... Future of Breast Cancer Detection Follow us 2-D or 3-D Mammography?: The Future of Breast Cancer Detection NIH- ... will test two types of imaging tools—2-D and 3-D mammography. 2-D mammography takes ...

  18. Object characterization simulator for estimating compressed breast during mammography

    International Nuclear Information System (INIS)

    Pinheiro, Luciana de J.S.; Rio, Margarita Chevalier del

    2011-01-01

    The measurement of the thickness of a compressed breast during the mammography test is necessary in order to calculate the glandular dose in mammography procedures, in an analysis of risk/benefit, given that the target organ in these procedures is highly sensitive to ionising radiation. However, mammography is a test of utmost importance in diagnosis. In theory, it may be possible to calculate the thickness of the compressed breast through the measurements of the focus object distance by using projections of radio opaque objects fixed to the compression tray. The facilities of the Laboratory of Applied Radioprotection to Mammography - LARAM were used for this study, as well as breast simulators with well defined thickness, in the assembly of the techniques for the measurement of the thickness of the compressed breast. The results showed that it is possible to determine this thickness through calculations and simulators through this method which is susceptible to be adequate to the dosimetry. (author)

  19. Understanding women's mammography intentions: a theory-based investigation.

    Science.gov (United States)

    Naito, Mikako; O'Callaghan, Frances V; Morrissey, Shirley

    2009-01-01

    The present study compared the utility of two models (the Theory of Planned Behavior and Protection Motivation Theory) in identifying factors associated with intentions to undertake screening mammography, before and after an intervention. The comparison was made between the unique components of the two models. The effect of including implementation intentions was also investigated. Two hundred and fifty-one women aged 37 to 69 years completed questionnaires at baseline and following the delivery of a standard (control) or a protection motivation theory-based informational intervention. Hierarchical multiple regressions indicated that theory of planned behavior variables were associated with mammography intentions. Results also showed that inclusion of implementation intention in the model significantly increased the association with mammography intentions. The findings suggest that future interventions aiming to increase screening mammography participation should focus on the theory of planned behavior variables and that implementation intention should also be targeted.

  20. Ultrasonography as a diagnostic method in addition to mammography

    Energy Technology Data Exchange (ETDEWEB)

    Otto, H.; Roer, E.

    1988-05-01

    By using ultrasonography in addition to mammography, experienced diagnosticians essentially enhance the safety of their diagnosis of mammary gland diseases. The same applies to gynecomastia, the condition after plastic surgery, and mastitis.

  1. Establishment of Guidance Levels in General Radiography and Mammography

    International Nuclear Information System (INIS)

    2010-04-01

    Coordinated project report IAEA ARCAL LXXV-RLA/9/048 Pilot Exercise for Developing and Setting Levels Reference in General Radiography and Mammography as a Tool for Optimizing Radiation Protection and Reduce Patient Exposure in Latin America

  2. [Hierarchy structuring for mammography technique by interpretive structural modeling method].

    Science.gov (United States)

    Kudo, Nozomi; Kurowarabi, Kunio; Terashita, Takayoshi; Nishimoto, Naoki; Ogasawara, Katsuhiko

    2009-10-20

    Participation in screening mammography is currently desired in Japan because of the increase in breast cancer morbidity. However, the pain and discomfort of mammography is recognized as a significant deterrent for women considering this examination. Thus quick procedures, sufficient experience, and advanced skills are required for radiologic technologists. The aim of this study was to make the point of imaging techniques explicit and to help understand the complicated procedure. We interviewed 3 technologists who were highly skilled in mammography, and 14 factors were retrieved by using brainstorming and the KJ method. We then applied Interpretive Structural Modeling (ISM) to the factors and developed a hierarchical concept structure. The result showed a six-layer hierarchy whose top node was explanation of the entire procedure on mammography. Male technologists were related to as a negative factor. Factors concerned with explanation were at the upper node. We gave attention to X-ray techniques and considerations. The findings will help beginners improve their skills.

  3. The Influence of Spiritual Framing on African American Women's Mammography Intentions: A Randomized Trial.

    Science.gov (United States)

    Best, Alicia L; Spencer, S Melinda; Friedman, Daniela B; Hall, Ingrid J; Billings, Deborah

    2016-06-01

    Spiritual framing of breast cancer communication may provide a useful strategy for addressing disparate rates of breast cancer mortality among African American women. The efficacy of a spiritually framed breast cancer screening (BCS) message was compared with that of a traditional BCS message. Specifically, 200 African American women were randomly assigned to review either a spiritually framed or traditional BCS message and complete a self-administered survey, including a thought-listing form. Message efficacy was measured by number of thoughts generated (elaboration), ratio of positive to negative thoughts (polarity), and intention to obtain and/or recommend a mammogram. Multiple linear regression and structural equation modeling were used to assess direct and indirect (mediated) associations among variables. Spiritual framing was positively associated with greater elaboration (β = .265, SE = .36, p framing also had a significant indirect effect on mammography intentions through polarity (standardized indirect effect = .057, 95% confidence interval [.024, .106], p framing may improve the efficacy of BCS messages among African American women by eliciting more positive thoughts about screening. Interventions targeting African American women might consider the role of spirituality when tailoring messages to encourage regular mammography use.

  4. Eight years of quality control in Bulgaria: impact on mammography practice.

    Science.gov (United States)

    Avramova-Cholakova, S; Lilkov, G; Kaneva, M; Terziev, K; Nakov, I; Mutkurov, N; Kovacheva, D; Ivanova, M; Vasilev, D

    2015-07-01

    The requirements for quality control (QC) in diagnostic radiology were introduced in Bulgarian legislation in 2005. Hospital medical physicists and several private medical physics groups provide QC services to radiology departments. The aim of this study was to analyse data from QC tests in mammography and to investigate the impact of QC introduction on mammography practice in the country. The study was coordinated by the National Centre of Radiobiology and Radiation Protection. All medical physics services were requested to fill in standardised forms with information about most important parameters routinely measured during QC. All QC service providers responded. Results demonstrated significant improvement of practice since the introduction of QC, with reduction of established deviations from 65 % during the first year to 7 % in the last year. The systems that do not meet the acceptability criteria were suspended from use. Performance of automatic exposure control and digital detectors are not regularly tested because of the absence of requirements in the legislation. The need of updated guidance and training of medical physicists to reflect the change in technology was demonstrated. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. The Role of Effective Communication to Enhance Participation in Screening Mammography: A New Zealand Case

    Directory of Open Access Journals (Sweden)

    Margaret A. Brunton

    2009-02-01

    Full Text Available Changes in the organisation of health care have dominated policy initiatives over the past two decades in many countries. An increasing reliance on public health initiatives to prevent or detect disease early has resulted in an increase in programs that screen for cancer in the community. In turn, this accentuates the need to persuasively communicate the value of such initiatives to encourage continued participation. Merely placing screening programs into a community setting is not sufficient to ensure that adequate numbers will voluntarily participate regularly to achieve anticipated cost and mortality savings in the population. In this research the influence of managing communication in a public screening mammography program was investigated. The results revealed that significant opportunities were overlooked for reassurance and information during the physical mammography process. In turn, this highlights the influence of constraints imposed by the structure of the screening program and the resources allocated to the process. This research suggests that it is important to address multiple influences, including ethnic differences, when asking questions about the effectiveness of public health policy, particularly when considering the choices women make about ongoing participation in breast screening programs.

  6. Effective field theory dimensional regularization

    International Nuclear Information System (INIS)

    Lehmann, Dirk; Prezeau, Gary

    2002-01-01

    A Lorentz-covariant regularization scheme for effective field theories with an arbitrary number of propagating heavy and light particles is given. This regularization scheme leaves the low-energy analytic structure of Greens functions intact and preserves all the symmetries of the underlying Lagrangian. The power divergences of regularized loop integrals are controlled by the low-energy kinematic variables. Simple diagrammatic rules are derived for the regularization of arbitrary one-loop graphs and the generalization to higher loops is discussed

  7. Effective field theory dimensional regularization

    Science.gov (United States)

    Lehmann, Dirk; Prézeau, Gary

    2002-01-01

    A Lorentz-covariant regularization scheme for effective field theories with an arbitrary number of propagating heavy and light particles is given. This regularization scheme leaves the low-energy analytic structure of Greens functions intact and preserves all the symmetries of the underlying Lagrangian. The power divergences of regularized loop integrals are controlled by the low-energy kinematic variables. Simple diagrammatic rules are derived for the regularization of arbitrary one-loop graphs and the generalization to higher loops is discussed.

  8. Abnormality Detection in Mammography using Deep Convolutional Neural Networks

    OpenAIRE

    Xi, Pengcheng; Shu, Chang; Goubran, Rafik

    2018-01-01

    Breast cancer is the most common cancer in women worldwide. The most common screening technology is mammography. To reduce the cost and workload of radiologists, we propose a computer aided detection approach for classifying and localizing calcifications and masses in mammogram images. To improve on conventional approaches, we apply deep convolutional neural networks (CNN) for automatic feature learning and classifier building. In computer-aided mammography, deep CNN classifiers cannot be tra...

  9. Postmortem validation of breast density using dual-energy mammography

    OpenAIRE

    Molloi, Sabee; Ducote, Justin L.; Ding, Huanjun; Feig, Stephen A.

    2014-01-01

    Purpose: Mammographic density has been shown to be an indicator of breast cancer risk and also reduces the sensitivity of screening mammography. Currently, there is no accepted standard for measuring breast density. Dual energy mammography has been proposed as a technique for accurate measurement of breast density. The purpose of this study is to validate its accuracy in postmortem breasts and compare it with other existing techniques. Methods: Forty postmortem breasts were imaged using a dua...

  10. Potential Cost Savings of Contrast-Enhanced Digital Mammography.

    Science.gov (United States)

    Patel, Bhavika K; Gray, Richard J; Pockaj, Barbara A

    2017-06-01

    The purpose of this article is to discuss whether the sensitivity and specificity of contrast-enhanced digital mammography (CEDM) render it a viable diagnostic alternative to breast MRI. That CEDM couples low-energy images (comparable to the diagnostic quality of standard mammography) and subtracted contrast-enhanced mammograms make it a cost-effective modality and a realistic substitute for the more costly breast MRI.

  11. Dual-energy contrast-enhanced spectral mammography (CESM).

    Science.gov (United States)

    Daniaux, Martin; De Zordo, Tobias; Santner, Wolfram; Amort, Birgit; Koppelstätter, Florian; Jaschke, Werner; Dromain, Clarisse; Oberaigner, Willi; Hubalek, Michael; Marth, Christian

    2015-10-01

    Dual-energy contrast-enhanced mammography is one of the latest developments in breast care. Imaging with contrast agents in breast cancer was already known from previous magnetic resonance imaging and computed tomography studies. However, high costs, limited availability-or high radiation dose-led to the development of contrast-enhanced spectral mammography (CESM). We reviewed the current literature, present our experience, discuss the advantages and drawbacks of CESM and look at the future of this innovative technique.

  12. [Fine needle aspiration cytology of mammography screening

    DEFF Research Database (Denmark)

    Engvad, B.; Laenkholm, A.V.; Schwartz, Thue W.

    2009-01-01

    INTRODUCTION: In the year 2000 a quality assurance programme for the preoperative breast diagnostics was introduced in Denmark. The programme was based on the "European guidelines for quality assurance in breast cancer screening and diagnosis" where - among other measures - five cytological......-choice treatment. MATERIAL AND METHODS: 767 women had FNAC performed from a total of 783 lesions at the Mammography Clinic, University Hospital Odense. All FNACs were compared with the final histology diagnosis. Nine statistical parameters were calculated according to the European guidelines. RESULTS: A total...... of 66% of the 783 FNACs had a malignant cytology diagnosis, which in 99% of the cases turned out to be the correct diagnosis. Four lesions were false positives all of which represented benign proliferative breast diseases. The surgical procedures in these cases were either excisional biopsy...

  13. Hexagonal wavelet processing of digital mammography

    Science.gov (United States)

    Laine, Andrew F.; Schuler, Sergio; Huda, Walter; Honeyman-Buck, Janice C.; Steinbach, Barbara G.

    1993-09-01

    This paper introduces a novel approach for accomplishing mammographic feature analysis through overcomplete multiresolution representations. We show that efficient representations may be identified from digital mammograms and used to enhance features of importance to mammography within a continuum of scale-space. We present a method of contrast enhancement based on an overcomplete, non-separable multiscale representation: the hexagonal wavelet transform. Mammograms are reconstructed from transform coefficients modified at one or more levels by local and global non-linear operators. Multiscale edges identified within distinct levels of transform space provide local support for enhancement. We demonstrate that features extracted from multiresolution representations can provide an adaptive mechanism for accomplishing local contrast enhancement. We suggest that multiscale detection and local enhancement of singularities may be effectively employed for the visualization of breast pathology without excessive noise amplification.

  14. Instrumentation optimization for positron emission mammography

    International Nuclear Information System (INIS)

    Moses, William W.; Qi, Jinyi

    2003-01-01

    The past several years have seen designs for PET cameras optimized to image the breast, commonly known as Positron Emission Mammography or PEM cameras. The guiding principal behind PEM instrumentation is that a camera whose field of view is restricted to a single breast has higher performance and lower cost than a conventional PET camera. The most common geometry is a pair of parallel planes of detector modules, although geometries that encircle the breast have also been proposed. The ability of the detector modules to measure the depth of interaction (DOI) is also a relevant feature. This paper finds that while both the additional solid angle coverage afforded by encircling the breast and the decreased blurring afforded by the DOI measurement improve performance, the ability to measure DOI is more important than the ability to encircle the breast

  15. Patient dose and risk in mammography

    International Nuclear Information System (INIS)

    Law, J.

    1991-01-01

    Patient dose in mammography is estimated by two methods compared and giving agreement. A mean tissue dose of about 1 mGy per film is found for a breast of 4.5 cm compressed thickness. Variables affecting dose are then considered quantitatively, including compressed breast thickness, tube potential, grids, magnification and beam collimation. The variables having the greatest effect are breast thickness and magnification. The dose estimates are combined with existing data on breast cancer induction to predict the risk of carcinogenesis in a breast screening programme. For example, in a screening centre performing 15 000 examinations per year, only one induced cancer is predicted in about 7 years of screening under average UK conditions of age and breast thickness. (author)

  16. Fundamental limits of positron emission mammography

    International Nuclear Information System (INIS)

    Moses, William W.; Qi, Jinyi

    2001-01-01

    We explore the causes of performance limitation in positron emission mammography cameras. We compare two basic camera geometries containing the same volume of 511 keV photon detectors, one with a parallel plane geometry and another with a rectangular geometry. We find that both geometries have similar performance for the phantom imaged (in Monte Carlo simulation), even though the solid angle coverage of the rectangular camera is about 50 percent higher than the parallel plane camera. The reconstruction algorithm used significantly affects the resulting image; iterative methods significantly outperform the commonly used focal plane tomography. Finally, the characteristics of the tumor itself, specifically the absolute amount of radiotracer taken up by the tumor, will significantly affect the imaging performance

  17. Screening for breast cancer with mammography

    DEFF Research Database (Denmark)

    Gøtzsche, Peter C; Nielsen, Margrethe

    2009-01-01

    BACKGROUND: A variety of estimates of the benefits and harms of mammographic screening for breast cancer have been published and national policies vary. OBJECTIVES: To assess the effect of screening for breast cancer with mammography on mortality and morbidity. SEARCH STRATEGY: We searched Pub...... excluded a biased trial and included 600,000 women in the analyses. Three trials with adequate randomisation did not show a significant reduction in breast cancer mortality at 13 years (relative risk (RR) 0.90, 95% confidence interval (CI) 0.79 to 1.02); four trials with suboptimal randomisation showed...... a significant reduction in breast cancer mortality with an RR of 0.75 (95% CI 0.67 to 0.83). The RR for all seven trials combined was 0.81 (95% CI 0.74 to 0.87). We found that breast cancer mortality was an unreliable outcome that was biased in favour of screening, mainly because of differential...

  18. 75 FR 76006 - Regular Meeting

    Science.gov (United States)

    2010-12-07

    ... FARM CREDIT SYSTEM INSURANCE CORPORATION Regular Meeting AGENCY: Farm Credit System Insurance Corporation Board. ACTION: Regular meeting. SUMMARY: Notice is hereby given of the regular meeting of the Farm Credit System Insurance Corporation Board (Board). Date and Time: The meeting of the Board will be held...

  19. A study of quality assurance in mammography

    International Nuclear Information System (INIS)

    Briquet, Claudia; Mota, Helvecio C.; Costa, Marcos R.

    1997-01-01

    Full text. Nowadays mammography has two definitive important roles: as a complementary tool to confirm clinical findings and for the detection of early breast cancer. To reach and maintain the standards of image quality within the frontiers of reasonable radiation doses, the facilities must follow a QA program. The objective of this study is to accomplish such a program in three school hospitals in Rio de Janeiro. We made assessment of clinical images using the Accreditation American Phantom and measured the patients skin entrance doses with TLD 100. In each facility we evaluated the technical parameters of the mammographic units using a Victoreen 4000 M+ and an evaluation of the compression devices. The 3 hospitals studied use film and screen Min R Kodak and have Kodak processors, none of them dedicated to mammograms. The tube voltage, measured was not significantly different from the indicated values, the variations were lesser than 5%. In one of the hospitals the kVp did not show reproducibility, the coefficient of variation was too high - 1,02. The same facility showed an exposure time with variation of 7% and we asked for corrective action. Measures of HVL showed the same value for the 3 hospitals the compression were adequate. The patients skin entrance doses were measured with TLD 100 and showed the range 3,25 a 10,26 mGy. This range is due to differences in density and thickness of the breast. The doses values were in accordance with the Quality Criteria for Mammography of the Commission of the European Communities

  20. Photographic and energy spectral evaluation of mammography

    International Nuclear Information System (INIS)

    Chiyasu, Shikibu; Ise, Toshihide; Kato, Isao; Asakawa, Yoshihisa; Nakamae, Haruo

    1980-01-01

    The combination of molybdenium anode X-ray tube (with a beryllium window and 0.03 mm molybdenium filter) and a single high resolution intensifying screen (rare earth phosphors) with a green-sensitive single emulsion film is regarded as a very useful and optimum system for mammography. In order to find the optimum exposure condition in this system that we investigated the transmission properties of the mammographic cassette, the intensifying screen and the specimen of breast. We examined four cassettes by the contrast (0.1/0.5 mm aluminium), the visibility of small particles (Mg 2 SiO 4 , 150 -- 600 mu m diameter) by five observers and dose measurements using mammographic phantom, Kodak Min-R screen and Fuji RX-M film. We measured the transmission photon spectra by using pure germanium detector through tumor and normal glandular tissue of breast cancer (3.5 kg weight, 6.5 cm, thickness and 1.0 cm tumor diameter) after surgery. We examined the relationship between the contrast and the transmission photon spectra of macro-specimen of breast cancer (fixation in 10% folmalin solution). Then we selected the phantom materials for mammography which have the same property as the specimen of cancer in the transmission spectra. From these results, the low tube voltage (25 kV) technique gives high contrast and good visibility of small particles in this system. Also in the system, the smaller X-ray absorption of cassette (or package) gives higher contrast, better visibility and lower dose. For the phantom materials, ABS resin has almost same transmission property as the measured normal glandular tissue and Lucite is almost same as the measured tumor and glandular from the point of transmission spectra. (author)

  1. Selection of regularization parameter for l1-regularized damage detection

    Science.gov (United States)

    Hou, Rongrong; Xia, Yong; Bao, Yuequan; Zhou, Xiaoqing

    2018-06-01

    The l1 regularization technique has been developed for structural health monitoring and damage detection through employing the sparsity condition of structural damage. The regularization parameter, which controls the trade-off between data fidelity and solution size of the regularization problem, exerts a crucial effect on the solution. However, the l1 regularization problem has no closed-form solution, and the regularization parameter is usually selected by experience. This study proposes two strategies of selecting the regularization parameter for the l1-regularized damage detection problem. The first method utilizes the residual and solution norms of the optimization problem and ensures that they are both small. The other method is based on the discrepancy principle, which requires that the variance of the discrepancy between the calculated and measured responses is close to the variance of the measurement noise. The two methods are applied to a cantilever beam and a three-story frame. A range of the regularization parameter, rather than one single value, can be determined. When the regularization parameter in this range is selected, the damage can be accurately identified even for multiple damage scenarios. This range also indicates the sensitivity degree of the damage identification problem to the regularization parameter.

  2. Ensemble manifold regularization.

    Science.gov (United States)

    Geng, Bo; Tao, Dacheng; Xu, Chao; Yang, Linjun; Hua, Xian-Sheng

    2012-06-01

    We propose an automatic approximation of the intrinsic manifold for general semi-supervised learning (SSL) problems. Unfortunately, it is not trivial to define an optimization function to obtain optimal hyperparameters. Usually, cross validation is applied, but it does not necessarily scale up. Other problems derive from the suboptimality incurred by discrete grid search and the overfitting. Therefore, we develop an ensemble manifold regularization (EMR) framework to approximate the intrinsic manifold by combining several initial guesses. Algorithmically, we designed EMR carefully so it 1) learns both the composite manifold and the semi-supervised learner jointly, 2) is fully automatic for learning the intrinsic manifold hyperparameters implicitly, 3) is conditionally optimal for intrinsic manifold approximation under a mild and reasonable assumption, and 4) is scalable for a large number of candidate manifold hyperparameters, from both time and space perspectives. Furthermore, we prove the convergence property of EMR to the deterministic matrix at rate root-n. Extensive experiments over both synthetic and real data sets demonstrate the effectiveness of the proposed framework.

  3. Efficacy of storage phosphor-based digital mammography in diagnosis of breast cancer

    International Nuclear Information System (INIS)

    Kitahama, Hiroyuki

    1991-01-01

    The aim of this study is to present efficacy of storage phosphor-based digital mammography (CR-mammography) in diagnosis of breast cancer. Ninety-seven cases with breast cancer including 44 cases less than 2 cm in macroscopic size (t1 cases) were evaluated using storage phosphor-based digital mammography (2000 x 2510 pixels by 10 bits). Abnormal findings on CR-mammography were detected in 86 cases (88.7%) of 97 women with breast cancer. Sensitivity of CR-mammography was 88.7%. It was superior to that of film-screen mammography. On t1 breast cancer cases, sensitivity on CR-mammography was 88.6%. False negative rate in t1 breast cancer cases was reduced by image processing using CR-mammography. To evaluate microcalcifications, CR-mammograms and film-screen mammograms were investigated in 22 cases of breast cancer proven pathologically the existence of microcalcifications and 11 paraffin tissue blocks of breast cancer. CR-mammography was superior to film-screen mammography in recognizing of microcalcifications. As regards the detectability for the number and the shape of microcalcifications, CR-mammography was equivalent to film-screen mammography. Receiver operating characteristic (ROC) analysis by eight observers was performed for CR-mammography and film-screen mammography with 54 breast cancer patients and 54 normal cases. The detectability of abnormal findings of breast cancer on CR-mammography (ROC area=0.91) was better than that on film-screen mammography (ROC area=0.88) (p<0.05). Efficacy of storage phosphor-based digital mammography in diagnosis of breast cancer was discussed and demonstrated in this study. (author)

  4. Comparative evaluation of average glandular dose and image of digital mammography and film mammography in Minas Gerais, Brazil

    International Nuclear Information System (INIS)

    Nogueira, M.; Leyton, F.; Rodrigue, L. L.C.; Oliveira, M.A.; Joana, G.S.; Silva, S.D.

    2015-01-01

    Breast cancer is the most common cancer among women, and early detection is critical to its diagnosis and treatment. Mammography is the best method for breast-cancer screening and is capable of reducing mortality rates To date, the most effective method for early detection of breast cancer has been x-ray mammography for which the screen/film (SF) technique has been the gold standard. Digital mammography has been proposed as a substitute for film mammography given the benefits inherent to digital technology. The purpose of our study was to compare the technical performance of digital mammographic and screen-film mammography. A PMMA phantom with objects to simulate breast structures. For the screen/film (SF) technique the results showed that 54% mammography units did not achieve the minimum acceptable performance as far the image quality. Besides, 67% services showed inadequate performance in their processing systems, which had significant influence on the image quality. At the mean glandular dose only 44% of digital systems evaluated were compliant in all thicknesses of PMMA. The average glandular dose AGD was 90 % higher than in screen/film systems. (authors)

  5. Effects of a risk-based online mammography intervention on accuracy of perceived risk and mammography intentions.

    Science.gov (United States)

    Seitz, Holli H; Gibson, Laura; Skubisz, Christine; Forquer, Heather; Mello, Susan; Schapira, Marilyn M; Armstrong, Katrina; Cappella, Joseph N

    2016-10-01

    This experiment tested the effects of an individualized risk-based online mammography decision intervention. The intervention employs exemplification theory and the Elaboration Likelihood Model of persuasion to improve the match between breast cancer risk and mammography intentions. 2918 women ages 35-49 were stratified into two levels of 10-year breast cancer risk (<1.5%; ≥1.5%) then randomly assigned to one of eight conditions: two comparison conditions and six risk-based intervention conditions that varied according to a 2 (amount of content: brief vs. extended) x 3 (format: expository vs. untailored exemplar [example case] vs. tailored exemplar) design. Outcomes included mammography intentions and accuracy of perceived breast cancer risk. Risk-based intervention conditions improved the match between objective risk estimates and perceived risk, especially for high-numeracy women with a 10-year breast cancer risk ≤1.5%. For women with a risk≤1.5%, exemplars improved accuracy of perceived risk and all risk-based interventions increased intentions to wait until age 50 to screen. A risk-based mammography intervention improved accuracy of perceived risk and the match between objective risk estimates and mammography intentions. Interventions could be applied in online or clinical settings to help women understand risk and make mammography decisions. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. Automated texture scoring for assessing breast cancer masking risk in full field digital mammography

    DEFF Research Database (Denmark)

    Kallenberg, Michiel Gijsbertus J; Petersen, Peter Kersten; Lillholm, Martin

    2015-01-01

    of cancerous tissue, we took the contralateral mammograms. We developed a novel machine learning based method called convolutional sparse autoencoder (CSAE) to characterize mammographic texture. The CSAE was trained and tested on raw mammograms to separate interval cancers from controls in a five-fold cross......PURPOSE: The goal of this work is to develop a method to identify women at high risk for having breast cancer that is easily missed in regular mammography screening. Such a method will provide a rationale for selecting women for adjunctive screening. It goes beyond current risk assessment models...... that are not specifically adapted to reduce the number of interval cancers. METHOD AND MATERIALS: From the Dutch breast cancer screening program we collected 109 cancers that were screen negative and subsequently appeared as interval cancers, and 327 age matched healthy controls. To obtain mammograms without signs...

  7. Teaching syllabus for radiological aspects of breast cancer screening with digital mammography

    International Nuclear Information System (INIS)

    Van Ongeval, C.; Van Steen, A.; Bosmans, H.

    2008-01-01

    The purpose of this study is to discuss the content of our new accreditation programme for radiologists' reading digital mammograms in a screening setting and to report our first experience with the new course. The course consisted of a theoretical part, given by the medical physicist, and a practical part given by the radiologist. The practical session is closely linked with the theoretical part and a reading session. The material is fully digital and can be presented on different platforms. In practice, the need for parallel soft-copy reading sessions on high-end workstations limits the number of participants. A high level of interactivity was noted between teacher and participant, with a thorough discussion of different digital mammography systems during a single teaching course. The main challenge for the teacher turned out to be the collection of representative material and the continuous updating of the material: new systems, processing techniques and artefacts need to be included regularly. (authors)

  8. Breast cancer screening with mammography as part of our comprehensive medical check-up

    International Nuclear Information System (INIS)

    Ishii, Kaname; Kaburaki, Tomonori; Iwata, Keiko; Tsuneda, Atsushi; Mori, Kazuhiro; Takeyama, Shigeru; Tsuji, Hiroshi

    2012-01-01

    In the breast cancer screening program adopted by our hospital's Health Care Center as part of a comprehensive medical check-up, mammography (MMG) is performed in addition to a clinical breast examination to provide better screening quality. The clinical breast examination is performed by our surgeons. Two-view MMG is performed for women in their 40's and one-view MMG for the others. If any abnormality is detected in the clinical breast examination, or if MMG reveals abnormalities of category 3 or over, a more thorough diagnostic work-up is recommended. Each year, 1,400 or more women undergo breast cancer screening at the center, with an average recall rate of 12% and an average breast cancer detection rate of 0.14%. The high recall rate indicates the need for improvement of screening accuracy. Although the breast cancer detection rate and positive predictive value are somewhat low, the majority of the detected cases are early-stage breast cancer, thus demonstrating the efficacy of the screening. Herein, we describe the current state of MMG screening in our comprehensive medical check-up, along with a discussion of the screening procedure. However, further efforts are needed to improve screening accuracy. (author)

  9. Managed Care Penetration and the Use of Screening Mammography by Uninsured Women

    National Research Council Canada - National Science Library

    Garg, Pushkal

    2002-01-01

    ..., and increased waiting times for mammography. In this study we propose to examine whether there is an association between managed care penetration and rates of mammography among uninsured women between 50 and 64 years of age...

  10. Managed Care Penetration and the Use of Screening Mammography by Uninsured Women

    National Research Council Canada - National Science Library

    Garg, Pushkal

    2003-01-01

    ..., and increased waiting times for mammography. In this study, we examined whether there was an association between managed care penetration and rates of mammography among uninsured women between 50 and 64 years of age...

  11. Mammography calibration qualities establishment in a Mo-Mo clinical system

    International Nuclear Information System (INIS)

    Correa, E.L.; Santos, L.R. dos; Vivolo, V.; Potiens, M.P.A.

    2015-01-01

    In this study the mammography calibration qualities were established in a clinical mammography system. The objective is to provide the IPEN instruments calibration laboratory with both mammography calibration methods (using a clinical and an industrial system). The results showed a good behavior of mammography equipment, in terms of kVp, PPV and exposure time. The additional filtration of molybdenum is adequate, air-kerma rates were determined and spectra were obtained. (author)

  12. Mammography calibration qualities establishment in a Mo-Mo clinical system

    Energy Technology Data Exchange (ETDEWEB)

    Correa, E.L.; Santos, L.R. dos; Vivolo, V.; Potiens, M.P.A., E-mail: educorrea1905@gmail.com [Instituto de Pesquisas Energeticas e Nucleres (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    In this study the mammography calibration qualities were established in a clinical mammography system. The objective is to provide the IPEN instruments calibration laboratory with both mammography calibration methods (using a clinical and an industrial system). The results showed a good behavior of mammography equipment, in terms of kVp, PPV and exposure time. The additional filtration of molybdenum is adequate, air-kerma rates were determined and spectra were obtained. (author)

  13. Mammography: an update of the EUSOBI recommendations on information for women

    OpenAIRE

    Sardanelli, Francesco; Fallenberg, Eva M.; Clauser, Paola; Trimboli, Rubina M.; Camps-Herrero, Julia; Helbich, Thomas H.; Forrai, Gabor

    2016-01-01

    Abstract This article summarises the information to be offered to women about mammography. After a delineation of the aim of early diagnosis of breast cancer, the difference between screening mammography and diagnostic mammography is explained. The need to bring images and reports from the previous mammogram (and from other recent breast imaging examinations) is highlighted. Mammography technique and procedure are described with particular attention to discomfort and pain experienced by a sma...

  14. Addition of tomosynthesis to conventional digital mammography: effect on image interpretation time of screening examinations.

    Science.gov (United States)

    Dang, Pragya A; Freer, Phoebe E; Humphrey, Kathryn L; Halpern, Elkan F; Rafferty, Elizabeth A

    2014-01-01

    To determine the effect of implementing a screening tomosynthesis program on real-world clinical performance by quantifying differences between interpretation times for conventional screening mammography and combined tomosynthesis and mammography for multiple participating radiologists with a wide range of experience in a large academic center. In this HIPAA-compliant, institutional review board-approved study, 10 radiologists prospectively read images from screening digital mammography or screening combined tomosynthesis and mammography examinations for 1-hour-long uninterrupted sessions. Images from 3665 examinations (1502 combined and 2163 digital mammography) from July 2012 to January 2013 were interpreted in at least five sessions per radiologist per modality. The number of cases reported during each session was recorded for each reader. The experience level for each radiologist was also correlated to the average number of cases reported per hour. Analysis of variance was used to assess the number of studies interpreted per hour. A linear regression model was used to evaluate correlation between breast imaging experience and time taken to interpret images from both modalities. The mean number of studies interpreted in hour was 23.8 ± 0.55 (standard deviation) (range, 14.4-40.4) for combined tomosynthesis and mammography and 34.0 ± 0.55 (range, 20.4-54.3) for digital mammography alone. A mean of 10.2 fewer studies were interpreted per hour during combined tomosynthesis and mammography compared with digital mammography sessions (P tomosynthesis and mammography and 1.9 minutes ± 0.6 (range, 1.1-3.0) for digital mammography; interpretation time with combined tomosynthesis and mammography was 0.9 minute longer (47% longer) compared with digital mammography alone (P tomosynthesis and mammography examinations decreased (R(2) = 0.52, P = .03). Addition of tomosynthesis to mammography results in increased time to interpret images from screening examinations compared

  15. Cancer of the breast: induction by radiation and role of mammography

    Energy Technology Data Exchange (ETDEWEB)

    Simon, N

    1977-10-01

    Conflict in the management of cancer of the breast exists. Diagnosis by x-ray mammography provides early effective treatment, but x-ray exposure to the breast is cancerogenic. Prudence requires the use of low dose x-rays in mammography, and limits the use of x-ray mammography in the young. Guide lines for the indications for mammography are changing, and large scale population exposure to radiation should await results of demonstration projects in the United States.

  16. Adaptive Regularization of Neural Classifiers

    DEFF Research Database (Denmark)

    Andersen, Lars Nonboe; Larsen, Jan; Hansen, Lars Kai

    1997-01-01

    We present a regularization scheme which iteratively adapts the regularization parameters by minimizing the validation error. It is suggested to use the adaptive regularization scheme in conjunction with optimal brain damage pruning to optimize the architecture and to avoid overfitting. Furthermo......, we propose an improved neural classification architecture eliminating an inherent redundancy in the widely used SoftMax classification network. Numerical results demonstrate the viability of the method...

  17. Satellite teleradiology test bed for digital mammography

    Science.gov (United States)

    Barnett, Bruce G.; Dudding, Kathryn E.; Abdel-Malek, Aiman A.; Mitchell, Robert J.

    1996-05-01

    Teleradiology offers significant improvement in efficiency and patient compliance over current practices in traditional film/screen-based diagnosis. The increasing number of women who need to be screened for breast cancer, including those in remote rural regions, make the advantages of teleradiology especially attractive for digital mammography. At the same time, the size and resolution of digital mammograms are among the most challenging to support in a cost effective teleradiology system. This paper will describe a teleradiology architecture developed for use with digital mammography by GE Corporate Research and Development in collaboration with Massachusetts General Hospital under National Cancer Institute (NCI/NIH) grant number R01 CA60246-01. The testbed architecture is based on the Digital Imaging and Communications in Medicine (DICOM) standard, created by the American College of Radiology and National Electrical Manufacturers Association. The testbed uses several Sun workstations running SunOS, which emulate a rural examination facility connected to a central diagnostic facility, and uses a TCP-based DICOM application to transfer images over a satellite link. Network performance depends on the product of the bandwidth times the round- trip time. A satellite link has a round trip of 513 milliseconds, making the bandwidth-delay a significant problem. This type of high bandwidth, high delay network is called a Long Fat Network, or LFN. The goal of this project was to quantify the performance of the satellite link, and evaluate the effectiveness of TCP over an LFN. Four workstations have Sun's HSI/S (High Speed Interface) option. Two are connected by a cable, and two are connected through a satellite link. Both interfaces have the same T1 bandwidth (1.544 Megabits per second). The only difference was the round trip time. Even with large window buffers, the time to transfer a file over the satellite link was significantly longer, due to the bandwidth-delay. To

  18. Mammography screening. Benefits, harms, and informed choice.

    Science.gov (United States)

    Jørgensen, Karsten Juhl

    2013-04-01

    The rationale for breast cancer screening with mammography is deceptively simple: catch it early and reduce mortality from the disease and the need for mastectomies. But breast cancer is a complex problem, and complex problems rarely have simple solutions. Breast screening brings forward the time of diagnosis only slightly compared to the lifetime of a tumour, and screen-detected tumours have a size where metastases are possible. A key question is if screening can prevent metastases, and if the screen-detected tumours are small enough to allow breast conserving surgery rather than mastectomy. A mortality reduction can never justify a medical intervention in its own right, but must be weighed against the harms. Overdiagnosis is the most important harm of breast screening, but has gained wider recognition only in recent years. Screening leads to the detection and treatment of breast cancers that would otherwise never have been detected because they grow very slowly or not at all and would not have been detected in the woman's lifetime in the absence of screening. Screening therefore turns women into cancer patients unnecessarily, with life-long physical and psychological harms. The debate about the justification of breast screening is therefore not a simple question of whether screening reduces breast cancer mortality. This dissertation quantifies the primary benefits and harms of screening mammography. Denmark has an unscreened "control group" because only two geographical regions offered screening over a long time-period, which is unique in an international context. This was used to study breast cancer mortality, overdiagnosis, and the use of mastectomies. Also, a systematic review of overdiagnosis in five other countries allowed us to show that about half of the screen-detected breast cancers are overdiagnosed. An effect on breast cancer mortality is doubtful in today's setting, and overdiagnosis causes an increase in the use of mastectomies. These findings are

  19. Evidence on Synthesized Two-dimensional Mammography Versus Digital Mammography When Using Tomosynthesis (Three-dimensional Mammography) for Population Breast Cancer Screening.

    Science.gov (United States)

    Houssami, Nehmat

    2017-09-28

    One limitation of using digital breast tomosynthesis (3-dimensional [3D] mammography) technology with conventional (2-dimensional [2D]) mammography for breast cancer (BC) screening is the increased radiation dose from dual acquisitions. To resolve this problem, synthesized 2D (s2D) reconstruction images similar to 2D mammography were developed using tomosynthesis acquisitions. The present review summarizes the evidence for s2D versus digital mammography (2D) when using tomosynthesis (3D) for BC screening to address whether using s2D instead of 2D (alongside 3D) will yield similar detection measures. Comparative population screening studies have provided consistent evidence that cancer detection rates do not differ between integrated 2D/3D (range, 5.45-8.5/1000 screens) and s2D/3D (range, 5.03-8.8/1000 screens). Also, although the recall measures were relatively heterogeneous across included studies, little difference was found between the 2 modalities. The mean glandular dose for s2D/3D was 55% to 58% of that for 2D/3D. In the context of BC screening, s2D/3D involves substantially less radiation than 2D/3D and provides similar detection measures. Thus, consideration of transitioning to tomosynthesis screening should aim to use s2D/3D to minimize harm. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Response costs of mammography adherence: Iranian women's perceptions.

    Science.gov (United States)

    Khodayarian, Mahsa; Mazloomi-Mahmoodabad, Seyed Saied; Lamyian, Minoor; Morowatisharifabad, Mohammad Ali; Tavangar, Hossein

    2016-01-01

    Mammography as the most common secondary prevention method has known to be helpful in detecting breast cancer at the early stages. Low level of participation among women toward mammography uptake due to cultural beliefs is a great concern. This study aimed at exploring the perceptions of women about response costs of mammography adherence (MA) in Yazd, Iran. A qualitative study using semi-structured interviews was performed. Fourteen women,one oncology nurse, and a breast cancer survivor were purposefully interviewed. Interviews were transcribed verbatim and analyzed by directed content analysis method based on protection motivation theory (PMT). One main theme was emerged from the analysis namely called "response costs".Two main categories were also emerged from the data; (1) psychological barriers with six subcategories including "embarrassment," "worry about being diagnosed with cancer," "preoccupation with underlying disease," "misconception about mammography," "need for an accompanying person," and "internalizing the experiences of the others," and (2) maladaptive coping modes which encompassed three subcategories: "religious faith," "fatalism," and"avoidance and denial." Useful information was provided about the response costs of mammography utilization based on the perceptions of women. Cognitive barriers may be decreased by conducting modifications in women's awareness and attitude toward MA as well as changing the national health system infrastructures. Incorporating religious and cultural belief systems into MA educational programs through motivational messages is recommended.

  1. Comparison of TLD air kerma measurements in mammography

    International Nuclear Information System (INIS)

    Pernicka, F.

    2002-01-01

    The mammography examination is usually targeted at asymptomatic women so the narrow balance between benefit and undesirable effects is important. During the past few decades there have been significant advances in the equipment used for mammography. Even when the latest equipment and imaging systems are used, there is considerable variation from centre-to-centre in the choice of imaging parameters and techniques. There may be quite large differences in image quality and breast dose among the centres. A Co-ordinated Research Programme on 'Image quality and patient dose optimization in mammography in Eastern European Countries' was conducted by the IAEA, aiming at defining a methodology for the implementation of a quality assurance (QA) programme in mammography and at exercising the assessment of image quality and patient doses in a sample of hospitals in East European countries. Selected mammography clinics from Czech Republic, Hungary, Poland, Romania and Slovakia participate in the project. The teams consisted of experienced clinicians and physicists. They were supported by a group of experts (clinicians and medical physicists) from France, Italy and Spain. As an outcome of the project, improvements in these indicators (image quality and patient dose) after the implementation of the QA programme are expected. A comparison of dosimetry systems has been organized to assure that dosimetry measurements done in the frame of the project are comparable and traceable to the international measurement system. All five East European countries plus Spain took part in the exercise. The thermoluminescent (TL) method was selected for the comparison

  2. Mammography screening among Arab American women in metropolitan Detroit.

    Science.gov (United States)

    Schwartz, Kendra; Fakhouri, Monty; Bartoces, Monina; Monsur, Joseph; Younis, Amani

    2008-12-01

    Mammography screening behavior has not been well studied among Middle Eastern immigrant women. We conducted a telephone survey of 365 Arab American women residing in metropolitan Detroit, home to one of the largest populations of Middle Eastern immigrants in the US, to determine prevalence of factors associated with mammography, and attitudes and beliefs regarding mammography screening. Of 365 participants, only five were born in the US. Mean age was 53.2 years (SD 10.8). Two hundred twelve (58.1%) reported having mammogram every 1-2 years; 70% ever had mammogram. Age 50-64 years, having health insurance, married status, being in the US over 10 years, and being Lebanese were associated with mammography every 1-2 years. After adjusting for demographic factors, perceived seriousness of disease, general health motivation, and having fewer barriers were associated with more frequent screening. Appropriate mammography screening is decreased in this group. Targeted outreach regarding screening is appropriate for this population; however, lack of insurance may prevent adequate follow-up.

  3. Study of mammography in mass screening for breast cancer

    International Nuclear Information System (INIS)

    Kitada, Masahiro; Sakai, Hiroko; Kubo, Yoshihiko; Samejima, Natsuki; Kurowarabi, Kunio; Iwabuchi, Shuji.

    1995-01-01

    In order to examine the rate of correct diagnosis by mammography at initial mass screening for breast cancer, we carried out a retrospective study of mammography findings in 267 cases of breast cancer detected at Asahikawa Cancer Screening Center. The screening was performed by physical examination, and in cases where disease was suspected, mammography, ultrasonography, and needle biopsy were done. Mammographically, 172 cases (64.4%) were cancer-positive, 58 cases (21.7%) were suspicious for cancer, and 37 cases (13.9%) were cancer-negative. Patients below 50 years of age and those with tumors of small diameter (<20 mm) showed a significantly lower rate of cancer positivity than patients aged 50 years or more and those with tumors 20 mm or more in diameter. Mammographic abnormalities were not specific, since these changes were also found in normal subjects and patients with benign diseases. Therefore, we concluded that mammography without physical examination at initial mass screening has a high risk of missing breast cancer. Mass screening for breast cancer should be performed by physical examination involving inspection and palpation at the first instance. If any suspicious findings are obtained, mammography, ultrasonography, and needle biopsy should be done. (author)

  4. Population-based mammography screening: comparison of screen-film and full-field digital mammography with soft-copy reading--Oslo I study.

    Science.gov (United States)

    Skaane, Per; Young, Kari; Skjennald, Arnulf

    2003-12-01

    To compare screen-film and full-field digital mammography with soft-copy reading in a population-based screening program. Full-field digital and screen-film mammography were performed in 3,683 women aged 50-69 years. Two standard views of each breast were acquired with each modality. Images underwent independent double reading with use of a five-point rating scale for probability of cancer. Recall rates and positive predictive values were calculated. Cancer detection rates determined with both modalities were compared by using the McNemar test for paired proportions. Retrospective side-by-side analysis for conspicuity of cancers was performed by an external independent radiologist group with experience in both modalities. In 3,683 cases, 31 cancers were detected. Screen-film mammography depicted 28 (0.76%) malignancies, and full-field digital mammography depicted 23 (0.62%) malignancies. The difference between cancer detection rates was not significant (P =.23). The recall rate for full-field digital mammography (4.6%; 168 of 3,683 cases) was slightly higher than that for screen-film mammography (3.5%; 128 of 3,683 cases). The positive predictive value based on needle biopsy results was 46% for screen-film mammography and 39% for full-field digital mammography. Side-by-side image comparison for cancer conspicuity led to classification of 19 cancers as equal for probability of malignancy, six cancers as slightly better demonstrated at screen-film mammography, and six cancers as slightly better demonstrated at full-field digital mammography. There was no statistically significant difference in cancer detection rate between screen-film and full-field digital mammography. Cancer conspicuity was equal with both modalities. Full-field digital mammography with soft-copy reading is comparable to screen-film mammography in population-based screening.

  5. Assessment of mammography in Costa Rica

    International Nuclear Information System (INIS)

    Mora, Patricia

    2005-01-01

    An evaluation of national mammographic equipment was conducted, due to the increasing incidence of breast cancer in Costa Rican women. From June 2002 to October 2003, 2 of the 3 global indicators of image quality were evaluated, (mean glandular dose and phantom image) in 26 mammography machines facilitated by radiologists in charge of the same. The mean glandular dose found was 1.75 ± 0.60 mGy with a range of 0.8 a 2.56. Regarding quality image, 73% of the evaluated equipment was able to see 4 or more fibers, 53% saw 3 or more groups of microcalcifications and 82% saw 3 or more mass groups. All mean glandular doses were below the international reference dose value of 3 mGy. However, the analysis of phantom images showed that only 54% of all the equipment had a total score (sum of mass groups, fibers and microcalcifications) superior or equal to 10, as expected. A correct diagnosis that could eventually save the patient's life is the main objective of a mammogram; the factors that are degrading the images must be found and it might be necessary to increase the doses to achieve this. This study demonstrates the urgent necessity to introduce permanent quality control programs that will provide excellent images with the lowest internationally recommended doses.(author) [es

  6. Bavarian mammography screening program; Bayerisches Mammographiescreening (BMS)

    Energy Technology Data Exchange (ETDEWEB)

    Willgeroth, F. [Lenkungsausschuss BMS (Germany); Universitaetsfrauenklinik Innenstadt, Muenchen (Germany); Baumann, M.; Blaser, D.; Froschauer, S.; Kaeaeb, V.; Stich, V.; Thomaschewski, S.; Walter, D. [Kassenaerztliche Vereinigung Bayern (Germany); Crispin, A. [Klinikum Grosshadern der LMU Muenchen, Institut fuer Medizinische Informationsverarbeitung (Germany); Waal, J. de; Heywang-Koebrunner, S.; Rothe, R. [Lenkungsausschuss BMS (Germany); Hoelzel, D. [Lenkungsausschuss BMS (Germany); Klinikum Grosshadern der LMU Muenchen, Institut fuer Medizinische Informationsverarbeitung (Germany)

    2005-03-01

    In Bavaria since the 1st April 2003 we have been conducting a high quality mammography-screening carried out in individual practises (BMS). We have used the European and the S 3 guidelines. The best diagnosis is an early diagnosis of the breast carcinoma to save human life. Because of this and the high mortality rate due to this disease it is essential to have a mammogram screening program. There is no single one ideal way of constructing a screening program, it is always based on compromise within the particular health care-systems. Arising problems cannot be avoided, it is only possible when all parties work closely together that the BMS works properly. (orig.) [German] In Bayern laeuft seit dem 01.04.2003 ein qualitaetsgesichertes, flaechendeckendes Mammographiescreening mit dezentralem Charakter (BMS). Zugrunde liegen die Empfehlungen der European Guidelines sowie der S-3-Leitlinie. Die Vorverlegung der Diagnostik ist beim Mammakarzinom bis heute die effektivste Moeglichkeit, um das Leben von Frauen zu retten, die an diesem Krebs erkrankt sind. Daraus und aufgrund der hohen Mortalitaetsrate dieser Erkrankung leitet sich die Notwendigkeit eines Screeningprogramms ab. Dessen Aufbau kann unterschiedlich sein, denbesten Weg gibt es nicht; es wird sich immer eine Kompromissloesung ergeben, die sehr stark vom jeweiligen Gesundheitssystem beeinflusst wird. Auftretende Probleme sind vielschichtig. Nur durch gemeinsame Anstrengungen aller Beteiligten liess sich das Bayerische Mammographiescreening installieren. (orig.)

  7. Film quality in film mammography. Pt. 2

    International Nuclear Information System (INIS)

    Friedrich, M.; Weskamp, P.; Freie Univ. Berlin

    1976-01-01

    During consideration of three film mammographic systems, the concept of signal/noise ratio is developed as a quantitative measure of film quality. The ability to recognise detail related to detail size, film blackening and exposure geometry was studied for various systems, and the quality profiles are discussed. There is a considerable difference in quality between industrial films without screens and film-screen combinations; however, exposure geometry during mammography has a considerable effect which tends to reduce the difference. Consequently, detail sizes of 200 μ to 1,000 μ (including the majority of mammographic micro-calcifications) are shown about equally well. Contrast for the lo-dose system is somewhat less than for adequately exposed industrial film. Over-exposure with the lo-dose system, contrary to industrial film, rapidly leads to unsatisfactory results. On the other hand it is often not possible to obtain an adequate exposure when using industrial film. For these reasons it is often an advantage to examine large breasts and the dense breasts of young women with a film-screen combination which requires approximately one eighth of the dose necessary for industrial film. For small or easily compressable breasts best results are obtained, using an adequate exposure by employing industril film; radiation dose it then acceptable. (orig./ORU) [de

  8. Multiparameter optimization of mammography: an update

    Science.gov (United States)

    Jafroudi, Hamid; Muntz, E. P.; Jennings, Robert J.

    1994-05-01

    Previously in this forum we have reported the application of multiparameter optimization techniques to the design of a minimum dose mammography system. The approach used a reference system to define the physical imaging performance required and the dose to which the dose for the optimized system should be compared. During the course of implementing the resulting design in hardware suitable for laboratory testing, the state of the art in mammographic imaging changed, so that the original reference system, which did not have a grid, was no longer appropriate. A reference system with a grid was selected in response to this change, and at the same time the optimization procedure was modified, to make it more general and to facilitate study of the optimized design under a variety of conditions. We report the changes in the procedure, and the results obtained using the revised procedure and the up- to-date reference system. Our results, which are supported by laboratory measurements, indicate that the optimized design can image small objects as well as the reference system using only about 30% of the dose required by the reference system. Hardware meeting the specification produced by the optimization procedure and suitable for clinical use is currently under evaluation in the Diagnostic Radiology Department at the Clinical Center, NH.

  9. Optimization procedures in mammography: First results

    International Nuclear Information System (INIS)

    Espana Lopez, M. L.; Marcos de Paz, L.; Martin Rincon, C.; Jerez Sainz, I.; Lopez Franco, M. P.

    2001-01-01

    Optimization procedures in mammography using equipment with a unique target/filter combination can be carried out through such diverse factors as target optical density, technique factors for exposure, screen film combination or processing cycle, in order to obtain an image adequate for the diagnosis with an acceptable risk benefit balance. Diverse studies show an increase in the Standardised Detection Rate of invasive carcinomas with an increase in the optical density among others factors. In our hospital an optimisation process has been established, and as previous step, the target optical density has been increased up to 1,4 DO. The aim of this paper is to value the impact of optical density variation as much in the quality of image as in the entrance surface dose and the average dose to the glandular tissue, comparing them with the results obtained in a previous study. The study has been carried out in a sample of 106 patients, with an average age of 53,4 years, considering 212 clinical images corresponding to the two projections of a same breast with an average compressed thickness of 4,86 cm. An increase of 16,6% on the entrance surface dose and 18% on the average dose to the glandular tissue has been recorded. All the clinical images has been evaluated for the physician as adequate for diagnosis. (Author) 16 refs

  10. Wavelet processing techniques for digital mammography

    Science.gov (United States)

    Laine, Andrew F.; Song, Shuwu

    1992-09-01

    This paper introduces a novel approach for accomplishing mammographic feature analysis through multiresolution representations. We show that efficient (nonredundant) representations may be identified from digital mammography and used to enhance specific mammographic features within a continuum of scale space. The multiresolution decomposition of wavelet transforms provides a natural hierarchy in which to embed an interactive paradigm for accomplishing scale space feature analysis. Similar to traditional coarse to fine matching strategies, the radiologist may first choose to look for coarse features (e.g., dominant mass) within low frequency levels of a wavelet transform and later examine finer features (e.g., microcalcifications) at higher frequency levels. In addition, features may be extracted by applying geometric constraints within each level of the transform. Choosing wavelets (or analyzing functions) that are simultaneously localized in both space and frequency, results in a powerful methodology for image analysis. Multiresolution and orientation selectivity, known biological mechanisms in primate vision, are ingrained in wavelet representations and inspire the techniques presented in this paper. Our approach includes local analysis of complete multiscale representations. Mammograms are reconstructed from wavelet representations, enhanced by linear, exponential and constant weight functions through scale space. By improving the visualization of breast pathology we can improve the chances of early detection of breast cancers (improve quality) while requiring less time to evaluate mammograms for most patients (lower costs).

  11. Teaching atlas of mammography. 2. rev. ed.

    International Nuclear Information System (INIS)

    Tabar, L.; Dean, P.B.

    1985-01-01

    The purpose of this Atlas is to teach radiologists how to analyze mammograms and arrive at the correct diagnosis through proper evaluation of the findings. The illustrated cases cover practically the entire spectrum of breast abnormalities. They are based upon referred patient material as well as 80000 mammographic screening examinations. There are two basic steps in the interpretation of mammograms: perception and analysis. Since the greatest benefit of mammography lies in the detection of breast carcinoma in its earliest possible stages, every mammogram must be systematically surveyed for the subtle hints of malignancy. Perception is taught in this Atlas by describing a method for systematic viewing. The reader is then provided with a series of mammograms with obscure lesions to encourage practice with this method. With the help of a coordinate system, the lesions can be precisely located. Practice in perception continues throughout the Atlas. After detecting an abnormality on the mammogram, the diagnosis can be reached through a careful analysis of the X-ray signs. Additional projections, coned-down compression and magnetification views provide further help in this analytic workup. Rather than starting with the diagnosis and demonstrating typical findings, the approach of this Atlas is to teach the reader how to analyze the image and reach the correct diagnosis through proper evaluation of the X-ray signs. Prerequisites for the perception and evaluation of the X-ray signs are optimum technique, knowledge of anatomy and understanding of the pathological processes leading to the mammographic appearances. (orig.)

  12. Speculation on improving personal dosimetry in mammography

    International Nuclear Information System (INIS)

    Nicoll, J.J.

    1996-01-01

    The increasing importance of radiation protection of the patient in diagnostic radiology has created an interest in the dose individuals receive from X-ray mammography, although this is an area where the most important aspect of protection is based on the inter comparison of machines using phantoms and standard conditions. In 1987 the ICRP established the critical quantity as being the average absorbed dose to the glandular tissue of the breast, and identified a composition of 50% adipose; 50% glandular tissue as a reference. Several authors have published experimental and monte carlo simulation resuluts to enable the determination of this quantity from output, beam quality and compressed breast thickness. Many centres, including ourselves, have studied the distribution of radiation dose on this basis. The result is however dependant on the assumption made about tissue composition. It is apparently common knowledge among pathologists and frequently mentioned in general anatomy texts, that the amount of glandular tissue is independent of breast size; that is larger breasts will have a higher adipose:glandular tissue ratio. Such a systematic variation would lead to an overestimate of the dose being received by women with larger breasts. I will review the availabe pathology and demonstrate the effect of applying the assumed breast composition on our own data. (author)

  13. Semiconductor pixel detectors for digital mammography

    International Nuclear Information System (INIS)

    Novelli, M.; Amendolia, S.R.; Bisogni, M.G.; Boscardin, M.; Dalla Betta, G.F.; Delogu, P.; Fantacci, M.E.; Quattrocchi, M.; Rosso, V.; Stefanini, A.; Venturelli, L.; Zucca, S.

    2003-01-01

    We present some results obtained with silicon and gallium arsenide pixel detectors to be applied in the field of digital mammography. Even though GaAs is suitable for medical imaging applications thanks to its atomic number, which allows a very good detection efficiency, it often contains an high concentrations of traps which decrease the charge collection efficiency (CCE). So we have analysed both electrical and spectroscopic performance of different SI GaAs diodes as a function of concentrations of dopants in the substrate, in order to find a material by which we can obtain a CCE allowing the detection of all the photons that interact in the detector. Nevertheless to be able to detect low contrast details, efficiency and CCE are not the only parameters to be optimized; also the stability of the detection system is fundamental. In the past we have worked with Si pixel detectors; even if its atomic number does not allow a good detection efficiency at standard thickness, it has a very high stability. So keeping in mind the need to increase the Silicon detection efficiency we performed simulations to study the behaviour of the electrical potential in order to find a geometry to avoid the risk of electrical breakdown

  14. Semiconductor pixel detectors for digital mammography

    Energy Technology Data Exchange (ETDEWEB)

    Novelli, M. E-mail: marzia.novelli@pi.infn.it; Amendolia, S.R.; Bisogni, M.G.; Boscardin, M.; Dalla Betta, G.F.; Delogu, P.; Fantacci, M.E.; Quattrocchi, M.; Rosso, V.; Stefanini, A.; Venturelli, L.; Zucca, S

    2003-08-21

    We present some results obtained with silicon and gallium arsenide pixel detectors to be applied in the field of digital mammography. Even though GaAs is suitable for medical imaging applications thanks to its atomic number, which allows a very good detection efficiency, it often contains an high concentrations of traps which decrease the charge collection efficiency (CCE). So we have analysed both electrical and spectroscopic performance of different SI GaAs diodes as a function of concentrations of dopants in the substrate, in order to find a material by which we can obtain a CCE allowing the detection of all the photons that interact in the detector. Nevertheless to be able to detect low contrast details, efficiency and CCE are not the only parameters to be optimized; also the stability of the detection system is fundamental. In the past we have worked with Si pixel detectors; even if its atomic number does not allow a good detection efficiency at standard thickness, it has a very high stability. So keeping in mind the need to increase the Silicon detection efficiency we performed simulations to study the behaviour of the electrical potential in order to find a geometry to avoid the risk of electrical breakdown.

  15. MammoGrid: a mammography database

    CERN Multimedia

    2002-01-01

    What would be the advantages if physicians around the world could gain access to a unique mammography database? The answer may come from MammoGrid, a three-year project under the Fifth Framework Programme of the EC. Led by CERN, MammoGrid involves the UK (the Universities of Oxford, Cambridge and the West of England, Bristol, plus the company Mirada Solutions of Oxford), and Italy (the Universities of Pisa and Sassari and the Hospitals in Udine and Torino). The aim of the project is, in light of emerging GRID technology, to develop a Europe-wide database of mammograms. The database will be used to investigate a set of important healthcare applications as well as the potential of the GRID to enable healthcare professionals throughout the EU to work together effectively. The contributions of the partners include building the GRID-database infrastructure, developing image processing and Computer Aided Detection techniques, and making the clinical evaluation. The first project meeting took place at CERN in Sept...

  16. Comparative study on mammographic findings between conventional mammography and digital mammography

    International Nuclear Information System (INIS)

    Gonzalez Calle, Aurelio; Saldarriaga Jaramillo, Ximena; Zapata Walliser, Luz Estela; Mejia Restrepo, Jorge Hernando; Arango Martinez, Adriana; Velez Arango, Jorge Mario

    2007-01-01

    We performed conventional-film mammograms in 180 patients between 35 and 6 years and additionally, we added 2 digital CR technique images to each patient, either craneocaudal (90 patients) or oblique (90 patients). All images were interpreted independently by four radiologists for a total of 720 evaluations, who compared film versus digital images through a 5 mega pixel monitor (soft-copy), using a score scale using the following parameters: mass visualization, detection of micro-calcifications, architectural distortion, visibility of the skin line, and image sharpness and noise. Additionally the tissue density was classified as well as the BIRADS score. The data was processed with the Teleform program and analyzed by de SPSSS program. Results: 52.6% of the micro-calcifications were equally visualized with both systems, in 13.5% of the cases they were better visualized with digital mammography. Similarly, in 50% of the cases, the skin line was better visualized with the digital CR modality. Conclusion: the sharpness of the image was also better seen with the digital CR technique in 48.2%. On the contrary, more noise was seen in digital CR images (63%). digital mammography is a diagnostic alternative that can improve mammographic findings detection and finally become a useful tool in breast cancer diagnosis

  17. Screening mammography. A missed clinical opportunity? Results of the NCI [National Cancer Institute] Breast Cancer Screening Consortium and national health interview survey studies

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    Data from seven studies sponsored by the National Cancer Institute (NCI) were used to determine current rates of breast cancer screening and to identify the characteristics of and reasons for women not being screened. All seven studies were population-based surveys of women aged 50 to 74 years without breast cancer. While over 90% of non-Hispanic white respondents had regular sources of medical care, 46% to 76% had a clinical breast examination within the previous year, and only 25% to 41% had a mammogram. Less educated and poorer women had fewer mammograms. The two most common reasons women gave for never having had a mammogram were that they did not known they needed it and that their physician had not recommended it. Many physicians may have overlooked the opportunity to recommend mammography for older women when performing a clinical breast examination and to educate their patients about the benefit of screening mammography

  18. 75 FR 53966 - Regular Meeting

    Science.gov (United States)

    2010-09-02

    ... FARM CREDIT SYSTEM INSURANCE CORPORATION Regular Meeting AGENCY: Farm Credit System Insurance Corporation Board. SUMMARY: Notice is hereby given of the regular meeting of the Farm Credit System Insurance Corporation Board (Board). DATE AND TIME: The meeting of the Board will be held at the offices of the Farm...

  19. Online co-regularized algorithms

    NARCIS (Netherlands)

    Ruijter, T. de; Tsivtsivadze, E.; Heskes, T.

    2012-01-01

    We propose an online co-regularized learning algorithm for classification and regression tasks. We demonstrate that by sequentially co-regularizing prediction functions on unlabeled data points, our algorithm provides improved performance in comparison to supervised methods on several UCI benchmarks

  20. Bi-directional x-ray phase-contrast mammography.

    Directory of Open Access Journals (Sweden)

    Kai Scherer

    Full Text Available Phase-contrast x-ray imaging is a promising improvement of conventional absorption-based mammography for early tumor detection. This potential has been demonstrated recently, utilizing structured gratings to obtain differential phase and dark-field scattering images. However, the inherently anisotropic imaging sensitivity of the proposed mono-directional approach yields only insufficient diagnostic information, and has low diagnostic sensitivity to highly oriented structures. To overcome these limitations, we present a two-directional x-ray phase-contrast mammography approach and demonstrate its advantages by applying it to a freshly dissected, cancerous mastectomy breast specimen. We illustrate that the two-directional scanning procedure overcomes the insufficient diagnostic value of a single scan, and reliably detects tumor structures, independently from their orientation within the breast. Our results indicate the indispensable diagnostic necessity and benefit of a multi-directional approach for x-ray phase-contrast mammography.

  1. Estimation of patient dose in mammography screening examinations

    International Nuclear Information System (INIS)

    Suzuki, S.; Fujii, S.; Orito, T.; Asada, Y.; Koga, S.; Horita, K.; Kido, C.

    1996-01-01

    Mammography is one of the most effective examinations for detecting breast carcinoma. Although the dose is usually much higher than that in other types of X-ray examination, that is accepted by the patient because for fears of suffering cancer. Benefit of relatively high doses derived from mammographic examinations is considered to well exceed the risk of cancer induction by radiation exposure. The purpose of this study is to investigate patient dose of mammography in Japan by questionnaire sent to 531 institutions selected from whole Japan and direct measurements carried out in 28 hospitals in Aichi Prefecture. The user's guide in mammography published by NCRP and Quality Assurance Program of American College of Radiology were used to assess the exposure and image quality of mammogram. (author)

  2. Physical image quality of computed radiography in mammography system

    International Nuclear Information System (INIS)

    Norriza Mohd Isa; Muhammad Jamal Isa; Wan Muhamad Saridan Wan Hassan; Fatimah Othman

    2013-01-01

    Full-text: Mammography is a screening procedure that mostly used for early detection of breast cancer. In digital imaging system, Computed Radiography is a cost-effective technology that applied indirect conversion detector. The paper presents physical image quality parameter measurements namely modulation transfer function (MTF), normalized noise power spectrum (NNPS) and detective quantum efficiency (DQE) of Computed Radiography in mammography system. MTF was calculated from two different orientations of slanted images of an edge test device and NNPS was estimated using flat-field image. Both images were acquired using a standard mammography beam quality. DQE was determined by applying the MTF and NNPS values into our developed software program. Both orientations have similar DQE characteristics. (author)

  3. Ultra-Fast Image Reconstruction of Tomosynthesis Mammography Using GPU.

    Science.gov (United States)

    Arefan, D; Talebpour, A; Ahmadinejhad, N; Kamali Asl, A

    2015-06-01

    Digital Breast Tomosynthesis (DBT) is a technology that creates three dimensional (3D) images of breast tissue. Tomosynthesis mammography detects lesions that are not detectable with other imaging systems. If image reconstruction time is in the order of seconds, we can use Tomosynthesis systems to perform Tomosynthesis-guided Interventional procedures. This research has been designed to study ultra-fast image reconstruction technique for Tomosynthesis Mammography systems using Graphics Processing Unit (GPU). At first, projections of Tomosynthesis mammography have been simulated. In order to produce Tomosynthesis projections, it has been designed a 3D breast phantom from empirical data. It is based on MRI data in its natural form. Then, projections have been created from 3D breast phantom. The image reconstruction algorithm based on FBP was programmed with C++ language in two methods using central processing unit (CPU) card and the Graphics Processing Unit (GPU). It calculated the time of image reconstruction in two kinds of programming (using CPU and GPU).

  4. Quality Control in Mammography: Image Quality and Patient Doses

    International Nuclear Information System (INIS)

    Ciraj Bjelac, O.; Arandjic, D.; Boris Loncar, B.; Kosutic, D.

    2008-01-01

    Mammography is method of choice for early detection of breast cancer. The purpose of this paper is preliminary evaluation the mammography practice in Serbia, in terms of both quality control indicators, i.e. image quality and patient doses. The survey demonstrated considerable variations in technical parameters that affect image quality and patients doses. Mean glandular doses ranged from 0.12 to 2.8 mGy, while reference optical density ranged from 1.2 to 2.8. Correlation between image contrast and mean glandular doses was demonstrated. Systematic implementation of quality control protocol should provide satisfactory performance of mammography units and maintain satisfactory image quality and keep patient doses as low as reasonably practicable. (author)

  5. The dose and image quality in mammography in Macedonia

    International Nuclear Information System (INIS)

    Gershan, V.

    2007-01-01

    Complete test of publication follows. Mean Glandular Dose (MGD), dose distribution, phantom and quality of the real mammogram were studied for the first time in Macedonia. The study was conducted to review the condition of mammography equipment, to access the dose and image quality in mammography practices in Macedonia.. The purpose was to find out the weak points in the mammography practices in order to suggest improvements in the practices and establish quality control procedures. Under evaluation were 12 monographic machines. MGD was estimated using Entrance Surface Air KERMA at the breast surface K f measured free in air and appropriate conversion factors. Dose survey was curried by measurement and calculated of the HVLs and radiation output for 25-32 kVp and keeping record of the clinical parameters (breast thickness, kVp, mAs). Image quality was evaluated using the Mammographic Accreditation Phantom Gammex 156, PMMA plates and test tool for film processing.

  6. Quantification of breast arterial calcification using full field digital mammography

    International Nuclear Information System (INIS)

    Molloi, Sabee; Xu Tong; Ducote, Justin; Iribarren, Carlos

    2008-01-01

    Breast arterial calcification is commonly detected on some mammograms. Previous studies indicate that breast arterial calcification is evidence of general atherosclerotic vascular disease and it may be a useful marker of coronary artery disease. It can potentially be a useful tool for assessment of coronary artery disease in women since mammography is widely used as a screening tool for early detection of breast cancer. However, there are currently no available techniques for quantification of calcium mass using mammography. The purpose of this study was to determine whether it is possible to quantify breast arterial calcium mass using standard digital mammography. An anthropomorphic breast phantom along with a vessel calcification phantom was imaged using a full field digital mammography system. Densitometry was used to quantify calcium mass. A calcium calibration measurement was performed at each phantom thickness and beam energy. The known (K) and measured (M) calcium mass on 5 and 9 cm thickness phantoms were related by M=0.964K-0.288 mg (r=0.997 and SEE=0.878 mg) and M=1.004K+0.324 mg (r=0.994 and SEE=1.32 mg), respectively. The results indicate that accurate calcium mass measurements can be made without correction for scatter glare as long as careful calcium calibration is made for each breast thickness. The results also indicate that composition variations and differences of approximately 1 cm between calibration phantom and breast thickness introduce only minimal error in calcium measurement. The uncertainty in magnification is expected to cause up to 5% and 15% error in calcium mass for 5 and 9 cm breast thicknesses, respectively. In conclusion, a densitometry technique for quantification of breast arterial calcium mass was validated using standard full field digital mammography. The results demonstrated the feasibility and potential utility of the densitometry technique for accurate quantification of breast arterial calcium mass using standard digital

  7. Does health status influence intention regarding screening mammography?

    International Nuclear Information System (INIS)

    Park, Keeho; Park, Jong-Hyock; Park, Jae-Hyun; Kim, Hui-Jeong; Park, Bo-Yoon

    2010-01-01

    We analyzed information surveyed from a community-based sample of Korean women older than 40 years of age to understand the relationships between health status and screening behavior. In a cross-sectional population-based study, a two-stage, geographically stratified household-based sampling design was used for assembly of a probability sample of women aged 40-69 years living in Gunpo in Korea, resulting in a total sample size of 503 women. The primary outcome variable for this analysis was the respondent's intention to obtain a mammogram. Predictor variables included health status and other factors known to influence the use of cancer screening, such as age, education, income, marital status and the presence of co-morbid illnesses. Health status was assessed by using the EuroQol (EQ-5D). The median EQ visual analogue scale score was 75.0, ranging from 20 to 100. In bivariate analyses, the percentage of women reporting to have intention toward mammography use decreased with worsening health status. Women who had problems with mobility or anxiety/depression showed lower intention to undergo future screening mammography. Multivariate logistic regression confirmed that health status was significantly associated with intention toward mammography use. Anxiety or depression was an independent predictor of future screening mammography use. Health status is significantly associated with intention regarding screening mammography use. Physicians or other health professionals should be aware that health status is an important component for health promotion, and should pay more attention to clients' possible vulnerability in screening mammography use due to their poor health status. (author)

  8. Patterns and determinants of mammography screening in Lebanese women.

    Science.gov (United States)

    Elias, Nadia; Bou-Orm, Ibrahim R; Adib, Salim M

    2017-03-01

    The associations of ever using and/or repeating a mammography test with psychosocial and socio-demographic factors were surveyed in 2014 among Lebanese women ≥ 40. A sample of 2400 women was selected across Lebanon. Variables with significant bivariate associations with various types of behaviors were entered in multivariate analysis. Of the total, 105 women (4·4%) had never heard of mammography as a tool for early breast cancer detection. Among the remaining 2295, 45% had ever used it, of whom 10% had obtained it for the first time within the 12 months preceding the survey. Repeaters were 67% of 926 women who had the time opportunity to do so (median lifetime frequency: 2). Older age, higher socio-economic status (SES) and living within the Greater Beirut (GB) area were significantly associated with ever-use. Within GB, psychosocial factors such as perceived susceptibility and benefits were most strongly associated with ever-use. Outside GB, socio-economic advantage seemed to mostly affect ever-use. Only 4% reported opposition from husbands to their mammography, and husband's support was significant for adherence to mammography guidelines mostly outside GB. Higher education emerged also as a significant socio-demographic determinant for ever-repeating in all regions. Perceived comfort of the previous test strongly affected the likelihood of repeating it. Providing mammography free-of-charge may alleviate some obstacles among women with socio-economic disadvantage. Stressing that good results one year do not make the cancer less likely or repeating the test less important, as well as improving the comfort of mammography testing could ensure test repeating.

  9. Breast Cancer Detection: Mammography and other methods in breast imaging, second edition

    International Nuclear Information System (INIS)

    Bassett, L.W.; Gold, R.H.

    1987-01-01

    The text addresses mammography and the advantages and limitations of other breast imaging methods presently available. The establishment of X-ray mammography as the safest and most accurate noninvasive method of early, nonpalpable breast cancer detection is addressed in the first section of the book. The second section emphasizes the signs of early cancer, the complete mammographic examination, and the team approach to diagnosis. The advantages and limitations of film-screen mammography, zero mammography, breast ultrasound, thermography, light scanning, magnetic resonance imaging, and ductography are highlighted as alternate methods of detection. The benefits of mammography, and its unmatched value in screeening for breast cancer, are presented in the final section

  10. Statistical Texture Model for mass Detection in Mammography

    Directory of Open Access Journals (Sweden)

    Nicolás Gallego-Ortiz

    2013-12-01

    Full Text Available In the context of image processing algorithms for mass detection in mammography, texture is a key feature to be used to distinguish abnormal tissue from normal tissue. Recently, a texture model based on a multivariate Gaussian mixture was proposed, of which the parameters are learned in an unsupervised way from the pixel intensities of images. The model produces images that are probabilistic maps of texture normality and it was proposed as a visualization aid for diagnostic by clinical experts. In this paper, the usability of the model is studied for automatic mass detection. A segmentation strategy is proposed and evaluated using 79 mammography cases.

  11. Hidden costs of low-cost screening mammography

    International Nuclear Information System (INIS)

    Cyrlak, D.

    1987-01-01

    Twenty-two hundred women in Orange County, California, took part in a low-cost mammography screening project sponsored by the American Cancer Society and the KCBS-TV. Patients were followed up by telephone and questioned about actual costs incurred as a result of screening mammography, including costs of repeated and follow-up mammograms, US examinations and surgical consultations. The total number of biopsies, cancers found, and the costs involved were investigated. The authors' results suggest that particularly in centers with a high positive call rate, the cost of screening mammograms accounts for only a small proportion of the medical costs

  12. Focused two-dimensional antiscatter grid for mammography

    International Nuclear Information System (INIS)

    Makarova, O.V.; Moldovan, N.; Tang, C.-M.; Mancini, D.C.; Divan, R.; Zyryanov, V.N.; Ryding, D.C.; Yaeger, J.; Liu, C.

    2002-01-01

    We are developing freestanding high-aspect-ratio, focused, two-dimensional antiscatter grids for mammography using deep x-ray lithography and copper electroforming. The exposure is performed using x-rays from bending magnet beamline 2-BM at the Advanced Photon Source (APS) of Argonne National Laboratory. A 2.8-mm-thick prototype freestanding copper antiscatter grid with 25 (micro)m-wide parallel cell walls and 550 (micro)m periodicity has been fabricated. The progress in developing a dynamic double-exposure technique to create the grid with the cell walls aligned to a point x-ray source of the mammography system is discussed

  13. Dosimetry in a torso phantom during a mammography

    International Nuclear Information System (INIS)

    Hernandez O, M.; Duran M, H. A.; Pinedo S, A.; Salas L, M. A.; Hernandez D, V. M.; Vega C, H. R.; Rivera M, T.; Ventura M, J.

    2009-10-01

    Two dosimetric magnitudes, the absorbed dose and the kerma in air to the entrance of torso have been determined. These dosimetric magnitudes are due to the radiation that is dispersed in the mammary gland when the patient undergoes a mammography study. The kerma to the entrance of the torso and the absorbed dose by the torso was obtained in a phantom of paraffin and with thermoluminescent dosemeters of ZrO 2 . The dosemeters were placed on the surface of the torso phantom while the mammography was carried out. (author)

  14. Contrast-enhanced Spectral Mammography: Technique, Indications, and Clinical Applications.

    Science.gov (United States)

    Bhimani, Chandni; Matta, Danielle; Roth, Robyn G; Liao, Lydia; Tinney, Elizabeth; Brill, Kristin; Germaine, Pauline

    2017-01-01

    Contrast-enhanced spectral mammography (CESM) combines the benefits of full field digital mammography with the concept of tumor angiogenesis. Technique and practical applications of CESM are discussed. An overview of the technique is followed by a demonstration of practical applications of CESM in our practice. We have successfully implemented CESM into our practice as a screening, diagnostic, staging, and treatment response tool. It is important to understand the technique of CESM and how to incorporate it into practice. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  15. Factors influencing elderly women's mammography screening decisions: implications for counseling

    Directory of Open Access Journals (Sweden)

    Davis Roger B

    2007-11-01

    Full Text Available Abstract Background Although guidelines recommend that clinicians consider life expectancy before screening older women for breast cancer, many older women with limited life expectancies are screened. We aimed to identify factors important to mammography screening decisions among women aged 80 and older compared to women aged 65–79. Methods Telephone surveys of 107 women aged 80+ and 93 women aged 65–79 randomly selected from one academic primary care practice who were able to communicate in English (60% response rate. The survey addressed the following factors in regards to older women's mammography screening decisions: perceived importance of a history of breast disease, family history of breast cancer, doctor's recommendations, habit, reassurance, previous experience, mailed reminder cards, family/friend's recommendations or experience with breast cancer, age, health, and media. The survey also assessed older women's preferred role in decision making around mammography screening. Results Of the 200 women, 65.5% were non-Hispanic white and 82.8% were in good to excellent health. Most (81.3% had undergone mammography in the past 2 years. Regardless of age, older women ranked doctor's recommendations as the most important factor influencing their decision to get screened. Habit and reassurance were the next two highly ranked factors influencing older women to get screened. Among women who did not get screened, women aged 80 and older ranked age and doctor's counseling as the most influential factors and women aged 65–79 ranked a previous negative experience with mammography as the most important factor. There were no significant differences in preferred role in decision-making around mammography screening by age, however, most women in both age groups preferred to make the final decision on their own (46.6% of women aged 80+ and 50.5% of women aged 65–79. Conclusion While a doctor's recommendation is the most important factor influencing

  16. Factors influencing elderly women's mammography screening decisions: implications for counseling.

    Science.gov (United States)

    Schonberg, Mara A; McCarthy, Ellen P; York, Meghan; Davis, Roger B; Marcantonio, Edward R

    2007-11-16

    Although guidelines recommend that clinicians consider life expectancy before screening older women for breast cancer, many older women with limited life expectancies are screened. We aimed to identify factors important to mammography screening decisions among women aged 80 and older compared to women aged 65-79. Telephone surveys of 107 women aged 80+ and 93 women aged 65-79 randomly selected from one academic primary care practice who were able to communicate in English (60% response rate). The survey addressed the following factors in regards to older women's mammography screening decisions: perceived importance of a history of breast disease, family history of breast cancer, doctor's recommendations, habit, reassurance, previous experience, mailed reminder cards, family/friend's recommendations or experience with breast cancer, age, health, and media. The survey also assessed older women's preferred role in decision making around mammography screening. Of the 200 women, 65.5% were non-Hispanic white and 82.8% were in good to excellent health. Most (81.3%) had undergone mammography in the past 2 years. Regardless of age, older women ranked doctor's recommendations as the most important factor influencing their decision to get screened. Habit and reassurance were the next two highly ranked factors influencing older women to get screened. Among women who did not get screened, women aged 80 and older ranked age and doctor's counseling as the most influential factors and women aged 65-79 ranked a previous negative experience with mammography as the most important factor. There were no significant differences in preferred role in decision-making around mammography screening by age, however, most women in both age groups preferred to make the final decision on their own (46.6% of women aged 80+ and 50.5% of women aged 65-79). While a doctor's recommendation is the most important factor influencing elderly women's mammography screening decisions, habit and reassurance

  17. Statistical methods for determining the effect of mammography screening

    DEFF Research Database (Denmark)

    Lophaven, Søren

    2016-01-01

    In an overview of five randomised controlled trials from Sweden, a reduction of 29% was found in breast cancer mortality in women aged 50-69 at randomisation after a follow up of 5-13 years. Organised, population based, mammography service screening was introduced on the basis of these resultsin...... in 2007-2008. Women aged 50-69 were invited to screening every second year. Taking advantage of the registers of population and health, we present statistical methods for evaluating the effect of mammography screening on breast cancer mortality (Olsen et al. 2005, Njor et al. 2015 and Weedon-Fekjær etal...

  18. Mammography at reduced doses: present performance and future possibilities

    International Nuclear Information System (INIS)

    Muntz, E.P.; Wilkinson, E.; George, F.W.

    1980-01-01

    Reduced dose mammography is assessed with the aid of very recent work. It is concluded that there are technical and clinical reasons for believing that the reduced dose systems and their interpreters should perform more effectively than their predecessors. Review of known technologic achievements suggests a possible 6 to 7 reduction factor from present screen-film mammography dose levels without sacficifing image quality. Reasonable estimates of representative doses presently achieved by both xeroradiography and screen-film systems are given. The screen-film value is about 3 times higher than some previous

  19. Image Quality in Screening Mammography in Croatia

    International Nuclear Information System (INIS)

    Brnic, Z.; Klasic, B.; Popic-Ramac, J.; Ljevar, A.

    2011-01-01

    Mortality reduction through screening mammography (SMG) is possible only with examination of high image quality (IQ), which should be performed with acceptable patient breast radiation dose (BRD). Besides film processing control, equipment assessment with breast phantom and dosimetry, periodical external mammographic IQ assessment (MIQA) is needed, including image labelling (L), breast positioning (BP), exposure (EX) and artefacts (AR) assessment. The nationwide breast cancer screening program (NBSP) has been introduced in Croatia in 2006, and the MIQA is initiated as the first step in establishing quality assurance/quality control (QA/QC) framework in breast imaging in Croatia. The current study was aimed: (1) to provide objective evidence about the technical MIQ in NBSP in Croatia, (2) to compare MIQ between different types of mammographic units (MUs), (3) to identify the common deficiencies, and (4) to propose corrective activities. Mammograms (MGs) for IQA were collected from a total of 84 MUs which participate in NBSP, which represents 70 % of all MUs nationwide: A total of 420 MG examinations were reviewed. Each MU was requested to submit ''what they consider to be their five best representative MGs, each one performed in one of five consecutive workdays''. Mean age of MG machines was 7.76 years (range 2 - 21), with no difference between four MU types. This very first study of MIQ in Croatia corroborated our intuitive impression of inadequate IQ, staff training and equipment in many MUs nationwide. As MIQ strongly influences BC detection rate, suboptimal QA/QC always carries a risk to compromise the success of NBSP. Deficiencies in SMG, especially in ID and BP reflect different level of competency of radiological staff in Croatia. Differences in MIQ in various MU types are determined by their organization, equipment, education, working habits and motivation. More efforts are needed to train both RTs and radiologists to implement and maintain QA/QC in their

  20. Eighteen cases of small breast cancer: a comparative study of mammography, CT scan and pathology

    International Nuclear Information System (INIS)

    Wu Yaopan; Lin Haogao; Cai Peiqiang; Ouyang Yi; Zhang Weizhang; Lu Bingui

    2003-01-01

    Objective: To improve the early diagnosis of breast cancer through a study of the mammography and CT findings of small breast cancer. Methods: The mammography and CT findings of 18 cases of small breast cancer (φ≤2.0 cm in diameter) were studied and compared with pathological results. Results: The diagnostic accuracy of CT and mammography was 83% and 61%, respectively. There was a statistical difference between both modalities (P<0.05), CT scan was superior to mammography. However, there was no difference between them when assessing the lesion arising in F-type breast. In detecting breast fine cluster of calcification, the sensitivity of mammography was better than CT scan. Conclusion: The patient suspected of small breast cancer should take mammography as the first evaluation. CT scan is reserved for the further investigation. The mammography combined with CT scan can improve the early diagnostic rate of breast cancer

  1. Continuum-regularized quantum gravity

    International Nuclear Information System (INIS)

    Chan Huesum; Halpern, M.B.

    1987-01-01

    The recent continuum regularization of d-dimensional Euclidean gravity is generalized to arbitrary power-law measure and studied in some detail as a representative example of coordinate-invariant regularization. The weak-coupling expansion of the theory illustrates a generic geometrization of regularized Schwinger-Dyson rules, generalizing previous rules in flat space and flat superspace. The rules are applied in a non-trivial explicit check of Einstein invariance at one loop: the cosmological counterterm is computed and its contribution is included in a verification that the graviton mass is zero. (orig.)

  2. Film-Screen Mammography versus digital storage plate mammography: Hard copy and monitor display of microcalcifications and focal findings - A retrospective clinical and histologic analysis

    International Nuclear Information System (INIS)

    Schulz-Wendtland, R.; Wenkel, E.; Aichinger, U.; Tartsch, M.; Kuchar, I.; Bautz, W.

    2003-01-01

    Purpose: A retrospective clinical-histological study to determine the diagnostic accuracy of mammography using conventional screen-film cassettes (hard copy), high-resolution digital phosphor storage plates (hard copy) and monitor display (soft copy) for microcalcifications and focal lesions (BI-RADS TM category 4 or 5). Materials and methods: From April to November 2001, 76 patients underwent conventional film-screen mammography and, after diagnosis and preoperative wire localization, digital mammography with the same exposure parameters. Five investigators retrospectively determined the diagnosis after the operation from randomly distributed mediolateral views (hard-copy reading) and from the monitor display (soft-copy reading). These results were correlated with the final histology. Results: The accuracy of conventional screen-film mammography, digital mammography and monitor-displayed mammography was 67%, 65% and 68% for all findings, (n = 76), 59%, 59% and 68% for microcalcifications (n = 44) and 75%, 72% and 63% for focal lesions (n = 32). The overall results showed no difference. Conclusions: Our findings indicate equivalence of conventional screen-film mammography, high-resolution digital phosphor storage plate mammography and monitor-displayed mammography. (orig.) [de

  3. Full-field digital mammography versus computed radiology mammography: comparison in image quality and radiation dose

    International Nuclear Information System (INIS)

    Zhao Yongxia; Song Shaojuan; Liu Chuanya; Qi Hengtao; Qin Weichang

    2008-01-01

    Objective: To investigate the differences in image quality and radiation dose between full- field digital mammography (FFDM) system and compute radiology mammography (CRM) system. Methods: The ALVIM mammographic phantom was exposed by FFDM system with automatic exposure control (AEC) and then exposed by CRM system with the unique imaging plank on the same condition. The FFDM system applied the same kV value and the different mAs values (14, 16, 18, 22 and 24 mAs), and the emission skin dose (ESD) and the average gland dose (AGD) were recorded for the above-mentioned exposure factors. All images were read by five experienced radiologists under the same condition and judged based on 5-point scales. And then receive operating characteristic (ROC) curve was drawn and the probability (P det ) values were calculated. The data were statistically processed with ANOVA. Results: The P det values of calcifications and lesion lump were higher with FFDM system than with CRM system at the same dose (1.36 mGy). Especially, for microcalcifications and lesion lump, the largest difference of the P det value was 0.215, and that of lesion lump was 0.245. In comparison with CRM system, the radiation dose of FFDM system could be reduced at the same P det value. The ESD value was reduced by 26%, and the ACD value was reduced by 41%. When the mAs value exceed AEC value, the P det value almost had no change, though the radiation dose was increased. Conclusions: The detection rates of microcalcifications and lesion lump with FFDM system are proven to be superior to CRM system at the same dose. The radiation dose of FFDM system was less than CRM system for the same image quality. (authors)

  4. Imaging performance of an amorphous selenium digital mammography detector in a breast tomosynthesis system

    International Nuclear Information System (INIS)

    Zhao Bo; Zhao Wei

    2008-01-01

    In breast tomosynthesis a rapid sequence of N images is acquired when the x-ray tube sweeps through different angular views with respect to the breast. Since the total dose to the breast is kept the same as that in regular mammography, the exposure used for each image of tomosynthesis is 1/N. The low dose and high frame rate pose a tremendous challenge to the imaging performance of digital mammography detectors. The purpose of the present work is to investigate the detector performance in different operational modes designed for tomosynthesis acquisition, e.g., binning or full resolution readout, the range of view angles, and the number of views N. A prototype breast tomosynthesis system with a nominal angular range of ±25 deg. was used in our investigation. The system was equipped with an amorphous selenium (a-Se) full field digital mammography detector with pixel size of 85 μm. The detector can be read out in full resolution or 2x1 binning (binning in the tube travel direction). The focal spot blur due to continuous tube travel was measured for different acquisition geometries, and it was found that pixel binning, instead of focal spot blur, dominates the detector modulation transfer function (MTF). The noise power spectrum (NPS) and detective quantum efficiency (DQE) of the detector were measured with the exposure range of 0.4-6 mR, which is relevant to the low dose used in tomosynthesis. It was found that DQE at 0.4 mR is only 20% less than that at highest exposure for both detector readout modes. The detector temporal performance was categorized as lag and ghosting, both of which were measured as a function of x-ray exposure. The first frame lags were 8% and 4%, respectively, for binning and full resolution mode. Ghosting is negligible and independent of the frame rate. The results showed that the detector performance is x-ray quantum noise limited at the low exposures used in each view of tomosynthesis, and the temporal performance at high frame rate (up to

  5. New regular black hole solutions

    International Nuclear Information System (INIS)

    Lemos, Jose P. S.; Zanchin, Vilson T.

    2011-01-01

    In the present work we consider general relativity coupled to Maxwell's electromagnetism and charged matter. Under the assumption of spherical symmetry, there is a particular class of solutions that correspond to regular charged black holes whose interior region is de Sitter, the exterior region is Reissner-Nordstroem and there is a charged thin-layer in-between the two. The main physical and geometrical properties of such charged regular black holes are analyzed.

  6. Regular variation on measure chains

    Czech Academy of Sciences Publication Activity Database

    Řehák, Pavel; Vitovec, J.

    2010-01-01

    Roč. 72, č. 1 (2010), s. 439-448 ISSN 0362-546X R&D Projects: GA AV ČR KJB100190701 Institutional research plan: CEZ:AV0Z10190503 Keywords : regularly varying function * regularly varying sequence * measure chain * time scale * embedding theorem * representation theorem * second order dynamic equation * asymptotic properties Subject RIV: BA - General Mathematics Impact factor: 1.279, year: 2010 http://www.sciencedirect.com/science/article/pii/S0362546X09008475

  7. Manifold Regularized Correlation Object Tracking

    OpenAIRE

    Hu, Hongwei; Ma, Bo; Shen, Jianbing; Shao, Ling

    2017-01-01

    In this paper, we propose a manifold regularized correlation tracking method with augmented samples. To make better use of the unlabeled data and the manifold structure of the sample space, a manifold regularization-based correlation filter is introduced, which aims to assign similar labels to neighbor samples. Meanwhile, the regression model is learned by exploiting the block-circulant structure of matrices resulting from the augmented translated samples over multiple base samples cropped fr...

  8. On geodesics in low regularity

    Science.gov (United States)

    Sämann, Clemens; Steinbauer, Roland

    2018-02-01

    We consider geodesics in both Riemannian and Lorentzian manifolds with metrics of low regularity. We discuss existence of extremal curves for continuous metrics and present several old and new examples that highlight their subtle interrelation with solutions of the geodesic equations. Then we turn to the initial value problem for geodesics for locally Lipschitz continuous metrics and generalize recent results on existence, regularity and uniqueness of solutions in the sense of Filippov.

  9. Condition Number Regularized Covariance Estimation.

    Science.gov (United States)

    Won, Joong-Ho; Lim, Johan; Kim, Seung-Jean; Rajaratnam, Bala

    2013-06-01

    Estimation of high-dimensional covariance matrices is known to be a difficult problem, has many applications, and is of current interest to the larger statistics community. In many applications including so-called the "large p small n " setting, the estimate of the covariance matrix is required to be not only invertible, but also well-conditioned. Although many regularization schemes attempt to do this, none of them address the ill-conditioning problem directly. In this paper, we propose a maximum likelihood approach, with the direct goal of obtaining a well-conditioned estimator. No sparsity assumption on either the covariance matrix or its inverse are are imposed, thus making our procedure more widely applicable. We demonstrate that the proposed regularization scheme is computationally efficient, yields a type of Steinian shrinkage estimator, and has a natural Bayesian interpretation. We investigate the theoretical properties of the regularized covariance estimator comprehensively, including its regularization path, and proceed to develop an approach that adaptively determines the level of regularization that is required. Finally, we demonstrate the performance of the regularized estimator in decision-theoretic comparisons and in the financial portfolio optimization setting. The proposed approach has desirable properties, and can serve as a competitive procedure, especially when the sample size is small and when a well-conditioned estimator is required.

  10. Condition Number Regularized Covariance Estimation*

    Science.gov (United States)

    Won, Joong-Ho; Lim, Johan; Kim, Seung-Jean; Rajaratnam, Bala

    2012-01-01

    Estimation of high-dimensional covariance matrices is known to be a difficult problem, has many applications, and is of current interest to the larger statistics community. In many applications including so-called the “large p small n” setting, the estimate of the covariance matrix is required to be not only invertible, but also well-conditioned. Although many regularization schemes attempt to do this, none of them address the ill-conditioning problem directly. In this paper, we propose a maximum likelihood approach, with the direct goal of obtaining a well-conditioned estimator. No sparsity assumption on either the covariance matrix or its inverse are are imposed, thus making our procedure more widely applicable. We demonstrate that the proposed regularization scheme is computationally efficient, yields a type of Steinian shrinkage estimator, and has a natural Bayesian interpretation. We investigate the theoretical properties of the regularized covariance estimator comprehensively, including its regularization path, and proceed to develop an approach that adaptively determines the level of regularization that is required. Finally, we demonstrate the performance of the regularized estimator in decision-theoretic comparisons and in the financial portfolio optimization setting. The proposed approach has desirable properties, and can serve as a competitive procedure, especially when the sample size is small and when a well-conditioned estimator is required. PMID:23730197

  11. Hessian-regularized co-training for social activity recognition.

    Science.gov (United States)

    Liu, Weifeng; Li, Yang; Lin, Xu; Tao, Dacheng; Wang, Yanjiang

    2014-01-01

    Co-training is a major multi-view learning paradigm that alternately trains two classifiers on two distinct views and maximizes the mutual agreement on the two-view unlabeled data. Traditional co-training algorithms usually train a learner on each view separately and then force the learners to be consistent across views. Although many co-trainings have been developed, it is quite possible that a learner will receive erroneous labels for unlabeled data when the other learner has only mediocre accuracy. This usually happens in the first rounds of co-training, when there are only a few labeled examples. As a result, co-training algorithms often have unstable performance. In this paper, Hessian-regularized co-training is proposed to overcome these limitations. Specifically, each Hessian is obtained from a particular view of examples; Hessian regularization is then integrated into the learner training process of each view by penalizing the regression function along the potential manifold. Hessian can properly exploit the local structure of the underlying data manifold. Hessian regularization significantly boosts the generalizability of a classifier, especially when there are a small number of labeled examples and a large number of unlabeled examples. To evaluate the proposed method, extensive experiments were conducted on the unstructured social activity attribute (USAA) dataset for social activity recognition. Our results demonstrate that the proposed method outperforms baseline methods, including the traditional co-training and LapCo algorithms.

  12. Hessian-regularized co-training for social activity recognition.

    Directory of Open Access Journals (Sweden)

    Weifeng Liu

    Full Text Available Co-training is a major multi-view learning paradigm that alternately trains two classifiers on two distinct views and maximizes the mutual agreement on the two-view unlabeled data. Traditional co-training algorithms usually train a learner on each view separately and then force the learners to be consistent across views. Although many co-trainings have been developed, it is quite possible that a learner will receive erroneous labels for unlabeled data when the other learner has only mediocre accuracy. This usually happens in the first rounds of co-training, when there are only a few labeled examples. As a result, co-training algorithms often have unstable performance. In this paper, Hessian-regularized co-training is proposed to overcome these limitations. Specifically, each Hessian is obtained from a particular view of examples; Hessian regularization is then integrated into the learner training process of each view by penalizing the regression function along the potential manifold. Hessian can properly exploit the local structure of the underlying data manifold. Hessian regularization significantly boosts the generalizability of a classifier, especially when there are a small number of labeled examples and a large number of unlabeled examples. To evaluate the proposed method, extensive experiments were conducted on the unstructured social activity attribute (USAA dataset for social activity recognition. Our results demonstrate that the proposed method outperforms baseline methods, including the traditional co-training and LapCo algorithms.

  13. Significance of screening mammography in the detection of breast diseases

    International Nuclear Information System (INIS)

    Ham, Soo Youn; Kim, Kyoung Ah; Oh, Yu Whan; Kim, Hong In; Chung, Kyoo Byung

    1995-01-01

    To evaluate the clinical significance of the screening mammography in the detection of the breast diseases, especially breast carcinoma. We analyzed 1,800 cases of mammography retrospectively. The mammography was done as a part of routine check in Health Counselling Center, Korea University Medical Center, during 9 months from November 1993 to July 1994. The age range was from 23 years to 76 years, mean 49.8 years, and the largest age group was 6th decade (31.4%). According to the mammographic findings, we divided the subjects into three groups; normal group, abnormal group in need of follow-up study, abnormal group requiring biopsy. On mammography, the normal group consisted of 1,534 cases (85%), and the abnormal group consisted of 266 cases (15%). The abnormal findings were benign-looking calcification (n = 140), fibroadeno ma (n = 29), fibrocystic changes (n = 27), cyst (n = 23), malignant lesion (n = 15) lipoma (n = 7), and others. In four of 15 cases, which were suspected to be malignant on mammograms, breast carcinoma was confirmed pathologically. In four cases of breast carcinoma, one was under 40 and the other 3 were over 50 years of age. All of the breast cancers were under 3 cm in size, and the mammographic findings of breast cancer included spiculated margin (n = 3), parenchymal distortion (n = 3), malignant calcification (n = 2) and enlarged axillary node (n = 1). Screening mammogram is helpful for early detection of non-palpable breast cancer, especially for women over 50 years of age

  14. Artificial Neural Networks in Mammography Interpretation and Diagnostic Decision Making

    Directory of Open Access Journals (Sweden)

    Turgay Ayer

    2013-01-01

    Full Text Available Screening mammography is the most effective means for early detection of breast cancer. Although general rules for discriminating malignant and benign lesions exist, radiologists are unable to perfectly detect and classify all lesions as malignant and benign, for many reasons which include, but are not limited to, overlap of features that distinguish malignancy, difficulty in estimating disease risk, and variability in recommended management. When predictive variables are numerous and interact, ad hoc decision making strategies based on experience and memory may lead to systematic errors and variability in practice. The integration of computer models to help radiologists increase the accuracy of mammography examinations in diagnostic decision making has gained increasing attention in the last two decades. In this study, we provide an overview of one of the most commonly used models, artificial neural networks (ANNs, in mammography interpretation and diagnostic decision making and discuss important features in mammography interpretation. We conclude by discussing several common limitations of existing research on ANN-based detection and diagnostic models and provide possible future research directions.

  15. Current perspectives on indications and limitations of mammography

    International Nuclear Information System (INIS)

    Pope, T.L. Jr.

    1983-01-01

    Women have a 7 percent natural lifetime risk of developing breast cancer, which is the leading cause of death in women aged 40 to 50 years. Most data suggest that the earlier the disease is diagnosed, the better the chance for cure. Women with ''minimal breast cancer'' have an actuarial 20-year survival rate of 93.2 percent. The majority of these breast cancers are diagnosed by mammography. The radiation doses from this technique have been dramatically decreased over the last ten years to about 0.1 to 0.6 rads per study. The two largest breast cancer screening studies, the Health Insurance Plan of Greater New York and the Breast Cancer Detection Demonstration Project, have shown conclusively that women over 50 years old can benefit from annual mammography and that certain groups can benefit from mammography at close intervals before the age of 50 years. This article describes the development of mammography and outlines current perspectives on its indications and limitations

  16. Study of signal-to-noise ratio in digital mammography

    Science.gov (United States)

    Kato, Yuri; Fujita, Naotoshi; Kodera, Yoshie

    2009-02-01

    Mammography techniques have recently advanced from those using analog systems (the screen-film system) to those using digital systems; for example, computed radiography (CR) and flat-panel detectors (FPDs) are nowadays used in mammography. Further, phase contrast mammography (PCM)-a digital technique by which images with a magnification of 1.75× can be obtained-is now available in the market. We studied the effect of the air gap in PCM and evaluated the effectiveness of an antiscatter x-ray grid in conventional mammography (CM) by measuring the scatter fraction ratio (SFR) and relative signal-to-noise ratio (rSNR) and comparing them between PCM and the digital CM. The results indicated that the SFRs for the CM images obtained with a grid were the lowest and that these ratios were almost the same as those for the PCM images. In contrast, the rSNRs for the PCM images were the highest, which means that the scattering of x-rays was sufficiently reduced by the air gap without the loss of primary x-rays.

  17. Predictors of Perceived Barriers to Mammography in Korean Women

    Directory of Open Access Journals (Sweden)

    Jung-Hee Kim, RN, PhD

    2008-06-01

    Conclusion: Nurses who work with Korean women for breast cancer screening need to assess these predictive factors, including health motivation and breast cancer fear. Further extensive research will be needed to demonstrate the relationship between breast cancer fatalism and perceived barriers to mammography.

  18. Early identification of iflammantory rheumatic bone disease via mammography technique

    International Nuclear Information System (INIS)

    Singer, F.; Jakic, L.

    1981-01-01

    A decisive improvement of early X-ray diagnosis of inflammatory rheumatic osseus changes becomes possible by means of an appropriate combination of film and foil of the type which has been in use in mammography for a long time. (orig.) [de

  19. Entrance surface dose measurements in mammography using thermoluminescence technique

    International Nuclear Information System (INIS)

    Rivera, T.; Vega C, H.R.; Manzanares A, E; Azorin, J.; Gonzalez, P.R.

    2007-01-01

    Full text: Of the various techniques that can be used for personnel dosimetry, thermoluminescence dosimetry (TLD) has emerged as a superior technique due to its manifold advantages over other methods of dose estimation. Various phosphors have been therefore investigated regarding their suitability for dosimetry. In this paper, a dosimetry system based on thermally stimulated luminescence (TSL) from zirconium oxide phosphors embedded in polytetrafluorethylene (ZrO 2 +PTFE) was developed for entrance surface doses (ES) measurements in mammography. Small ZrO 2 pellets of 5 mm in diameter and 0.8 mm in thickness were used. The reproducibility of measurements and linearity of ZrO 2 were also studied. The results were compared with those obtained from LiF:Mg,Cu,P usually used for the determination of absorbed dose in mammography. Measurements both per unit air kerma and In vivo were performed using a mammography unit model DMR (General Electric). The results showed that ZrO 2 TLDs can be used for the same X-ray dosimetry applications as LiF:Mg,Cu,P, with each type having the disadvantage of a response dependent on energy, particularly at low energies. These results indicate a considerable potential for use in routine control and In vivo ES measurements in mammography. (Author)

  20. Response costs of mammography adherence: Iranian women’sperceptions

    Directory of Open Access Journals (Sweden)

    Mahsa Khodayarian

    2016-06-01

    Conclusion: Useful information was provided about the response costs of mammography utilization based on the perceptions of women. Cognitive barriers may be decreased by conducting modifications in women’s awareness and attitude toward MA as well as changing the national health system infrastructures. Incorporating religious and cultural belief systems into MA educational programs through motivational messages is recommended.

  1. Development of an excel spreadsheet formean glandular dose in mammography

    International Nuclear Information System (INIS)

    Nagoshi, Kazuyo; Fujisaki, Tatsuya

    2008-01-01

    The purpose of this study was to develop an Excel spreadsheet to calculate mean glandular dose (D g ) in mammography using clinical exposure data. D g can be calculated as the product of incident air kerma (K a ) and D gN (i.e., D g =K a x D gN ). According to the method of Klein et al (Phys Med Biol 1997; 42: 651-671), K a was measured at the entrance surface with an ionization dosimeter. Normalized glandular dose (D gN ) coefficients, taking into account breast glandularity, were computed using Boone's method (Med Phys 2002; 29: 869-875). D gN coefficients can be calculated for any arbitrary X-ray spectrum. These calculation procedures were input into a Microsoft Excel spreadsheet. The resulting Excel spreadsheet is easy to use and is always applicable in the field of mammography. The exposure conditions concerning D g in clinical practice were also investigated in 22 women. Four exposure conditions (target/filter combination and tube voltage) were automatically selected in this study. This investigation found that average D g for each exposure was 1.9 mGy. Because it is recommended that quality control of radiation dose management in mammography is done using an American College of Radiology (ACR) phantom, information about patient dose is not obtained in many facilities. The present Excel spreadsheet was accordingly considered useful for optimization of exposure conditions and explanation of mammography to patients. (author)

  2. Radiology workstation for mammography: preliminary observations, eyetracker studies, and design

    Science.gov (United States)

    Beard, David V.; Johnston, Richard E.; Pisano, Etta D.; Hemminger, Bradley M.; Pizer, Stephen M.

    1991-07-01

    For the last four years, the UNC FilmPlane project has focused on constructing a radiology workstation facilitating CT interpretations equivalent to those with film and viewbox. Interpretation of multiple CT studies was originally chosen because handling such large numbers of images was considered to be one of the most difficult tasks that could be performed with a workstation. The authors extend the FilmPlane design to address mammography. The high resolution and contrast demands coupled with the number of images often cross- compared make mammography a difficult challenge for the workstation designer. This paper presents the results of preliminary work with workstation interpretation of mammography. Background material is presented to justify why the authors believe electronic mammographic workstations could improve health care delivery. The results of several observation sessions and a preliminary eyetracker study of multiple-study mammography interpretations are described. Finally, tentative conclusions of what a mammographic workstation might look like and how it would meet clinical demand to be effective are presented.

  3. Significance of screening mammography in the detection of breast diseases

    Energy Technology Data Exchange (ETDEWEB)

    Ham, Soo Youn; Kim, Kyoung Ah; Oh, Yu Whan; Kim, Hong In; Chung, Kyoo Byung [College of Medicine Korea University, Seoul (Korea, Republic of)

    1995-02-15

    To evaluate the clinical significance of the screening mammography in the detection of the breast diseases, especially breast carcinoma. We analyzed 1,800 cases of mammography retrospectively. The mammography was done as a part of routine check in Health Counselling Center, Korea University Medical Center, during 9 months from November 1993 to July 1994. The age range was from 23 years to 76 years, mean 49.8 years, and the largest age group was 6th decade (31.4%). According to the mammographic findings, we divided the subjects into three groups; normal group, abnormal group in need of follow-up study, abnormal group requiring biopsy. On mammography, the normal group consisted of 1,534 cases (85%), and the abnormal group consisted of 266 cases (15%). The abnormal findings were benign-looking calcification (n = 140), fibroadeno ma (n = 29), fibrocystic changes (n = 27), cyst (n = 23), malignant lesion (n = 15) lipoma (n = 7), and others. In four of 15 cases, which were suspected to be malignant on mammograms, breast carcinoma was confirmed pathologically. In four cases of breast carcinoma, one was under 40 and the other 3 were over 50 years of age. All of the breast cancers were under 3 cm in size, and the mammographic findings of breast cancer included spiculated margin (n = 3), parenchymal distortion (n = 3), malignant calcification (n = 2) and enlarged axillary node (n = 1). Screening mammogram is helpful for early detection of non-palpable breast cancer, especially for women over 50 years of age.

  4. Implications of Overdiagnosis: Impact on Screening Mammography Practices

    Science.gov (United States)

    Morris, Elizabeth; Feig, Stephen A.; Drexler, Madeline

    2015-01-01

    Abstract This review article explores the issue of overdiagnosis in screening mammography. Overdiagnosis is the screen detection of a breast cancer, histologically confirmed, that might not otherwise become clinically apparent during the lifetime of the patient. While screening mammography is an imperfect tool, it remains the best tool we have to diagnose breast cancer early, before a patient is symptomatic and at a time when chances of survival and options for treatment are most favorable. In 2015, an estimated 231,840 new cases of breast cancer (excluding ductal carcinoma in situ) will be diagnosed in the United States, and some 40,290 women will die. Despite these data, screening mammography for women ages 40–69 has contributed to a substantial reduction in breast cancer mortality, and organized screening programs have led to a shift from late-stage diagnosis to early-stage detection. Current estimates of overdiagnosis in screening mammography vary widely, from 0% to upwards of 30% of diagnosed cancers. This range reflects the fact that measuring overdiagnosis is not a straightforward calculation, but usually one based on different sets of assumptions and often biased by methodological flaws. The recent development of tomosynthesis, which creates high-resolution, three-dimensional images, has increased breast cancer detection while reducing false recalls. Because the greatest harm of overdiagnosis is overtreatment, the key goal should not be less diagnosis but better treatment decision tools. (Population Health Management 2015;18:S3–S11) PMID:26414384

  5. Geometric continuum regularization of quantum field theory

    International Nuclear Information System (INIS)

    Halpern, M.B.

    1989-01-01

    An overview of the continuum regularization program is given. The program is traced from its roots in stochastic quantization, with emphasis on the examples of regularized gauge theory, the regularized general nonlinear sigma model and regularized quantum gravity. In its coordinate-invariant form, the regularization is seen as entirely geometric: only the supermetric on field deformations is regularized, and the prescription provides universal nonperturbative invariant continuum regularization across all quantum field theory. 54 refs

  6. Screening mammography interpretation test: more frequent mistakes

    International Nuclear Information System (INIS)

    Gozzi, Gino; Ganzetti, Alessandra; Martinoli, Carlo; Bacigalupo, Lorenzo; Bodini, Maria; Fiorentino, Carla; Marini, Ugo Paolo; Santini, Dolores

    2005-01-01

    Purpose: To present the mammographic cases most commonly misinterpreted by the participants in the mammography self-test proposed by the Italian Society of Medical Radiology (SIRM) National Congress in Rimini, Italy, 2002, by analysing the findings responsible for errors, suggesting reasons for the errors, and assessing possible inadequacies in the format of the test. Materials and methods: The self-test was performed on the mammograms of 160 cases (32 positive and 128 negative for cancer as confirmed by histology). The mammograms had been taken in the four standard projections and placed on four multi-panel diaphanoscopes, each displaying a set of 40 cases comprising benign and malignant cases in equal proportions. The participants were given pre-printed forms on which to note down their diagnostic judgement. We evaluated a total of 134 fully-completed forms. Among these, we identified the 23 cases most frequently misread by over 15 participants in percentages varying between 40-90%. Of these cases, 10 were malignancies and 13 were negative mammograms. On review, we also assessed the diagnostic contribution of complementary investigations (not available the participants). The 134 fully-completed forms (all of the 40 cases) yielded a total of 5360 responses, 1180 of which (22.01%) were incorrect. Of these 823 out of the 4288 cases expected to be negative (19.2%) were false positive, and 357 out of the 1072 cases expected to be positive (33.3%) were false negative. As regards the 23 most frequently misread cases, these were 10/32 (31.25%) mammograms positive for malignancy and 13/128 (10.15%) negative mammograms or mammograms showing benign disease. The 10 malignancies included 7 infiltrating ductal carcinomas, 1 infiltrating cribriform carcinoma, 1 infiltrating tubular carcinoma, and 1 carcinoma in situ. The 13 cases of benign disease - as established by histology or long-term follow-up - mistaken for malignancies by the test participants were fibrocystic breast

  7. Postmortem validation of breast density using dual-energy mammography

    Energy Technology Data Exchange (ETDEWEB)

    Molloi, Sabee, E-mail: symolloi@uci.edu; Ducote, Justin L.; Ding, Huanjun; Feig, Stephen A. [Department of Radiological Sciences, University of California, Irvine, California 92697 (United States)

    2014-08-15

    Purpose: Mammographic density has been shown to be an indicator of breast cancer risk and also reduces the sensitivity of screening mammography. Currently, there is no accepted standard for measuring breast density. Dual energy mammography has been proposed as a technique for accurate measurement of breast density. The purpose of this study is to validate its accuracy in postmortem breasts and compare it with other existing techniques. Methods: Forty postmortem breasts were imaged using a dual energy mammography system. Glandular and adipose equivalent phantoms of uniform thickness were used to calibrate a dual energy basis decomposition algorithm. Dual energy decomposition was applied after scatter correction to calculate breast density. Breast density was also estimated using radiologist reader assessment, standard histogram thresholding and a fuzzy C-mean algorithm. Chemical analysis was used as the reference standard to assess the accuracy of different techniques to measure breast composition. Results: Breast density measurements using radiologist reader assessment, standard histogram thresholding, fuzzy C-mean algorithm, and dual energy were in good agreement with the measured fibroglandular volume fraction using chemical analysis. The standard error estimates using radiologist reader assessment, standard histogram thresholding, fuzzy C-mean, and dual energy were 9.9%, 8.6%, 7.2%, and 4.7%, respectively. Conclusions: The results indicate that dual energy mammography can be used to accurately measure breast density. The variability in breast density estimation using dual energy mammography was lower than reader assessment rankings, standard histogram thresholding, and fuzzy C-mean algorithm. Improved quantification of breast density is expected to further enhance its utility as a risk factor for breast cancer.

  8. Postmortem validation of breast density using dual-energy mammography

    International Nuclear Information System (INIS)

    Molloi, Sabee; Ducote, Justin L.; Ding, Huanjun; Feig, Stephen A.

    2014-01-01

    Purpose: Mammographic density has been shown to be an indicator of breast cancer risk and also reduces the sensitivity of screening mammography. Currently, there is no accepted standard for measuring breast density. Dual energy mammography has been proposed as a technique for accurate measurement of breast density. The purpose of this study is to validate its accuracy in postmortem breasts and compare it with other existing techniques. Methods: Forty postmortem breasts were imaged using a dual energy mammography system. Glandular and adipose equivalent phantoms of uniform thickness were used to calibrate a dual energy basis decomposition algorithm. Dual energy decomposition was applied after scatter correction to calculate breast density. Breast density was also estimated using radiologist reader assessment, standard histogram thresholding and a fuzzy C-mean algorithm. Chemical analysis was used as the reference standard to assess the accuracy of different techniques to measure breast composition. Results: Breast density measurements using radiologist reader assessment, standard histogram thresholding, fuzzy C-mean algorithm, and dual energy were in good agreement with the measured fibroglandular volume fraction using chemical analysis. The standard error estimates using radiologist reader assessment, standard histogram thresholding, fuzzy C-mean, and dual energy were 9.9%, 8.6%, 7.2%, and 4.7%, respectively. Conclusions: The results indicate that dual energy mammography can be used to accurately measure breast density. The variability in breast density estimation using dual energy mammography was lower than reader assessment rankings, standard histogram thresholding, and fuzzy C-mean algorithm. Improved quantification of breast density is expected to further enhance its utility as a risk factor for breast cancer

  9. Can positron emission mammography help to identify clinically significant breast cancer in women with suspicious calcifications on mammography?

    Energy Technology Data Exchange (ETDEWEB)

    Bitencourt, Almir G.V.; Lima, Eduardo N.P.; Macedo, Bruna R.C.; Conrado, Jorge L.F.A.; Marques, Elvira F.; Chojniak, Rubens [A C Camargo Cancer Center-Department of Imaging, Sao Paulo, SP (Brazil)

    2017-05-15

    To evaluate the diagnostic accuracy of positron emission mammography (PEM) for identifying malignant lesions in patients with suspicious microcalcifications detected on mammography. A prospective, single-centre study that evaluated 40 patients with suspicious calcifications at mammography and indication for percutaneous or surgical biopsy, with mean age of 56.4 years (range: 28-81 years). Patients who agreed to participate in the study underwent PEM with 18F-fluorodeoxyglucose before the final histological evaluation. PEM findings were compared with mammography and histological findings. Most calcifications (n = 34; 85.0 %) were classified as BIRADS 4. On histology, there were 25 (62.5 %) benign and 15 (37.5 %) malignant lesions, including 11 (27.5 %) ductal carcinoma in situ (DCIS) and 4 (10 %) invasive carcinomas. On subjective analysis, PEM was positive in 15 cases (37.5 %) and most of these cases (n = 14; 93.3 %) were confirmed as malignant on histology. There was one false-positive result, which corresponded to a fibroadenoma, and one false negative, which corresponded to an intermediate-grade DCIS. PEM had a sensitivity of 93.3 %, specificity of 96.0 % and accuracy of 95 %. PEM was able to identify all invasive carcinomas and high-grade DCIS (nuclear grade 3) in the presented sample, suggesting that this method may be useful for further evaluation of patients with suspected microcalcifications. (orig.)

  10. Discriminating solitary cysts from soft tissue lesions in mammography using a pretrained deep convolutional neural network.

    Science.gov (United States)

    Kooi, Thijs; van Ginneken, Bram; Karssemeijer, Nico; den Heeten, Ard

    2017-03-01

    It is estimated that 7% of women in the western world will develop palpable breast cysts in their lifetime. Even though cysts have been correlated with risk of developing breast cancer, many of them are benign and do not require follow-up. We develop a method to discriminate benign solitary cysts from malignant masses in digital mammography. We think a system like this can have merit in the clinic as a decision aid or complementary to specialized modalities. We employ a deep convolutional neural network (CNN) to classify cyst and mass patches. Deep CNNs have been shown to be powerful classifiers, but need a large amount of training data for which medical problems are often difficult to come by. The key contribution of this paper is that we show good performance can be obtained on a small dataset by pretraining the network on a large dataset of a related task. We subsequently investigate the following: (a) when a mammographic exam is performed, two different views of the same breast are recorded. We investigate the merit of combining the output of the classifier from these two views. (b) We evaluate the importance of the resolution of the patches fed to the network. (c) A method dubbed tissue augmentation is subsequently employed, where we extract normal tissue from normal patches and superimpose this onto the actual samples aiming for a classifier invariant to occluding tissue. (d) We combine the representation extracted using the deep CNN with our previously developed features. We show that using the proposed deep learning method, an area under the ROC curve (AUC) value of 0.80 can be obtained on a set of benign solitary cysts and malignant mass findings recalled in screening. We find that it works significantly better than our previously developed approach by comparing the AUC of the ROC using bootstrapping. By combining views, the results can be further improved, though this difference was not found to be significant. We find no significant difference between

  11. Meta-analysis of breast cancer mortality benefit and overdiagnosis adjusted for adherence: improving information on the effects of attending screening mammography

    Science.gov (United States)

    Jacklyn, Gemma; Glasziou, Paul; Macaskill, Petra; Barratt, Alexandra

    2016-01-01

    Background: Women require information about the impact of regularly attending screening mammography on breast cancer mortality and overdiagnosis to make informed decisions. To provide this information we aimed to meta-analyse randomised controlled trials adjusted for adherence to the trial protocol. Methods: Nine screening mammography trials used in the Independent UK Breast Screening Report were selected. Extending an existing approach to adjust intention-to-treat (ITT) estimates for less than 100% adherence rates, we conducted a random-effects meta-analysis. This produced a combined deattenuated prevented fraction and a combined deattenuated percentage risk of overdiagnosis. Results: In women aged 39–75 years invited to screen, the prevented fraction of breast cancer mortality at 13-year follow-up was 0.22 (95% CI 0.15–0.28) and it increased to 0.30 (95% CI 0.18–0.42) with deattenuation. In women aged 40–69 years invited to screen, the ITT percentage risk of overdiagnosis during the screening period was 19.0% (95% CI 15.2–22.7%), deattenuation increased this to 29.7% (95% CI 17.8–41.5%). Conclusions: Adjustment for nonadherence increased the size of the mortality benefit and risk of overdiagnosis by up to 50%. These estimates are more appropriate when developing quantitative information to support individual decisions about attending screening mammography. PMID:27124337

  12. Metric regularity and subdifferential calculus

    International Nuclear Information System (INIS)

    Ioffe, A D

    2000-01-01

    The theory of metric regularity is an extension of two classical results: the Lyusternik tangent space theorem and the Graves surjection theorem. Developments in non-smooth analysis in the 1980s and 1990s paved the way for a number of far-reaching extensions of these results. It was also well understood that the phenomena behind the results are of metric origin, not connected with any linear structure. At the same time it became clear that some basic hypotheses of the subdifferential calculus are closely connected with the metric regularity of certain set-valued maps. The survey is devoted to the metric theory of metric regularity and its connection with subdifferential calculus in Banach spaces

  13. Manifold Regularized Correlation Object Tracking.

    Science.gov (United States)

    Hu, Hongwei; Ma, Bo; Shen, Jianbing; Shao, Ling

    2018-05-01

    In this paper, we propose a manifold regularized correlation tracking method with augmented samples. To make better use of the unlabeled data and the manifold structure of the sample space, a manifold regularization-based correlation filter is introduced, which aims to assign similar labels to neighbor samples. Meanwhile, the regression model is learned by exploiting the block-circulant structure of matrices resulting from the augmented translated samples over multiple base samples cropped from both target and nontarget regions. Thus, the final classifier in our method is trained with positive, negative, and unlabeled base samples, which is a semisupervised learning framework. A block optimization strategy is further introduced to learn a manifold regularization-based correlation filter for efficient online tracking. Experiments on two public tracking data sets demonstrate the superior performance of our tracker compared with the state-of-the-art tracking approaches.

  14. Dimensional regularization in configuration space

    International Nuclear Information System (INIS)

    Bollini, C.G.; Giambiagi, J.J.

    1995-09-01

    Dimensional regularization is introduced in configuration space by Fourier transforming in D-dimensions the perturbative momentum space Green functions. For this transformation, Bochner theorem is used, no extra parameters, such as those of Feynman or Bogoliubov-Shirkov are needed for convolutions. The regularized causal functions in x-space have ν-dependent moderated singularities at the origin. They can be multiplied together and Fourier transformed (Bochner) without divergence problems. The usual ultraviolet divergences appear as poles of the resultant functions of ν. Several example are discussed. (author). 9 refs

  15. Regular algebra and finite machines

    CERN Document Server

    Conway, John Horton

    2012-01-01

    World-famous mathematician John H. Conway based this classic text on a 1966 course he taught at Cambridge University. Geared toward graduate students of mathematics, it will also prove a valuable guide to researchers and professional mathematicians.His topics cover Moore's theory of experiments, Kleene's theory of regular events and expressions, Kleene algebras, the differential calculus of events, factors and the factor matrix, and the theory of operators. Additional subjects include event classes and operator classes, some regulator algebras, context-free languages, communicative regular alg

  16. Matrix regularization of 4-manifolds

    OpenAIRE

    Trzetrzelewski, M.

    2012-01-01

    We consider products of two 2-manifolds such as S^2 x S^2, embedded in Euclidean space and show that the corresponding 4-volume preserving diffeomorphism algebra can be approximated by a tensor product SU(N)xSU(N) i.e. functions on a manifold are approximated by the Kronecker product of two SU(N) matrices. A regularization of the 4-sphere is also performed by constructing N^2 x N^2 matrix representations of the 4-algebra (and as a byproduct of the 3-algebra which makes the regularization of S...

  17. A study of some technical essentials of X-ray mammography

    International Nuclear Information System (INIS)

    Cao Houde; Jiang Qin

    2000-01-01

    Objective: To improve the quality of mammography and diagnostic accuracy by analyzing and studying some of the technical essentials of X-ray mammography. Methods: The mammography quality of 21 hospitals were investigated. The image quality of normal intensifying screen-film combination was tested and compared with computerized mammography. The filming positions and operating skills were studied. Results: The important mammography details that were displayed have low conformity with the diagnostic requirements, mainly due to non-conformity of these equipment to the requirements. The optimal pressure suitable for mammography of the Chinese women was around 12 kg. Conclusion: Necessary attention must be paid to the improvement of imaging features of these equipment. The improved operating skills will greatly raise the detecting percentage of pathological changes of breasts

  18. Image quality and radiation exposure in digital storage plate mammography with magnification technique

    International Nuclear Information System (INIS)

    Fiedler, E.; Aichinger, U.; Boehner, C.; Schulz-Wendtland, R.; Bautz, W.; Saebel, M.

    1999-01-01

    Purpose: Comparison of image quality between digital phosphor storage plate mammography in magnification technique and a conventional film screen system regarding the special aspect of radiation exposure. Materials and Methods: Radiograms of a RMI-mammography phantom were acquired using a conventional film screen system and two digital storage plate systems. Additionally, the radiograms of one digital system were postprocessed emphasizing contrast and included in the comparison. Results: The detectability of details in storage plate mammographies with magnification technique is almost equal to that of film screen mammographies. Thereby, lower radiation exposures were necessary using the digital systems. Conclusions: Based on these results, storage plate mammography in magnification technique is used in clinical routine at our institution. The correct parameters in image postprocessing are of elementary importance for detail detectability. Future studies must show, whether the lower radiation exposure in digital radiograms of the breast, revealing much higher background noise, will allow the same detail detectability as film screen mammographies. (orig.) [de

  19. Doses mammography: from phantom to the patient

    Energy Technology Data Exchange (ETDEWEB)

    Cross, P [Gammasonic Radiological Services, Pty., Ltd., Five Dock, NSW (Australia)

    1994-02-01

    While the use of a reference phantom is essential for dosimetry in acceptance testing and in regular quality control checks of a mammographic X-ray unit, it is also of importance to be able to estimate the patient dose in each individual investigation. Radiographic and physical data were analysed for a total of 212 women who were screened at three locations participating in a breast screening programme. The radiologists made estimates of the individual breast composition (%glandular/adipose ratio) at the film reporting sessions, and then the glandular doses were calculated by the auditor according to the NCRP 85 methodology. Arising from the data analysis of this dosimetry survey, a method is proposed to determine objectively patient breast composition from the photo-timed mAs for a given film optical density setting. This permits the NCRP calculations to be extended from breasts of 'average' (50/50) composition to breasts of individually determined composition. The diversity of the results between the three locations emphasises the need for regular audits of a mammographic X-ray unit's performance by an experienced radiological physicists, at least annually or after any major interventional service on the unit. 11 refs., 6 tabs., 4 figs.

  20. Regularization of Nonmonotone Variational Inequalities

    International Nuclear Information System (INIS)

    Konnov, Igor V.; Ali, M.S.S.; Mazurkevich, E.O.

    2006-01-01

    In this paper we extend the Tikhonov-Browder regularization scheme from monotone to rather a general class of nonmonotone multivalued variational inequalities. We show that their convergence conditions hold for some classes of perfectly and nonperfectly competitive economic equilibrium problems

  1. Lattice regularized chiral perturbation theory

    International Nuclear Information System (INIS)

    Borasoy, Bugra; Lewis, Randy; Ouimet, Pierre-Philippe A.

    2004-01-01

    Chiral perturbation theory can be defined and regularized on a spacetime lattice. A few motivations are discussed here, and an explicit lattice Lagrangian is reviewed. A particular aspect of the connection between lattice chiral perturbation theory and lattice QCD is explored through a study of the Wess-Zumino-Witten term

  2. 76 FR 3629 - Regular Meeting

    Science.gov (United States)

    2011-01-20

    ... Meeting SUMMARY: Notice is hereby given of the regular meeting of the Farm Credit System Insurance Corporation Board (Board). Date and Time: The meeting of the Board will be held at the offices of the Farm... meeting of the Board will be open to the [[Page 3630

  3. Forcing absoluteness and regularity properties

    NARCIS (Netherlands)

    Ikegami, D.

    2010-01-01

    For a large natural class of forcing notions, we prove general equivalence theorems between forcing absoluteness statements, regularity properties, and transcendence properties over L and the core model K. We use our results to answer open questions from set theory of the reals.

  4. Globals of Completely Regular Monoids

    Institute of Scientific and Technical Information of China (English)

    Wu Qian-qian; Gan Ai-ping; Du Xian-kun

    2015-01-01

    An element of a semigroup S is called irreducible if it cannot be expressed as a product of two elements in S both distinct from itself. In this paper we show that the class C of all completely regular monoids with irreducible identity elements satisfies the strong isomorphism property and so it is globally determined.

  5. Fluid queues and regular variation

    NARCIS (Netherlands)

    Boxma, O.J.

    1996-01-01

    This paper considers a fluid queueing system, fed by N independent sources that alternate between silence and activity periods. We assume that the distribution of the activity periods of one or more sources is a regularly varying function of index ¿. We show that its fat tail gives rise to an even

  6. Fluid queues and regular variation

    NARCIS (Netherlands)

    O.J. Boxma (Onno)

    1996-01-01

    textabstractThis paper considers a fluid queueing system, fed by $N$ independent sources that alternate between silence and activity periods. We assume that the distribution of the activity periods of one or more sources is a regularly varying function of index $zeta$. We show that its fat tail

  7. Empirical laws, regularity and necessity

    NARCIS (Netherlands)

    Koningsveld, H.

    1973-01-01

    In this book I have tried to develop an analysis of the concept of an empirical law, an analysis that differs in many ways from the alternative analyse's found in contemporary literature dealing with the subject.

    1 am referring especially to two well-known views, viz. the regularity and

  8. Interval matrices: Regularity generates singularity

    Czech Academy of Sciences Publication Activity Database

    Rohn, Jiří; Shary, S.P.

    2018-01-01

    Roč. 540, 1 March (2018), s. 149-159 ISSN 0024-3795 Institutional support: RVO:67985807 Keywords : interval matrix * regularity * singularity * P-matrix * absolute value equation * diagonally singilarizable matrix Subject RIV: BA - General Mathematics Impact factor: 0.973, year: 2016

  9. Regularization in Matrix Relevance Learning

    NARCIS (Netherlands)

    Schneider, Petra; Bunte, Kerstin; Stiekema, Han; Hammer, Barbara; Villmann, Thomas; Biehl, Michael

    A In this paper, we present a regularization technique to extend recently proposed matrix learning schemes in learning vector quantization (LVQ). These learning algorithms extend the concept of adaptive distance measures in LVQ to the use of relevance matrices. In general, metric learning can

  10. Review and analysis of mammographies of Servicio de Radiologia Hospital San Juan de Dios

    International Nuclear Information System (INIS)

    Araya Cerdas, Adrian; Mirambell Sanchez, Melania; Monge Vega, Mandred; Mora Vargas, Karla; Vega Aguilar, Laura

    2013-01-01

    The concept of mammography is defined. The mammography has been estimated as the best tool currently available for the detection of breast cancer in its early stages, in addition, have been detected clinically occult lesions. Mammographies of the Servicio de Radiologia Hospital San Juan de Dios were analyzed for a total of 1250. The findings were related as static between BIRADS categorization and inherited-family factors, geographical and personal pathological of patients treated in the period September 2012 to January 2013 [es

  11. Quality control: comparison of images quality with screen film system and digital mammography CR

    International Nuclear Information System (INIS)

    Alvarenga, Frederico L.; Nogueira, Maria do Socorro

    2008-01-01

    The mammography screen film system should be used as part of processing chemicals, revelation process, equipment and this system has have a progressive replacing by the digital technology Full Field Digital Mammography FFDM, Computed Radiography (CR) Mammography and hardcopy. This new acquisition process of medical images has improved radiology section; however it is necessary efficient means for evaluating of the quality parameters. It should be considered taking into account the adaptation of the existent equipment and that procedures adopted for the exam, as well the adaptation of the new mammography films, the radiologist view box constitutes a part of the quality control program. This program aims at obtaining radiography with good quality that allows obtaining more information for the diagnosis and decreases the patient dose. For evaluation the quality image, this article is focused on presenting the differences regarding the acquired images through simulator mammography radiographic PMMA (Poly methyl methacrylate) in CR Mammography system and screen film system. The tests were accomplished at the same equipment of Mammography with the Automatic Exposure Control using a tension of 28 kV for both systems. The quality tests evaluated the spatial resolution, the own structures of the phantom, artifacts, optical density and contrast with conventional and laser films by mammography system. The installation for the accomplishment of the test has a quality control program. The evaluation was based on the pattern developed by the competent organ of the State of Minas Gerais. In this study, it was verified that the suitable Phantom Mama used by the Brazilian School of Radiology for conventional mammography did not obtain satisfactory result for Spatial Resolution in the digital mammography system CR. The final aim of this work is to obtain parameters to characterize the reference phantom quality image in an objective way. These parameters will be used to compare

  12. Atlas and toolbook of MR mammography; Lehratlas der MR-Mammographie

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, U. [Universitaetsklinikum Goettingen (Germany). Abt. Roentgendiagnostik I; Brinck, U. [Universitaetsklinikum Goettingen (Germany). Abt. Pathologie und Pathologische Anatomie

    2000-07-01

    This richly illustrated toolbook and atlas contains information on all aspects of nmr diagnostic imaging of benign or malignant neoplasms of female and male mammary glands. It offers pinpointed guidance and insight for vocational training and continuing training of radiology assistants, students and medical radiologists. (orig./AJ) [German] Die MRT als hochaufloesendes und schaedigungsfreies Diagnostikum gewinnt gerade in der emotional stark besetzten Mammadiagnostik zunehmend an Bedeutung. Dennoch beherrschen nur wenige Zentren im deutschsprachigen Raum diese Technik, die - eine hohe Reproduzierbarkeit bei fehlender Belastung fuer die Patientin bietet, - invasive Karzinome bereits ab einer Groesse von 5 mm mit hoher Zuverlaessigkeit ausschliessen kann und - gerade bei widerspruechlichen Befunden zwischen klinischer Untersuchung, Roentgenmammographie und perkutaner Biopsie eine wesentliche Entscheidungshilfe bieten kann. Aus einem der fuehrenden Zentren in der MR-Mammographie wurde daher dieser praxisnahe, opulent ausgestattete und weit ueber die reine Bildinformation hinausgehende 'Einstiegs- und Lehratlas' entwickelt. Er bietet Radiologen in Fort- und Weiterbildung, aber auch Gynaekologen mit ueber 400 Abbildungen klare Antworten auf die Fragen. (orig./AJ)

  13. Regular and conformal regular cores for static and rotating solutions

    Energy Technology Data Exchange (ETDEWEB)

    Azreg-Aïnou, Mustapha

    2014-03-07

    Using a new metric for generating rotating solutions, we derive in a general fashion the solution of an imperfect fluid and that of its conformal homolog. We discuss the conditions that the stress–energy tensors and invariant scalars be regular. On classical physical grounds, it is stressed that conformal fluids used as cores for static or rotating solutions are exempt from any malicious behavior in that they are finite and defined everywhere.

  14. Regular and conformal regular cores for static and rotating solutions

    International Nuclear Information System (INIS)

    Azreg-Aïnou, Mustapha

    2014-01-01

    Using a new metric for generating rotating solutions, we derive in a general fashion the solution of an imperfect fluid and that of its conformal homolog. We discuss the conditions that the stress–energy tensors and invariant scalars be regular. On classical physical grounds, it is stressed that conformal fluids used as cores for static or rotating solutions are exempt from any malicious behavior in that they are finite and defined everywhere.

  15. Breast cancer imaging: Mammography among women of up to 45 years

    International Nuclear Information System (INIS)

    Schnejder-Wilk, A.

    2010-01-01

    Background: Among women under the age of 40, screening mammography examinations are not performed routinely. An ultrasonography scan is considered to be a basic breast imaging examination among younger women. The purpose of this study was to analyze mammography images, as well as to evaluate the usefulness and role of mammography in breast cancer diagnostic processes in women of up to 45 years, based on own experience. Material/Methods: A retrospective analysis of mammography images, including 144 cases of breast cancer diagnosed in the group of 140 women of 45 years of age. All the patients underwent pre-treatment mammography and surgery procedure. The images were evaluated in accordance to BIRADS criteria. Lesions detectable in mammography were grouped as follows: spiculated mass; nonmicrocalcified oval/round mass; microcalcified mass (regardless of shape); microcalcifications; architectural distortion; breast tissue asymmetry. Results: The most common mammographic symptom was solid tumor (41%), followed by microcalcified tumors (20.8%). Clusters of microcalcifications constituted 17.4% of mammography findings. In 4.9% of mammography scans, examination did not reveal any pathological lesions. Conclusions: Breast cancer mammograms of women aged up to 45 years do not differ from diagnostic pictures of breast cancer in older women. The diagnostic appearance of breast cancer in 1/3 of the patients involved microcalcifications detectable only on mammograms. All the women with suspicion of breast cancer should have their mammography examinations performed, irrespective of ultrasonography scans. (author)

  16. Contrast-enhanced spectral mammography in patients referred from the breast cancer screening programme.

    Science.gov (United States)

    Lobbes, Marc B I; Lalji, Ulrich; Houwers, Janneke; Nijssen, Estelle C; Nelemans, Patty J; van Roozendaal, Lori; Smidt, Marjolein L; Heuts, Esther; Wildberger, Joachim E

    2014-07-01

    Feasibility studies have shown that contrast-enhanced spectral mammography (CESM) increases diagnostic accuracy of mammography. We studied diagnostic accuracy of CESM in patients referred from the breast cancer screening programme, who have a lower disease prevalence than previously published papers on CESM. During 6 months, all women referred to our hospital were eligible for CESM. Two radiologists blinded to the final diagnosis provided BI-RADS classifications for conventional mammography and CESM. Statistical significance of differences between mammography and CESM was calculated using McNemar's test. Receiver operating characteristic (ROC) curves were constructed for both imaging modalities. Of the 116 eligible women, 113 underwent CESM. CESM increased sensitivity to 100.0% (+3.1%), specificity to 87.7% (+45.7%), PPV to 76.2% (+36.5%) and NPV to 100.0% (+2.9%) as compared to mammography. Differences between conventional mammography and CESM were statistically significant (p mammography, AUC was 0.779. With CESM, AUC increased to 0.976 (p mammography, even in lower prevalence patient populations such as referrals from breast cancer screening. • CESM is feasible in the workflow of referrals from routine breast screening. • CESM is superior to mammography, even in low disease prevalence populations. • CESM has an extremely high negative predictive value for breast cancer. • CESM is comparable to MRI in assessment of breast cancer extent. • CESM is comparable to histopathology in assessment of breast cancer extent.

  17. Mammography in breast screening and in the evaluation and management of breast cancer

    International Nuclear Information System (INIS)

    Onyesoh, C.N.

    2006-01-01

    This paper aims to discuss the importance of breast screening most especially amongst women above the age of 40 years.the limitation of the screening procedure is due to lack of special machines and power awareness campaigns. the application of Mammography and ultrasound in the examination of the breast and other breast imaging techniques will be considered in this paper. The paper will look at the indications for mammography, indications for breast ultrasound, signs of breast carcinoma on mammography, breast enlargement and also the need for breast ultrasound in cases of discrete Mammography

  18. Measurement of half-value layer in mammography

    CERN Document Server

    Yagi, H; Saruwatari, R; Doi, N; Yamane, E

    2003-01-01

    The half-value layer (HVL) of an X-ray beam for film-screen mammography is considered an important parameter for image quality and patient dose. Thus, HVL must be measured in accordance with The Manual of Accuracy for Mammography printed by the Japanese Society of Radiological Technology. The manual prescribes exactly the geometry of measurement, chamber position of measurement in the field, selection of chamber, and so on. However, the measurement of HVL is difficult in the actual clinical setting. This study examined the results of failure to perform the measurement of HVL in accordance with the manual for measuring HVL in the clinical setting. The investigation indicated that serious problems do not arise when measuring HVL for routine quality control even if the chamber in the field is not always set according to the manual and if a chamber for radiotherapy or diagnosis is used that is not recommended for soft X-ray by the manual. (author)

  19. Radiation dose in mammography: an energy-balance approach

    International Nuclear Information System (INIS)

    Shrivastava, P.N.

    1981-01-01

    An energy-balance approach for calculation of mean, integral, and midpoint doses in mammography is introduced. Estimation of mean absorbed dose for individual applications is described. Calculations made for a range of xeromammographic techniques used at various breast cancer detection centers show that although increasing the beam h.v.l. dramatically decreases breast surface exposure, it is insignificant in lowering mean breast dose or radiation risk. Thus selection of a moderate h.v.l. to optimize image quality in xeromammography may be more beneficial than unduly increasing h.v.l. merely to reduce surface exposure. The mean breast dose per mammogram with low h.v.l. screen-film techniques was 3 to 9 times lower than for xeromammography, suggesting that general acceptance of screen-film techniques can significantly reduce the risk associated with mammography

  20. Radiation dose in mammography: an energy-balance approach

    International Nuclear Information System (INIS)

    Shrivastava, P.N.

    1981-01-01

    An energy-balance approach for calculation of mean, integral, and midpoint doses in mammography is introduced. Estimation of mean absorbed dose for individual applications is described. Differences in breast composition and thickness are accounted for by simple measurements of entrance and exit exposures. Calculations made for a range of xeromammographic techniques used at various breast cancer detection centers show that although increasing the beam h.v.l. dramatically decreases breast surface exposure, it is insignificant in lowering mean breast dose or radiation risk. Thus selection of a moderate h.v.l. to optimize image quality (soft-tissue contrast) in xeromammography may be more beneficial than unduly increasing h.v.l. merely to reduce surface exposure. The mean breast dose per mammogram with low-h.v.l. screen-film techniques was 3 to 9 times lower than for xeromammography, suggesting that general acceptance of screen-film techniques can significantly reduce the risk associated with mammography

  1. An SVM Based Approach for the Analysis Of Mammography Images

    Science.gov (United States)

    Gan, X.; Kapsokalivas, L.; Skaliotis, A.; Steinhöfel, K.; Tangaro, S.

    2007-09-01

    Mammography is among the most popular imaging techniques used in the diagnosis of breast cancer. Nevertheless distinguishing between healthy and ill images is hard even for an experienced radiologist, because a single image usually includes several regions of interest (ROIs). The hardness of this classification problem along with the substantial amount of data, gathered from patients' medical history, motivates the use of a machine learning approach as part of a CAD (Computer Aided Detection) tool, aiming to assist radiologists in the characterization of mammography images. Specifically, our approach involves: i) the ROI extraction, ii) the Feature Vector extraction, iii) the Support Vector Machine (SVM) classification of ROIs and iv) the characterization of the whole image. We evaluate the performance of our approach in terms of the SVM's training and testing error and in terms of ROI specificity—sensitivity. The results show a relation between the number of features used and the SVM's performance.

  2. An SVM Based Approach for the Analysis Of Mammography Images

    International Nuclear Information System (INIS)

    Gan, X.; Kapsokalivas, L.; Skaliotis, A.; Steinhoefel, K.; Tangaro, S.

    2007-01-01

    Mammography is among the most popular imaging techniques used in the diagnosis of breast cancer. Nevertheless distinguishing between healthy and ill images is hard even for an experienced radiologist, because a single image usually includes several regions of interest (ROIs). The hardness of this classification problem along with the substantial amount of data, gathered from patients' medical history, motivates the use of a machine learning approach as part of a CAD (Computer Aided Detection) tool, aiming to assist radiologists in the characterization of mammography images. Specifically, our approach involves: i) the ROI extraction, ii) the Feature Vector extraction, iii) the Support Vector Machine (SVM) classification of ROIs and iv) the characterization of the whole image. We evaluate the performance of our approach in terms of the SVM's training and testing error and in terms of ROI specificity - sensitivity. The results show a relation between the number of features used and the SVM's performance

  3. Latin American image quality survey in digital mammography studies

    International Nuclear Information System (INIS)

    Mora, Patricia; Khoury, Helen; Bitelli, Regina; Quintero, Ana Rosa; Garay, Fernando; Garcia Aguilar, Juan; Gamarra, Mirtha; Ubeda, Carlos

    2017-01-01

    Under International Atomic Energy Agency regional programme TSA3 Radiological Protection of Patients in Medical Exposures, Latin American countries evaluated the image quality and glandular doses for digital mammography equipment with the purpose of seeing the performance and compliance with international recommendations. Totally, 24 institutions participated from Brazil, Chile, Costa Rica, El Salvador, Mexico, Paraguay and Venezuela. Signal difference noise ratio results showed for CR poor compliance with tolerances; better results were obtained for full-field digital mammography equipment. Mean glandular dose results showed that the majority of units have values below the acceptable dose levels. This joint Latin American project identified common problems: difficulty in working with digital images and lack of specific training by medical physicists from the region. Image quality is a main issue not being satisfied in accordance with international recommendations; optimisation processes in which the doses are increased should be very carefully done in order to improve early detection of any cancer signs. (authors)

  4. Value of mammography in the early detection of breast cancer

    International Nuclear Information System (INIS)

    Sabate, J.; Molina, L.; Jimenez, A.; Fernandez, E.

    1997-01-01

    Breast cancer is the most prevalent malignant tumor in women; the etiopathogenesis is unknown and it is associated with high rates of morbidity and mortality. In the fifties, different screening programs were developed for the early detection of breast cancer in the attempt to reduce the mortality attributed to this disease process. Mammography is one of the cornerstones of these programs because of its efficacy in the detection of subclinical tumors. We carried out a retrospective review of nine campaigns for the early detection of breast cancer, studying 11, 328 case reports; among these patients, there were 43 cases of breast cancer. Mammography was positive in 90.6% of these cases. Only in two patients did the image fail to reveal changes indicative of possible neoplasm; in both cases, the breasts involved were very dense. (Author) 26 refs

  5. Screening mammography in women 65 years old and older

    International Nuclear Information System (INIS)

    Rubin, E.; Mulligan, S.A.; Han, S.Y.; Bernreuter, W.K.; Stanley, R.J.

    1990-01-01

    This paper compares the results of mammographic screening in women aged 65 years and older to those of women aged 50--64 years, to define risk factors and prior use of mammography in these women, and to determine whether mammographic abnormalities are managed differently in the two age groups. Historical data, mammographic findings, and biopsy results were analyzed for all women over 50 years of age screened during 1988 (2,862 patients) at a university hospital-based outpatient center and mobile van, excluding those referred by oncologists. The following factors were determined for patients screened at the outpatient center and the mobile van, with both groups divided according to patient age (50--64 vs ≥ 65 years): presence of risk factors, previous biopsy, exogenous hormones, percentage of black patients, previous mammography, biopsy rate, cancer detection rate, positive nodes, and presence of tumors smaller than 1 cm or ductal carcinoma in-situ

  6. Diagnostic Invasiveness and Psychosocial Consequences of False-Positive Mammography

    DEFF Research Database (Denmark)

    Heleno, Bruno M.; Siersma, Volkert Dirk; Brodersen, John

    2015-01-01

    PURPOSE: We undertook a study to assess whether women with false-positivemammography have worse psychosocial consequences if managed with aworkup that involves a biopsy (invasive group) than if managed with only additional imaging (noninvasive group). METHODS: We performed subgroup analysis...... of a cohort study of 454 womenwith abnormal screening mammography and 908 matched control women withnormal results. Using a condition-specific questionnaire (Consequences of Screening in Breast Cancer), we assessed 12 psychosocial consequences at 5 time points (0, 1, 6, 18, and 36 months after final diagnosis......) and compared the 2 groups of women with false-positives (invasive and noninvasive management groups). RESULTS: Among the 252 women with false-positive mammography eligible forthis study, psychosocial consequences were similar for those managed invasivelyand those managed noninvasively during the 36 months...

  7. Selective photon counter for digital x-ray mammography tomosynthesis

    Science.gov (United States)

    Goldan, Amir H.; Karim, Karim S.; Rowlands, J. A.

    2006-03-01

    Photon counting is an emerging detection technique that is promising for mammography tomosynthesis imagers. In photon counting systems, the value of each image pixel is equal to the number of photons that interact with the detector. In this research, we introduce the design and implementation of a low noise, novel selective photon counting pixel for digital mammography tomosynthesis in crystalline silicon CMOS (complementary metal oxide semiconductor) 0.18 micron technology. The design comprises of a low noise charge amplifier (CA), two low offset voltage comparators, a decision-making unit (DMU), a mode selector, and a pseudo-random counter. Theoretical calculations and simulation results of linearity, gain, and noise of the photon counting pixel are presented.

  8. The results of a quality-control programme in mammography

    International Nuclear Information System (INIS)

    Ramsdale, M.L.; Hiles, P.A.

    1989-01-01

    With the introduction of a breast screening programme in the UK, quality assurance in mammography is of paramount importance in assuring optimum imaging performance with low dose. Quality control checks are an essential part of the quality-assurance system. A quality-control programme at a breast screening clinic is described. Daily checks include film sensitometry for X-ray processor control and radiography of a lucite phantom to monitor the consistency of the X-ray machine automatic exposure control. Weekly checks include additional measurements on the performance of the automatic exposure control for different breast thickness and an overall assessment of image quality using a prototype mammography test phantom. The test phantom measures low-contrast sensitivity, high-contrast resolution and small-detail visibility. The results of the quality-control programme are presented with particular attention paid to tolerances and limiting values. (author)

  9. Information on mammography-screening - from deception to insight

    International Nuclear Information System (INIS)

    Muehlhauser, I.; Hoeldke, B.

    2002-01-01

    Information about mammography-screening as a basis for informed-decision making has to be evidence-based and presented in an unbiased format. This includes communication of results about effectiveness/lack of effectiveness of screening programmes (breast cancer mortality, total mortality), the quality of mammography as a screening test (sensitivity, specificity, positive and negative predictive values), and possible harm (consequences of false positive and false negative results, overdiagnosis of breast cancer, overtreatment). Outcome data have to be communicated as natural frequencies rather than relative differences. In order to avoid framing of data equal emphasis has to be put on the proportion of persons who are likely to benefit and those who are unlikely to benefit or likely to be harmed. (orig.) [de

  10. Diagnostic reference levels in digital mammography: a systematic review

    International Nuclear Information System (INIS)

    Suleiman, Moayyad E.; Brennan, Patrick C.; McEntee, Mark F.

    2015-01-01

    This study aims to review the literature on existing diagnostic reference levels (DRLs) in digital mammography and methodologies for establishing them. To this end, a systematic search through Medline, Cinahl, Web of Science, Scopus and Google scholar was conducted using search terms extracted from three terms: DRLs, digital mammography and breast screen. The search resulted in 1539 articles of which 22 were included after a screening process. Relevant data from the included studies were summarised and analysed. Differences were found in the methods utilised to establish DRLs including test subjects types, protocols followed, conversion factors employed, breast compressed thicknesses and percentile values adopted. These differences complicate comparison of DRLs among countries; hence, an internationally accepted protocol would be valuable so that international comparisons can be made. (authors)

  11. Volumetric breast density affects performance of digital screening mammography

    OpenAIRE

    Wanders, JO; Holland, K; Veldhuis, WB; Mann, RM; Pijnappel, RM; Peeters, PH; Van Gils, CH; Karssemeijer, N

    2016-01-01

    PURPOSE: To determine to what extent automatically measured volumetric mammographic density influences screening performance when using digital mammography (DM). METHODS: We collected a consecutive series of 111,898 DM examinations (2003-2011) from one screening unit of the Dutch biennial screening program (age 50-75 years). Volumetric mammographic density was automatically assessed using Volpara. We determined screening performance measures for four density categories comparable to the Ameri...

  12. Radiation dose during mammography using various recording systems

    International Nuclear Information System (INIS)

    Heep, H.; Buelow-Johansen, T.; Klemencic, J.; Wegwitz, J.; Stadtkrankenhaus Offenbach

    1978-01-01

    Patient dose during mammography for various recording systems, such as film, film-screen combination and xeromammography was measured by thermoluminescent densitometers. In the first set of experiments we measured dose per exposure, in a second set total surface dose at five points on the breast, using the following combintions: a) Two industrial film exposures and one xeromammographic exposure. b) two film-screen exposures and one xeromammographic exposure. c) One industrial film and two xeromammographic exposures. (orig.) [de

  13. Indicators of image quality and doses in mammography

    International Nuclear Information System (INIS)

    Gaona, E.; Franco E, J.G.; Azorin N, J.; Diaz G, J.A.I.; Arreola, M.

    2007-01-01

    Full text: The purpose of the study was to determine the values of the image quality indicators and their relationship with the dose in mammography of screen-film that they allowed the detection of a bigger number of objects in the images obtained with the mannequin (phantom) authorized of the ACR/FDA. The study was carried out in four mammography services in a period of 12 months. The indicators of the image quality are the half optic density (DOM), contrast (differences of densities), the number of observed objects in the images and the dose for image. The minimum acceptable values by the ACR/FDA are a half optical density of 1.4, contrast of 0.4 and the one numbers minimum of objects observed in the image of the mannequin of mammography of 10 (4 fibers, 3 groups of calcifications and 3 masses), with a maximum dose by image of 3 mGy. The found results are half optical density of 1.9, contrast of 0.56 and the average number of objects observed in the images of 12, with a dose in the interval of 1.6 mGy to 2.4 mGy. The doses were measured by thermoluminescent dosimetry and ionization chamber. Once carried out the analysis of the tendencies of the indicators of image quality and their distributions is found that for a p < 0.05, the bigger number of objects observed in the images is in the interval from 1.8 to 1.9 of DOM. When comparing both mammography system, the system screen-film has a lower variability in the distribution of objects associated to a DOM. (Author)

  14. Radiation field mapping in mammography units with TLDs

    Energy Technology Data Exchange (ETDEWEB)

    Castro, J.C.O.; Silva, J.O., E-mail: jonas.silva@ufg.br [Universidade Federal de Goiás (IFG), Goiânia (Brazil). Instituto de Física; Veneziani, G.R. [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo-SP (Brazil). Centro de Metrologia das Radiações

    2017-07-01

    Mammography is the most common imaging technique for breast cancer detection and its tracking. For dosimetry, is important to know the field intensity variation. In this work, TLD-100 were used to made a field mapping of a mammographic system from a hospital in Goiânia/GO. The maximum radiation intensity was 8 cm far from chest wall. The results obtained could be used in the optimization of the dosimetry in the equipment used in this work. (author)

  15. Role of a radiographer in mammography- new perspective

    International Nuclear Information System (INIS)

    Malik, S.

    2006-01-01

    giving the background to breast cancer in kenya. The importance of public education. The significance of early detection of breast cancer and patient survival. the emphasis of change of mind set of machine oriented radiographer to a clinically focused role. this involves a better understanding of the breast, the disease pattern, clinical examination of the breast and correlation with radiographic findings. The importance of other imaging modalities used to supplement mammography

  16. Supposed cancer risk from mammography. Reply to previous statements

    Energy Technology Data Exchange (ETDEWEB)

    Oeser, H; Koeppe, P; Rach, K [Freie Univ. Berlin (Germany, F.R.). Klinik fuer Radiologie, Nuklearmedizin und Physikalische Therapie

    1976-12-01

    The view that exposure to diagnostic radiation presents a cancer risk to the female breast should be considered together with the fact that the major factor is ageing of the patient. This risk factor is hidden in experimental and statistical studies on cancer production by exongenous agents; for instance, in studies of radiation effects, it is inherent in the time taken. The assumption that mammography presents a cancer risk is unjustifiable and is denied.

  17. Factors influencing elderly women's mammography screening decisions: implications for counseling

    OpenAIRE

    Schonberg, Mara A; McCarthy, Ellen P; York, Meghan; Davis, Roger B; Marcantonio, Edward R

    2007-01-01

    Abstract Background Although guidelines recommend that clinicians consider life expectancy before screening older women for breast cancer, many older women with limited life expectancies are screened. We aimed to identify factors important to mammography screening decisions among women aged 80 and older compared to women aged 65–79. Methods Telephone surveys of 107 women aged 80+ and 93 women aged 65–79 randomly selected from one academic primary care practice who were able to communicate in ...

  18. Evaluation of glandular dose in conventional and digital mammography systems

    International Nuclear Information System (INIS)

    Coutinho, Celia Maria Campos

    2009-01-01

    A survey was conducted to estimate the average glandular dose (D g ) for patients undergoing mammography and to report the distribution of incident air kerma (K i ), patient age, compressed breast thickness and glandular tissue content. From 1183 cranio caudal mammograms clinical data were collected and doses were measured. The survey data included mammograms from six mammography equipment: two screen/film units (SFM), two computed radiography units (CR) and two full-field digital (DR). Mean value for patient age and compressed breast thickness were 57 +-12 y and 5.4 +-1.4 cm, respectively. To investigate the importance of technical characteristics of three different mammography systems and breast glandularity, K i and D g were measured for individual breast of 392 patients from the original sample with compressed breast thickness in the range of 5.5 cm to 6.5 cm using tissue-equivalent phantoms of different glandularities manufactured in this study to mimic both the attenuation and the density of breast tissues. Mean K i value was 10.0 +-3.6 mGy for SFM systems, 12.0 +-3.6 mGy for CR systems and 4.9 +-1.3 mGy for DR systems. Mean D g value was 1.4 +-0.5 mGy for S/F systems, 1.7 +-0.5 mGy for CR systems and 0.9 +-0.2 mGy for D R systems. Statistical analysis for differences in mean values of K i and D g between mammography systems showed significant effect of their technical characteristics (p i and D g , it was observed statistically significant differences between the group of patients with 0 to 50% glandularity and the group of patients with 50 to 100% glandularity. (author)

  19. Investigation on calibration parameter of mammography calibration facilities at MINT

    International Nuclear Information System (INIS)

    Asmaliza Hashim; Wan Hazlinda Ismail; Md Saion Salikin; Muhammad Jamal Md Isa; Azuhar Ripin; Norriza Mohd Isa

    2004-01-01

    A mammography calibration facility has been established in the Medical Physics Laboratory, Malaysian Institute for Nuclear Technology Research (MINT). The calibration facility is established at the national level mainly to provide calibration services for radiation measuring test instruments or test tools used in quality assurance programme in mammography, which is being implemented in Malaysia. One of the accepted parameters that determine the quality of a radiation beam is the homogeneity coefficient. It is determined from the values of the 1 st and 2 nd Half Value Layer (HVL). In this paper, the consistency of the mammography machine beam qualities that is available in MINT, is investigated and presented. For calibration purposes, five radiation qualities namely 23, 25, 28, 30 and 35 kV, selectable from the control panel of the X-ray machine is used. Important parameters that are set for this calibration facility are exposure time, tube current, focal spot to detector distance (FDD) and beam size at specific distance. The values of homogeneity coefficient of this laboratory for the past few years tip to now be presented in this paper. Backscatter radiations are also considered in this investigation. (Author)

  20. Barriers to Mammography Screening: How to Overcome Them

    Directory of Open Access Journals (Sweden)

    Yasmin Hassoun

    2015-10-01

    Full Text Available Background: Screening mammography is an established intervention that leads to early breast cancer detection and reduced mortality. The Lebanese Ministry of Health has initiated yearly awareness campaigns and provided free mammography in multiple centers around the country. Methods: The study took place in two major areas of Lebanon - Beirut and South Lebanon. This cross-sectional survey aimed to assess knowledge about breast cancer screening and screening behaviors in the Lebanese population. The primary outcome of the study was to assess the reasons that prevented women from performing screening mammography based on our categories of questions: lack of knowledge about breast cancer, lack of access to screening facilities, failure of primary care physician to encourage screening behavior, and other reasons. Results: The major barriers to seek screening that had statistically significant P-values, in order of prevalence, included: lack of knowledge about breast cancer, followed by social reasons and lack of access. Conclusion: Given the prevalence of breast cancer in our population, it is important to understand the pitfalls that we experience in promoting awareness. Our study is the first study to reach out to the community to assess perceived barriers against screening and provide solutions for such barriers.

  1. Stereotaxic cytology of nonpalpable lesions detected at mammography

    International Nuclear Information System (INIS)

    Ciatto, S.; Rosselli del Turco, M.; Bravetti, P.; Catarzi, S.

    1991-01-01

    The authors report on 791 consecutive cases undergoing stereotaxic cytology for non palpable lesions detected at mammography. Histologic diagnosis (malignant = 179, benign = 107) or mammographic folow-up after at least one year (benign = 275) was available in 561 cases. The overall inadequacy rate of stereotaxic cytology was 0.21, and dependent on lesion type (benign = 0.25, malignant = 0.13 p<0.001) and on sampling operator experience (range 0.17-0.31, p<0.001). Sensitivity (dubious+positive, after exclusion of inadequates) was 0.83 and dependent on histologic type (infiltrating = 0.87, intraductal = 0.68). Specificity (negative/benign, after exclusion of inadequates) was 0.96. Stereotaxic cytology helped in reducing the number of unnecessary beningn biopsies and the biopsy ratio was 0.6 benign to 1 malignant biopsy. In cases with moderate suspicion at mammography the radiologist felt reassured by negative cytology and advised mammographic control rather than surgical biopsy. Cytology was determinant in advising surgical biopsy in 9 cancer cases whereas the absence of cytologic positivity contributed to diagnostic delay in 2 cancer cases. Overall, stereotaxic cytology allowed a relevant reduction of unnecessary benign biopsies and should be routinely employed in the diagnostic work-up of nonpalpable lesions detected at mammography

  2. An evaluation of musculoskeletal discomfort experience by radiographers performing mammography

    International Nuclear Information System (INIS)

    Gale, A.G.; May, J.

    1997-01-01

    The aim of this study was to establish whether breast screening radiographers experience any problems of musculoskeletal discomfort, and if so the nature and extent of these problems. The study was then further extended to investigate and determine possible occupational, causal or contributory factors, and to suggest recommendations to help alleviate any discomfort. To investigate this problem five main approaches were undertaken. These consisted of; a national survey, an observational study, the comparison of the physical measurements of the mammography units with anthropometric data, a detailed task analysis, and a body mapping study. The national survey set out to determine if the nature and frequency of such problems were higher in mammography than in other areas of radiography or in the general population. Additionally, comparisons were made with non-radiographic staff working at the same breast screening centres. Video recordings of radiographers performing breast screening were also made and posture analysis performed on these data. A detailed task analysis was conducted to identify interaction points and possible problems between the radiographer and the equipment which she is required to use. Physical measurements of the mammography units were made and compared with anthropometric measurements and guidelines. The body mapping study measured the build up of discomfort throughout the working day on several different mammography units. The results from the survey questionnaire indicated that some breast screening radiographers do experience musculoskeletal problems, and that these are different in nature and prevalence from the musculoskeletal discomfort reported by the two control groups. The prevalence of back pain reported by radiographers undertaking mammography was higher than that present in the normal population. No comparison could be made with other body areas as data regarding other types of musculoskeletal discomfort in the general population are

  3. An evaluation of musculoskeletal discomfort experience by radiographers performing mammography

    Energy Technology Data Exchange (ETDEWEB)

    Gale, A.G.; May, J

    1997-10-01

    The aim of this study was to establish whether breast screening radiographers experience any problems of musculoskeletal discomfort, and if so the nature and extent of these problems. The study was then further extended to investigate and determine possible occupational, causal or contributory factors, and to suggest recommendations to help alleviate any discomfort. To investigate this problem five main approaches were undertaken. These consisted of; a national survey, an observational study, the comparison of the physical measurements of the mammography units with anthropometric data, a detailed task analysis, and a body mapping study. The national survey set out to determine if the nature and frequency of such problems were higher in mammography than in other areas of radiography or in the general population. Additionally, comparisons were made with non-radiographic staff working at the same breast screening centres. Video recordings of radiographers performing breast screening were also made and posture analysis performed on these data. A detailed task analysis was conducted to identify interaction points and possible problems between the radiographer and the equipment which she is required to use. Physical measurements of the mammography units were made and compared with anthropometric measurements and guidelines. The body mapping study measured the build up of discomfort throughout the working day on several different mammography units. The results from the survey questionnaire indicated that some breast screening radiographers do experience musculoskeletal problems, and that these are different in nature and prevalence from the musculoskeletal discomfort reported by the two control groups. The prevalence of back pain reported by radiographers undertaking mammography was higher than that present in the normal population. No comparison could be made with other body areas as data regarding other types of musculoskeletal discomfort in the general population are

  4. Ultra-Fast Image Reconstruction of Tomosynthesis Mammography Using GPU

    Directory of Open Access Journals (Sweden)

    Arefan D

    2015-06-01

    Full Text Available Digital Breast Tomosynthesis (DBT is a technology that creates three dimensional (3D images of breast tissue. Tomosynthesis mammography detects lesions that are not detectable with other imaging systems. If image reconstruction time is in the order of seconds, we can use Tomosynthesis systems to perform Tomosynthesis-guided Interventional procedures. This research has been designed to study ultra-fast image reconstruction technique for Tomosynthesis Mammography systems using Graphics Processing Unit (GPU. At first, projections of Tomosynthesis mammography have been simulated. In order to produce Tomosynthesis projections, it has been designed a 3D breast phantom from empirical data. It is based on MRI data in its natural form. Then, projections have been created from 3D breast phantom. The image reconstruction algorithm based on FBP was programmed with C++ language in two methods using central processing unit (CPU card and the Graphics Processing Unit (GPU. It calculated the time of image reconstruction in two kinds of programming (using CPU and GPU.

  5. Development of Automatic Cluster Algorithm for Microcalcification in Digital Mammography

    International Nuclear Information System (INIS)

    Choi, Seok Yoon; Kim, Chang Soo

    2009-01-01

    Digital Mammography is an efficient imaging technique for the detection and diagnosis of breast pathological disorders. Six mammographic criteria such as number of cluster, number, size, extent and morphologic shape of microcalcification, and presence of mass, were reviewed and correlation with pathologic diagnosis were evaluated. It is very important to find breast cancer early when treatment can reduce deaths from breast cancer and breast incision. In screening breast cancer, mammography is typically used to view the internal organization. Clusterig microcalcifications on mammography represent an important feature of breast mass, especially that of intraductal carcinoma. Because microcalcification has high correlation with breast cancer, a cluster of a microcalcification can be very helpful for the clinical doctor to predict breast cancer. For this study, three steps of quantitative evaluation are proposed : DoG filter, adaptive thresholding, Expectation maximization. Through the proposed algorithm, each cluster in the distribution of microcalcification was able to measure the number calcification and length of cluster also can be used to automatically diagnose breast cancer as indicators of the primary diagnosis.

  6. Reader practice in mammography screen reporting in Australia

    International Nuclear Information System (INIS)

    Reed, W.; Poulos, A.; Brennan, P.

    2009-01-01

    Full text: Reader variability is a problem in mammography image reporting and compromises the efficacy of screening programmes. The purpose of this exploratory study was to survey reader practice in reporting screening mammograms in Australia to identify aspects of practice that warrant further investigation. Mammography reporting practice and influences on concentration and attention were investigated by using an original questionnaire distributed to screen readers in Australia. A response rate of 71% (83 out of 117) was achieved. Demographic data indicated that the majority of readers were over 46 years of age (73%), have been reporting on screening mammograms for over 10 years (61%), take less than 1 min to report upon a screening mammogram examination (66%), report up to 200 examinations in a single session (83%) and take up to 2 h to report one session (61%). A majority report on more than 5000 examinations annually (66%); 93% of participants regard their search strategy as systematic, 87% agreed that their concentration can vary throughout a session, 64% agreed that the relatively low number of positives can lead to lapses in concentration and attention and almost all (94%) participants agreed that methods to maximise concentration should be explored. Participants identified a range of influences on concentration within their working environment including volume of images reported in one session, image types and aspects of the physical environment. This study has provided important evidence of the need to investigate adverse influences on concentration during mammography screen reporting

  7. Performances of different digital mammography imaging systems: Evaluation and comparison

    Energy Technology Data Exchange (ETDEWEB)

    Bisogni, M.G. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy)]. E-mail: giuseppina.bisogni@pi.infn.it; Bulajic, D. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); International Centre for Theoretical Physics, Trieste (Italy); Delogu, P. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); Fantacci, M.E. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); Novelli, M. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); Quattrocchi, M. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); Rosso, V. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); Stefanini, A. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy)

    2005-07-01

    Digital mammography is entering routine clinical use and many commercial systems are now in use in the radiological units for screening and diagnostic mammography. At the same time, the research in the digital mammography field is very active in the development of more and more performing devices. In this paper we present the performance of single photon counting pixel detectors (MedipixI) tailored for digital mammographic applications. These devices are based on semiconductor (Si and GaAs) pixel detectors of different thickness, read-out by custom designed integrated circuits. To assess the imaging capability of such systems, the images of a mammographic phantom have been acquired in standard conditions for a clinical examination. The signal-to-noise ratio (SNR) of details simulating tumor masses has been evaluated. The same phantom has been also radiographed by three different commercial digital mammographic systems in the same reference conditions and a comparison in terms of SNR has been carried out. The spatial resolution of the single photon counting systems has also been evaluated by measuring the line spread function with the edge technique and then calculating the Modulation Transfer Function (MTF). The MTFs of the single photon counting systems have been compared with the MTFs of the commercial systems.

  8. Performances of different digital mammography imaging systems: Evaluation and comparison

    International Nuclear Information System (INIS)

    Bisogni, M.G.; Bulajic, D.; Delogu, P.; Fantacci, M.E.; Novelli, M.; Quattrocchi, M.; Rosso, V.; Stefanini, A.

    2005-01-01

    Digital mammography is entering routine clinical use and many commercial systems are now in use in the radiological units for screening and diagnostic mammography. At the same time, the research in the digital mammography field is very active in the development of more and more performing devices. In this paper we present the performance of single photon counting pixel detectors (MedipixI) tailored for digital mammographic applications. These devices are based on semiconductor (Si and GaAs) pixel detectors of different thickness, read-out by custom designed integrated circuits. To assess the imaging capability of such systems, the images of a mammographic phantom have been acquired in standard conditions for a clinical examination. The signal-to-noise ratio (SNR) of details simulating tumor masses has been evaluated. The same phantom has been also radiographed by three different commercial digital mammographic systems in the same reference conditions and a comparison in terms of SNR has been carried out. The spatial resolution of the single photon counting systems has also been evaluated by measuring the line spread function with the edge technique and then calculating the Modulation Transfer Function (MTF). The MTFs of the single photon counting systems have been compared with the MTFs of the commercial systems

  9. The influence of software filtering in digital mammography image quality

    Science.gov (United States)

    Michail, C.; Spyropoulou, V.; Kalyvas, N.; Valais, I.; Dimitropoulos, N.; Fountos, G.; Kandarakis, I.; Panayiotakis, G.

    2009-05-01

    Breast cancer is one of the most frequently diagnosed cancers among women. Several techniques have been developed to help in the early detection of breast cancer such as conventional and digital x-ray mammography, positron and single-photon emission mammography, etc. A key advantage in digital mammography is that images can be manipulated as simple computer image files. Thus non-dedicated commercially available image manipulation software can be employed to process and store the images. The image processing tools of the Photoshop (CS 2) software usually incorporate digital filters which may be used to reduce image noise, enhance contrast and increase spatial resolution. However, improving an image quality parameter may result in degradation of another. The aim of this work was to investigate the influence of three sharpening filters, named hereafter sharpen, sharpen more and sharpen edges on image resolution and noise. Image resolution was assessed by means of the Modulation Transfer Function (MTF).In conclusion it was found that the correct use of commercial non-dedicated software on digital mammograms may improve some aspects of image quality.

  10. The influence of software filtering in digital mammography image quality

    International Nuclear Information System (INIS)

    Michail, C; Spyropoulou, V; Valais, I; Panayiotakis, G; Kalyvas, N; Fountos, G; Kandarakis, I; Dimitropoulos, N

    2009-01-01

    Breast cancer is one of the most frequently diagnosed cancers among women. Several techniques have been developed to help in the early detection of breast cancer such as conventional and digital x-ray mammography, positron and single-photon emission mammography, etc. A key advantage in digital mammography is that images can be manipulated as simple computer image files. Thus non-dedicated commercially available image manipulation software can be employed to process and store the images. The image processing tools of the Photoshop (CS 2) software usually incorporate digital filters which may be used to reduce image noise, enhance contrast and increase spatial resolution. However, improving an image quality parameter may result in degradation of another. The aim of this work was to investigate the influence of three sharpening filters, named hereafter sharpen, sharpen more and sharpen edges on image resolution and noise. Image resolution was assessed by means of the Modulation Transfer Function (MTF).In conclusion it was found that the correct use of commercial non-dedicated software on digital mammograms may improve some aspects of image quality.

  11. Mammography image assessment; validity and reliability of current scheme

    International Nuclear Information System (INIS)

    Hill, C.; Robinson, L.

    2015-01-01

    Mammographers currently score their own images according to criteria set out by Regional Quality Assurance. The criteria used are based on the ‘Perfect, Good, Moderate, Inadequate’ (PGMI) marking criteria established by the National Health Service Breast Screening Programme (NHSBSP) in their Quality Assurance Guidelines of 2006 1 . This document discusses the validity and reliability of the current mammography image assessment scheme. Commencing with a critical review of the literature this document sets out to highlight problems with the national approach to the use of marking schemes. The findings suggest that ‘PGMI’ scheme is flawed in terms of reliability and validity and is not universally applied across the UK. There also appear to be differences in schemes used by trainees and qualified mammographers. Initial recommendations are to be made in collaboration with colleagues within the National Health Service Breast Screening Programme (NHSBSP), Higher Education Centres, College of Radiographers and the Royal College of Radiologists in order to identify a mammography image appraisal scheme that is fit for purpose. - Highlights: • Currently no robust evidence based marking tools in use for the assessment of images in mammography. • Is current system valid, reliable and robust? • How can the current image assessment tool be improved? • Should students and qualified mammographers use the same tool? • What marking criteria are available for image assessment?

  12. Computed tomographic mammography using a conventional body scanner.

    Science.gov (United States)

    Chang, C H; Nesbit, D E; Fisher, D R; Fritz, S L; Dwyer, S J; Templeton, A W; Lin, F; Jewell, W R

    1982-03-01

    The technique for computed tomographic (CT) examination of the breasts using a conventional body scanner is described, and experience with 67 patients is reported. In the diagnosis of both malignant and benign breast lesions, the results with a body scanner were equal to those of a dedicated CT/M mammographic unit. Although the CT study of the breast cannot replace conventional mammography in screening or in routine diagnostic workup, the unique capability of demonstrating both anatomic changes and increased iodide concentration in a cancer provides many advantages over conventional mammography. CT mammography appears to have the capability to detect breast cancers that are occult to other methods. Indications for a CT study of the breasts are: (1) clinically suspected breast cancer, especially with a mammographically occult lesion; (2) questionable mammographic findings, including microcalcifications, tumor shape, architectural distortion, and uncertain lesion location; and (3) evaluation of postbiopsy or postlumpectomy breast cancers when a primary irradiation therapy is contemplated. Breast CT also appears to be a valuable diagnostic tool in searching for a second primary breast cancer, follow-up study of postirradiation of breast cancer, followup study for postmastectomy patients, and screening procedure for genetically high-risk patients, especially those with dense breasts.

  13. Technical and dosimetric aspects of quality control in mammography

    International Nuclear Information System (INIS)

    Zoetelief, J.; Wit, N.J.P. de; Broerse, J.J.

    1989-01-01

    Before screening programmes using mammography are implemented, a cost benefit analysis has to be made and quality-control programme for the technical and dosimetric aspects adopted, including daily checks on film processing and total mammography procedure (radiography of a reference phantom, for which the average density, limiting value ± 0.20%, and focal charge is determined and which allows assessment of physical image quality) The installation of a MAs meter is essential for daily checks and can be used for determination of absorbed dose. Accurate determination of tube voltage (limiting value ±0.5 kV) is essential in regard to absorbed dose variations. Focal spot size should be measured rather than relying on the value specified by the manufacturer. The determination of the focal charge (mAs) value for actual radiographs of female breasts combined with a measurement of compressed breast thickness provides information on absorbed dose values for actual radiographs. An approximately 50 mm thick poly(methyl methacrylate) phantom can be used for determination of absorbed dose in mammography. (author)

  14. Energy functions for regularization algorithms

    Science.gov (United States)

    Delingette, H.; Hebert, M.; Ikeuchi, K.

    1991-01-01

    Regularization techniques are widely used for inverse problem solving in computer vision such as surface reconstruction, edge detection, or optical flow estimation. Energy functions used for regularization algorithms measure how smooth a curve or surface is, and to render acceptable solutions these energies must verify certain properties such as invariance with Euclidean transformations or invariance with parameterization. The notion of smoothness energy is extended here to the notion of a differential stabilizer, and it is shown that to void the systematic underestimation of undercurvature for planar curve fitting, it is necessary that circles be the curves of maximum smoothness. A set of stabilizers is proposed that meet this condition as well as invariance with rotation and parameterization.

  15. Physical model of dimensional regularization

    Energy Technology Data Exchange (ETDEWEB)

    Schonfeld, Jonathan F.

    2016-12-15

    We explicitly construct fractals of dimension 4-ε on which dimensional regularization approximates scalar-field-only quantum-field theory amplitudes. The construction does not require fractals to be Lorentz-invariant in any sense, and we argue that there probably is no Lorentz-invariant fractal of dimension greater than 2. We derive dimensional regularization's power-law screening first for fractals obtained by removing voids from 3-dimensional Euclidean space. The derivation applies techniques from elementary dielectric theory. Surprisingly, fractal geometry by itself does not guarantee the appropriate power-law behavior; boundary conditions at fractal voids also play an important role. We then extend the derivation to 4-dimensional Minkowski space. We comment on generalization to non-scalar fields, and speculate about implications for quantum gravity. (orig.)

  16. Maximum mutual information regularized classification

    KAUST Repository

    Wang, Jim Jing-Yan

    2014-09-07

    In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.

  17. Maximum mutual information regularized classification

    KAUST Repository

    Wang, Jim Jing-Yan; Wang, Yi; Zhao, Shiguang; Gao, Xin

    2014-01-01

    In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.

  18. Two-view versus single-view shear-wave elastography: comparison of observer performance in differentiating benign from malignant breast masses.

    Science.gov (United States)

    Lee, Su Hyun; Cho, Nariya; Chang, Jung Min; Koo, Hye Ryoung; Kim, Jin You; Kim, Won Hwa; Bae, Min Sun; Yi, Ann; Moon, Woo Kyung

    2014-02-01

    To determine whether two-view shear-wave elastography (SWE) improves the performance of radiologists in differentiating benign from malignant breast masses compared with single-view SWE. This prospective study was conducted with institutional review board approval, and written informed consent was obtained. B-mode ultrasonographic (US) and orthogonal SWE images were obtained for 219 breast masses (136 benign and 83 malignant; mean size, 14.8 mm) in 219 consecutive women (mean age, 47.9 years; range, 20-78 years). Five blinded radiologists independently assessed the likelihood of malignancy for three data sets: B-mode US alone, B-mode US and single-view SWE, and B-mode US and two-view SWE. Interobserver agreement regarding Breast Imaging Reporting and Data System (BI-RADS) category and the area under the receiver operating characteristic curve (AUC) of each data set were compared. Interobserver agreement was moderate (κ = 0.560 ± 0.015 [standard error of the mean]) for BI-RADS category assessment with B-mode US alone. When SWE was added to B-mode US, five readers showed substantial interobserver agreement (κ = 0.629 ± 0.017 for single-view SWE; κ = 0.651 ± 0.014 for two-view SWE). The mean AUC of B-mode US was 0.870 (range, 0.855-0.884). The AUC of B-mode US and two-view SWE (average, 0.928; range, 0.904-0.941) was higher than that of B-mode US and single-view SWE (average, 0.900; range, 0.890-0.920), with statistically significant differences for three readers (P ≤ .003). The performance of radiologists in differentiating benign from malignant breast masses was improved when B-mode US was combined with two-view SWE compared with that when B-mode US was combined with single-view SWE. © RSNA, 2013

  19. Regularized strings with extrinsic curvature

    International Nuclear Information System (INIS)

    Ambjoern, J.; Durhuus, B.

    1987-07-01

    We analyze models of discretized string theories, where the path integral over world sheet variables is regularized by summing over triangulated surfaces. The inclusion of curvature in the action is a necessity for the scaling of the string tension. We discuss the physical properties of models with extrinsic curvature terms in the action and show that the string tension vanishes at the critical point where the bare extrinsic curvature coupling tends to infinity. Similar results are derived for models with intrinsic curvature. (orig.)

  20. Circuit complexity of regular languages

    Czech Academy of Sciences Publication Activity Database

    Koucký, Michal

    2009-01-01

    Roč. 45, č. 4 (2009), s. 865-879 ISSN 1432-4350 R&D Projects: GA ČR GP201/07/P276; GA MŠk(CZ) 1M0545 Institutional research plan: CEZ:AV0Z10190503 Keywords : regular languages * circuit complexity * upper and lower bounds Subject RIV: BA - General Mathematics Impact factor: 0.726, year: 2009

  1. Preliminary results for positron emission mammography: real-time functional breast imaging in a conventional mammography gantry

    International Nuclear Information System (INIS)

    Weinberg, I.; Majewski, S.; Weisenberger, A.; Markowitz, A.; Aloj, L.; Majewski, L,; Danforth, D.; Mulshine, J.; Cowan, K.; Zujewski, J.; Chow, C.; Jones, E.; Chang, V.; Berg, W.; Frank, J.

    1996-01-01

    In order to optimally integrate radiotracer breast imaging within the breast clinic, anatomy and pathology should be easily correlated with functional nuclear medicine breast images. As a first step in the development of a hybrid functional/anatomic breast imaging platform with biopsy capability, a conventional X-ray mammography gantry was modified to image the compressed brest with positron emitters. Phantom studies with the positron emission mammography (PEM) device showed that a 1-cc hot spot could be detected within 5 min. A preliminary clinical trial demonstrated in vivo visualization of primary breast cancer within 4 min. For sites where positron-emitting radionuclides are available, PEM promises to achieve low-cost directed functional examination of breast abnormalities, with potential for achieving X-ray correlation and image-guided biopsy. (orig.)

  2. General inverse problems for regular variation

    DEFF Research Database (Denmark)

    Damek, Ewa; Mikosch, Thomas Valentin; Rosinski, Jan

    2014-01-01

    Regular variation of distributional tails is known to be preserved by various linear transformations of some random structures. An inverse problem for regular variation aims at understanding whether the regular variation of a transformed random object is caused by regular variation of components ...

  3. Ultrasound as an Adjunct to Mammography for Breast Cancer Screening: A Health Technology Assessment

    Science.gov (United States)

    Nikitovic-Jokic, Milica; Tu, Hong Anh; Palimaka, Stefan; Higgins, Caroline; Holubowich, Corinne

    2016-01-01

    Background Screening with mammography can detect breast cancer early, before clinical symptoms appear. Some cancers, however, are not captured with mammography screening alone. Ultrasound has been suggested as a safe adjunct screening tool that can detect breast cancers missed on mammography. We investigated the benefits, harms, cost-effectiveness, and cost burden of ultrasound as an adjunct to mammography compared with mammography alone for screening women at average risk and at high risk for breast cancer. Methods We searched Ovid MEDLINE, Ovid Embase, EBM Reviews, and the NHS Economic Evaluation Database, from January 1998 to June 2015, for evidence of effectiveness, harms, diagnostic accuracy, and cost-effectiveness. Only studies evaluating the use of ultrasound as an adjunct to mammography in the specified populations were included. We also conducted a cost analysis to estimate the costs in Ontario over the next 5 years to fund ultrasound as an adjunct to mammography in breast cancer screening for high-risk women who are contraindicated for MRI, the current standard of care to supplement mammography. Results No studies in average-risk women met the inclusion criteria of the clinical review. We included 5 prospective, paired cohort studies in high-risk women, 4 of which were relevant to the Ontario context. Adjunct ultrasound identified between 2.3 and 5.9 additional breast cancers per 1,000 screens. The average pooled sensitivity of mammography and ultrasound was 53%, a statistically significant increase relative to mammography alone (absolute increase 13%; P screening alone. The GRADE for this body of evidence was low. Additional annual costs of using breast ultrasound as an adjunct to mammography for high-risk women in Ontario contraindicated for MRI would range from $15,500 to $30,250 in the next 5 years. Conclusions We found no evidence that evaluated the comparative effectiveness or diagnostic accuracy of screening breast ultrasound as an adjunct to

  4. Mammography: an update of the EUSOBI recommendations on information for women.

    Science.gov (United States)

    Sardanelli, Francesco; Fallenberg, Eva M; Clauser, Paola; Trimboli, Rubina M; Camps-Herrero, Julia; Helbich, Thomas H; Forrai, Gabor

    2017-02-01

    This article summarises the information to be offered to women about mammography. After a delineation of the aim of early diagnosis of breast cancer, the difference between screening mammography and diagnostic mammography is explained. The need to bring images and reports from the previous mammogram (and from other recent breast imaging examinations) is highlighted. Mammography technique and procedure are described with particular attention to discomfort and pain experienced by a small number of women who undergo the test. Information is given on the recall during a screening programme and on the request for further work-up after a diagnostic mammography. The logic of the mammography report and of classification systems such as R1-R5 and BI-RADS is illustrated, and brief but clear information is given about the diagnostic performance of the test, with particular reference to interval cancers, i.e., those cancers that are missed at screening mammography. Moreover, the breast cancer risk due to radiation exposure from mammography is compared to the reduction in mortality obtained with the test, and the concept of overdiagnosis is presented with a reliable estimation of its extent. Information about new mammographic technologies (tomosynthesis and contrast-enhanced spectral mammography) is also given. Finally, frequently asked questions are answered. • Direct digital mammography should be preferred to film-screen or phosphor plates. • Screening (in asymptomatic women) should be distinguished from diagnosis (in symptomatic women). • A breast symptom has to be considered even after a negative mammogram. • Digital breast tomosynthesis increases cancer detection and decreases the recall rate. • Contrast-enhanced spectral mammography can help in cancer detection and lesion characterisation.

  5. Our trial to improve patient positioning during mammography

    International Nuclear Information System (INIS)

    Nakayama, Takashi; Kotsuma, Yoshikazu; Hiramatsu, Sawako

    2007-01-01

    For effective breast cancer screening, reading of high-quality mammograms is essential, and for this purpose proper patient positioning during mammography is important. At our Shin-Osaka Mammography Seminar, which includes eight institutions, a physician and nine radiology technicians get together weekly in order to critically review mammogram reading and techniques for obtaining good mammograms. We have recognized that patient positioning has a great effect on mammogram quality, particularly for women in their 40 s who have dense mammary glands, and we have adopted a digital mammography system, or comparative mammography for such patients. Since July 2005, we have critically reviewed positioning every 3 or 4 months with the aim of improving our technique. Eight institutions have participated in this trial, each contributing mammograms taken recently from 20 to 30 consecutive participants, and the grade of positioning has been determined according to the Institutional Mammogram Estimation Standard (6 items, each scoring a maximum of 4 points, total 24 points) proposed by the Central Committee for Quality Control of Mammography Screening. The estimation has been done by both ourselves and committee members. When a total of 20 points or more is obtained and all 6 items score 3 points or more, it is considered that the positioning has been good, and this is termed ''Positioning A'' (P-A). On the other hand, if the total score is less than 20 points, and any one of the 6 items scores less than 3 points, it is considered that positioning has been inadequate, and this is termed ''Positioning-D'' (P-D). At the first review meeting, which was held before our critical study, P-A accounted for 48% of cases, and this had improved to 72% at the second meeting, and to 66% at the third. P-D accounted for 41% of cases at the first meeting, 20% at the second, and 21% at the third. Thus our trial involving discussion between a physician and technicians to critically review good

  6. Local recurrences after conservative surgery and irradiation for breast cancer: Diagnosis with mammography and ultrasound. Mammographie und Sonographie in der Rezidivdiagnostik nach brusterhaltender Therapie des Mammakarzinoms

    Energy Technology Data Exchange (ETDEWEB)

    Buchberger, W; Hamberger, L; Schoen, G [Innsbruck Univ. (Austria). Universitaetsklinik fuer Radiodiagnostik; Steixner, G; Fritsch, E [Innsbruck Univ. (Austria). Universitaetsklinik fuer Strahlentherapie

    1991-06-01

    89 patients, who underwent conservative surgery for breast cancer were followed up with mammography and real-time sonography. 78 patients underwent postoperative irradiation. Depending on the time interval between irradiation and examination various alterations in mammographic and sonographic patterns were evident. Of 14 biospy-confirmed local recurrences, 11 were diagnosed by mammography and 12 by sonography. Combined use of mammography and sonography should therefore lead to better results in the diagnosis of local recurrences and to a reduction of unnecessary biopsies. (orig./GDG).

  7. ACR BI-RADS Assessment Category 4 Subdivisions in Diagnostic Mammography: Utilization and Outcomes in the National Mammography Database.

    Science.gov (United States)

    Elezaby, Mai; Li, Geng; Bhargavan-Chatfield, Mythreyi; Burnside, Elizabeth S; DeMartini, Wendy B

    2018-05-01

    Purpose To determine the utilization and positive predictive value (PPV) of the American College of Radiology (ACR) Breast Imaging Data and Reporting System (BI-RADS) category 4 subdivisions in diagnostic mammography in the National Mammography Database (NMD). Materials and Methods This study involved retrospective review of diagnostic mammography data submitted to the NMD from January 1, 2008 to December 30, 2014. Utilization rates of BI-RADS category 4 subdivisions were compared by year, facility (type, location, census region), and examination (indication, finding type) characteristics. PPV3 (positive predictive value for biopsies performed) was calculated overall and according to category 4 subdivision. The χ 2 test was used to test for significant associations. Results Of 1 309 950 diagnostic mammograms, 125 447 (9.6%) were category 4, of which 33.3% (41 841 of 125 447) were subdivided. Subdivision utilization rates were higher (P use, subdivisions were utilized in the minority (33.3% [41 841 of 125 447]) of category 4 diagnostic mammograms, with variability based on facility and examination characteristics. When subdivisions were used, PPV3s were in BI-RADS-specified malignancy ranges. This analysis supports the use of subdivisions in broad practice and, given benefits for patient care, should motivate increased utilization. © RSNA, 2018 Online supplemental material is available for this article.

  8. Solid-state dosimeters: A new approach for mammography measurements

    International Nuclear Information System (INIS)

    Brateman, Libby F.; Heintz, Philip H.

    2015-01-01

    Purpose: To compare responses of modern commercially available solid-state dosimeters (SStDs) used in mammography medical physics surveys for two major vendors of current digital mammography units. To compare differences in dose estimates among SStD responses with ionization chamber (IC) measurements for several target/filter (TF) combinations and report their characteristics. To review scientific bases for measurements of quantities required for mammography for traditional measurement procedures and SStDs. Methods: SStDs designed for use with modern digital mammography units were acquired for evaluation from four manufacturers. Each instrument was evaluated under similar conditions with the available mammography beams provided by two modern full-field digital mammography units in clinical use: a GE Healthcare Senographe Essential (Essential) and a Hologic Selenia Dimensions 5000 (Dimensions), with TFs of Mo/Mo, Mo/Rh; and Rh/Rh and W/Rh, W/Ag, and W/Al, respectively. Measurements were compared among the instruments for the TFs over their respective clinical ranges of peak tube potentials for kVp and half-value layer (HVL) measurements. Comparisons for air kerma (AK) and their associated relative calculated average glandular doses (AGDs), i.e., using fixed mAs, were evaluated over the limited range of 28–30 kVp. Measurements were compared with reference IC measurements for AK, reference HVLs and calculated AGD, for two compression paddle heights for AK, to evaluate scatter effects from compression paddles. SStDs may require different positioning from current mammography measurement protocols. Results: Measurements of kVp were accurate in general for the SStDs (within −1.2 and +1.1 kVp) for all instruments over a wide range of set kVp’s and TFs and most accurate for Mo/Mo and W/Rh. Discrepancies between measurements and reference values were greater for HVL and AK. Measured HVL values differed from reference values by −6.5% to +3.5% depending on the SStD and

  9. Magnification mammography: a comparison of full-field digital mammography and screen-film mammography for the detection of simulated small masses and microcalcifications

    International Nuclear Information System (INIS)

    Hermann, K.P.; Obenauer, S.; Funke, M.; Grabbe, E.H.

    2002-01-01

    The objective of this study was a comparison of a full-field digital mammography (FFDM) system and a conventional screen-film mammography (SFM) system with respect to the detectability of simulated small masses and microcalcifications in the magnification mode. All images were obtained using 1.8 times magnification. The FFDM images were obtained at radiation dose levels of 1.39, 1.0, 0.7, 0.49 and 0.24 times that of the SFM images. A contrast-detail phantom was used to compare the detection of simulated lesions using a four alternative forced-choice reader study with three readers. The correct observation ratio (COR) was calculated as the fraction of correctly identified lesions to the total number of simulated lesions. Soft-copy reading was performed for all digital images. Direct magnification images acquired with the digital system showed a lower object contrast threshold than those acquired with the conventional system. For equal radiation dose, the digital system provided a significantly increased COR (0.95) compared with the screen-film system (0.82). For simulated microcalcifications, the corresponding difference was 0.90 to 0.72. The digital system allowed equal detection to screen-film at 40% of the radiation dose used for screen film. Digital magnification images are superior to screen-film magnification images for the detection of simulated small masses and microcalcifications even at a lower radiation dose. (orig.)

  10. Prospective study aiming to compare 2D mammography and tomosynthesis + synthesized mammography in terms of cancer detection and recall. From double reading of 2D mammography to single reading of tomosynthesis.

    Science.gov (United States)

    Romero Martín, Sara; Raya Povedano, Jose Luis; Cara García, María; Santos Romero, Ana Luz; Pedrosa Garriguet, Margarita; Álvarez Benito, Marina

    2018-06-01

    To evaluate tomosynthesis compared with 2D-mammography in cancer detection and recalls in a screening-programme, and assess performing synthesized instead of 2D, and compare double reading of 2D with single reading of tomosynthesis. Women (age 50-69 years) participating in the screening-programme were included. 2D-mammography and tomosynthesis were performed. There were four reading models: 2D-mammography (first); 2D-mammography (second); tomosynthesis + synthesized (third); tomosynthesis + synthesized + 2D (fourth reading). Paired double reading of 2D (first+second) and tomosynthesis (third+fourth) were analysed. In 16,067 participants, there were 98 cancers and 1,196 recalls. Comparing double reading of 2D with single reading of tomosynthesis, there was an increase of 12.6 % in cancer detection with the third reading (p= 0.043) and 6.9 % with the fourth reading (p=0.210), and a decrease in recalls of 40.5 % (ptomosynthesis. Single reading of tomosynthesis plus synthesized increased cancer detection and decreased recalls compared with double reading 2D. 2D did not improve results when added to tomosynthesis. • Tomosynthesis increases cancer detection and decreases recall rates versus 2D mammography. • Synthesized-mammography avoids performing 2D, showing higher cancer detection. • Single reading of tomosynthesis + synthesized is feasible as a new practice.

  11. Mammography in Norway: Image quality and total performance; Mammografivirksomhet i Norge: Bildekvalitet og totalytelse

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, J.B.; Skretting, A. [Norske Radiumhospital, Oslo (Norway); Widmark, A. [Statens Straalevern, Oesteraas (Norway)

    1997-04-01

    This report describes a method for assessing the total performance in mammography based on Receiver Operating Characteristic (ROC) analysis. In the time period from December 1993 to March 1994 the method was applied to assess the total performance of all the 45 Norwegian mammography laboratories operative at that time. Image quality characteristics in each laboratory was established by use of well-known phantoms.

  12. Contrast-enhanced spectral mammography in patients referred from the breast cancer screening programme

    Energy Technology Data Exchange (ETDEWEB)

    Lobbes, Marc B.I.; Wildberger, Joachim E. [Maastricht University Medical Center, Department of Radiology, Maastricht (Netherlands); GROW School for Oncology and Developmental Biology, Maastricht (Netherlands); Lalji, Ulrich; Houwers, Janneke; Nijssen, Estelle C. [Maastricht University Medical Center, Department of Radiology, Maastricht (Netherlands); Nelemans, Patty J. [Maastricht University, Department of Epidemiology, Maastricht (Netherlands); Roozendaal, Lori van; Heuts, Esther [Maastricht University Medical Center, Department of Surgical Oncology, Maastricht (Netherlands); Smidt, Marjolein L. [Maastricht University Medical Center, Department of Surgical Oncology, Maastricht (Netherlands); GROW School for Oncology and Developmental Biology, Maastricht (Netherlands)

    2014-07-15

    Feasibility studies have shown that contrast-enhanced spectral mammography (CESM) increases diagnostic accuracy of mammography. We studied diagnostic accuracy of CESM in patients referred from the breast cancer screening programme, who have a lower disease prevalence than previously published papers on CESM. During 6 months, all women referred to our hospital were eligible for CESM. Two radiologists blinded to the final diagnosis provided BI-RADS classifications for conventional mammography and CESM. Statistical significance of differences between mammography and CESM was calculated using McNemar's test. Receiver operating characteristic (ROC) curves were constructed for both imaging modalities. Of the 116 eligible women, 113 underwent CESM. CESM increased sensitivity to 100.0 % (+3.1 %), specificity to 87.7 % (+45.7 %), PPV to 76.2 % (+36.5 %) and NPV to 100.0 % (+2.9 %) as compared to mammography. Differences between conventional mammography and CESM were statistically significant (p < 0.0001). A similar trend was observed in the ROC curve. For conventional mammography, AUC was 0.779. With CESM, AUC increased to 0.976 (p < 0.0001). In addition, good agreement between tumour diameters measured using CESM, breast MRI and histopathology was observed. CESM increases diagnostic performance of conventional mammography, even in lower prevalence patient populations such as referrals from breast cancer screening. (orig.)

  13. Automated daily quality control analysis for mammography in a multi-unit imaging center.

    Science.gov (United States)

    Sundell, Veli-Matti; Mäkelä, Teemu; Meaney, Alexander; Kaasalainen, Touko; Savolainen, Sauli

    2018-01-01

    Background The high requirements for mammography image quality necessitate a systematic quality assurance process. Digital imaging allows automation of the image quality analysis, which can potentially improve repeatability and objectivity compared to a visual evaluation made by the users. Purpose To develop an automatic image quality analysis software for daily mammography quality control in a multi-unit imaging center. Material and Methods An automated image quality analysis software using the discrete wavelet transform and multiresolution analysis was developed for the American College of Radiology accreditation phantom. The software was validated by analyzing 60 randomly selected phantom images from six mammography systems and 20 phantom images with different dose levels from one mammography system. The results were compared to a visual analysis made by four reviewers. Additionally, long-term image quality trends of a full-field digital mammography system and a computed radiography mammography system were investigated. Results The automated software produced feature detection levels comparable to visual analysis. The agreement was good in the case of fibers, while the software detected somewhat more microcalcifications and characteristic masses. Long-term follow-up via a quality assurance web portal demonstrated the feasibility of using the software for monitoring the performance of mammography systems in a multi-unit imaging center. Conclusion Automated image quality analysis enables monitoring the performance of digital mammography systems in an efficient, centralized manner.

  14. Contrast-enhanced spectral mammography in patients referred from the breast cancer screening programme

    International Nuclear Information System (INIS)

    Lobbes, Marc B.I.; Wildberger, Joachim E.; Lalji, Ulrich; Houwers, Janneke; Nijssen, Estelle C.; Nelemans, Patty J.; Roozendaal, Lori van; Heuts, Esther; Smidt, Marjolein L.

    2014-01-01

    Feasibility studies have shown that contrast-enhanced spectral mammography (CESM) increases diagnostic accuracy of mammography. We studied diagnostic accuracy of CESM in patients referred from the breast cancer screening programme, who have a lower disease prevalence than previously published papers on CESM. During 6 months, all women referred to our hospital were eligible for CESM. Two radiologists blinded to the final diagnosis provided BI-RADS classifications for conventional mammography and CESM. Statistical significance of differences between mammography and CESM was calculated using McNemar's test. Receiver operating characteristic (ROC) curves were constructed for both imaging modalities. Of the 116 eligible women, 113 underwent CESM. CESM increased sensitivity to 100.0 % (+3.1 %), specificity to 87.7 % (+45.7 %), PPV to 76.2 % (+36.5 %) and NPV to 100.0 % (+2.9 %) as compared to mammography. Differences between conventional mammography and CESM were statistically significant (p < 0.0001). A similar trend was observed in the ROC curve. For conventional mammography, AUC was 0.779. With CESM, AUC increased to 0.976 (p < 0.0001). In addition, good agreement between tumour diameters measured using CESM, breast MRI and histopathology was observed. CESM increases diagnostic performance of conventional mammography, even in lower prevalence patient populations such as referrals from breast cancer screening. (orig.)

  15. Compliance with European Guidelines for Diagnostic Mammography in a Decentralized Health-Care Setting

    International Nuclear Information System (INIS)

    Jensen, A.; Mikkelsen, G.J.; Vestergaard, M.; Lynge, E.; Vejborg, I.

    2005-01-01

    Purpose: To evaluate the compliance of Danish mammography clinics with requirements concerning organization, activity volume, and assessment procedures from two European guidelines for quality assurance in diagnostic mammography (EUSOMA and EUREF). Material and Methods: We used individual records on all diagnostic mammographies performed in Denmark in 2000, and questionnaires given to Danish mammography clinics in 2000, 2002, and 2004. Results: The study showed a marked centralization of the diagnostic activity from 2000 to 2004 to a smaller number of public breast assessment centers with full multidisciplinary breast assessment. However, a relatively large number of these centers did not comply with the activity volume requirement of 2000 mammograms per clinic per year. The number of private diagnostic mammography clinics performing basic diagnostic mammography has remained fairly stable in the period 2000 to 2004. Compared with public breast assessment centers, the private diagnostic mammography clinics had a lower compliance with activity volume requirements. Conclusion: A marked proportion of Danish public breast assessment centers operate with less than optimal activity volume, suggesting that further centralization would be appropriate. The situation in private diagnostic mammography clinics may cause concern, as our study showed that the majority of these clinics did not meet the activity volume requirements

  16. Regularized Statistical Analysis of Anatomy

    DEFF Research Database (Denmark)

    Sjöstrand, Karl

    2007-01-01

    This thesis presents the application and development of regularized methods for the statistical analysis of anatomical structures. Focus is on structure-function relationships in the human brain, such as the connection between early onset of Alzheimer’s disease and shape changes of the corpus...... and mind. Statistics represents a quintessential part of such investigations as they are preluded by a clinical hypothesis that must be verified based on observed data. The massive amounts of image data produced in each examination pose an important and interesting statistical challenge...... efficient algorithms which make the analysis of large data sets feasible, and gives examples of applications....

  17. Regularization methods in Banach spaces

    CERN Document Server

    Schuster, Thomas; Hofmann, Bernd; Kazimierski, Kamil S

    2012-01-01

    Regularization methods aimed at finding stable approximate solutions are a necessary tool to tackle inverse and ill-posed problems. Usually the mathematical model of an inverse problem consists of an operator equation of the first kind and often the associated forward operator acts between Hilbert spaces. However, for numerous problems the reasons for using a Hilbert space setting seem to be based rather on conventions than on an approprimate and realistic model choice, so often a Banach space setting would be closer to reality. Furthermore, sparsity constraints using general Lp-norms or the B

  18. Academic Training Lecture - Regular Programme

    CERN Multimedia

    PH Department

    2011-01-01

    Regular Lecture Programme 9 May 2011 ACT Lectures on Detectors - Inner Tracking Detectors by Pippa Wells (CERN) 10 May 2011 ACT Lectures on Detectors - Calorimeters (2/5) by Philippe Bloch (CERN) 11 May 2011 ACT Lectures on Detectors - Muon systems (3/5) by Kerstin Hoepfner (RWTH Aachen) 12 May 2011 ACT Lectures on Detectors - Particle Identification and Forward Detectors by Peter Krizan (University of Ljubljana and J. Stefan Institute, Ljubljana, Slovenia) 13 May 2011 ACT Lectures on Detectors - Trigger and Data Acquisition (5/5) by Dr. Brian Petersen (CERN) from 11:00 to 12:00 at CERN ( Bldg. 222-R-001 - Filtration Plant )

  19. Added value of one-view breast tomosynthesis combined with digital mammography according to reader experience

    International Nuclear Information System (INIS)

    Thomassin-Naggara, Isabelle; Perrot, Nicolas; Dechoux, Sophie; Ribeiro, Carine; Chopier, Jocelyne; Bazelaire, Cedric de

    2015-01-01

    Highlights: • Breast tomosynthesis improves diagnostic performance especially for radiologists with lower experience in mammography. • Adding only one-view digital breast tomosynthesis to mammography improves the cancer detection rate. • Breast tomosynthesis is mainly useful for helping radiologists to detect architectural distortion. - Abstract: Purpose: To retrospectively evaluate the added value of one-view breast tomosynthesis in adjunct with mammography to characterize breast lesions. Materials and methods: Our institutional ethics committees approved the study and granted a waiver of informed consent. One hundred fifty-five women (mean age, 51.3 years, range: 24–92 years) who systematically underwent mammography and breast tomosynthesis with subsequent percutaneous biopsy were analyzed. Four radiologists (two seniors, R1 and R2, and two juniors, R3 and R4 with 30, 10, 3 and 1 years of experience in breast imaging, respectively) independently reviewed exams in two steps: mammography alone and tomosynthesis in adjunct with mammography. The lesions in the cohort included 39.3% (61/155) cancers, 2.5% (4/155) high-risk lesions and 58.1% (90/155) benign lesions. A receiver operating characteristic (ROC) curve analysis was performed to compare the results of the two readings. Results: There was almost perfect agreement irrespective of reader experience for the reading of the mammography in adjunct with tomosynthesis, whereas agreement was poor between junior and senior readers for the reading of mammography alone. Area under the ROC (Az) values for the tomosynthesis in adjunct with mammography were significantly better than Az values for mammography alone for all readers except the most experienced, for whom only a tendency was noted. The proportion of cancers undiagnosed by mammography alone that were well diagnosed by tomosynthesis in adjunct with mammography was 6.5% (4/61), 13.1% (8/61), 27.8% (17/61) and 26.2% (16/61) for Readers 1, 2, 3 and 4

  20. Added value of one-view breast tomosynthesis combined with digital mammography according to reader experience

    Energy Technology Data Exchange (ETDEWEB)

    Thomassin-Naggara, Isabelle, E-mail: isabelle.thomassin@tnn.aphp.fr [Sorbonne Universités, UPMC Univ Paris 06, IUC, 75005 Paris (France); INSERM, UMR970, Equipe 2, Imagerie de l’angiogenèse, 75005 Paris (France); AP-HP, Hôpital Tenon, Department of Radiology, 4 rue de la Chine, 75020 Paris (France); Perrot, Nicolas [AP-HP, Hôpital Tenon, Department of Radiology, 4 rue de la Chine, 75020 Paris (France); Centre Pyramides, Paris (France); Dechoux, Sophie [Sorbonne Universités, UPMC Univ Paris 06, IUC, 75005 Paris (France); AP-HP, Hôpital Tenon, Department of Radiology, 4 rue de la Chine, 75020 Paris (France); Ribeiro, Carine [Centre Pyramides, Paris (France); Chopier, Jocelyne [AP-HP, Hôpital Tenon, Department of Radiology, 4 rue de la Chine, 75020 Paris (France); Bazelaire, Cedric de [APHP, Department of Radiology, Hôpital Saint Louis, 75010 Paris (France)

    2015-02-15

    Highlights: • Breast tomosynthesis improves diagnostic performance especially for radiologists with lower experience in mammography. • Adding only one-view digital breast tomosynthesis to mammography improves the cancer detection rate. • Breast tomosynthesis is mainly useful for helping radiologists to detect architectural distortion. - Abstract: Purpose: To retrospectively evaluate the added value of one-view breast tomosynthesis in adjunct with mammography to characterize breast lesions. Materials and methods: Our institutional ethics committees approved the study and granted a waiver of informed consent. One hundred fifty-five women (mean age, 51.3 years, range: 24–92 years) who systematically underwent mammography and breast tomosynthesis with subsequent percutaneous biopsy were analyzed. Four radiologists (two seniors, R1 and R2, and two juniors, R3 and R4 with 30, 10, 3 and 1 years of experience in breast imaging, respectively) independently reviewed exams in two steps: mammography alone and tomosynthesis in adjunct with mammography. The lesions in the cohort included 39.3% (61/155) cancers, 2.5% (4/155) high-risk lesions and 58.1% (90/155) benign lesions. A receiver operating characteristic (ROC) curve analysis was performed to compare the results of the two readings. Results: There was almost perfect agreement irrespective of reader experience for the reading of the mammography in adjunct with tomosynthesis, whereas agreement was poor between junior and senior readers for the reading of mammography alone. Area under the ROC (Az) values for the tomosynthesis in adjunct with mammography were significantly better than Az values for mammography alone for all readers except the most experienced, for whom only a tendency was noted. The proportion of cancers undiagnosed by mammography alone that were well diagnosed by tomosynthesis in adjunct with mammography was 6.5% (4/61), 13.1% (8/61), 27.8% (17/61) and 26.2% (16/61) for Readers 1, 2, 3 and 4

  1. Image quality in conventional film screen system, digital phosphor storage plate mammography in magnification technique and digital mammography in CCD-technique

    International Nuclear Information System (INIS)

    Schulz-Wendtland, R.; Aichinger, U.; Boehner, C.; Dobritz, M.; Bautz, W.; Saebel, M.

    2000-01-01

    Purpose: Comparison of image quality between conventional film screen system, digital phosphor storage plate mammography in magnification technique and digital mammography in CCD-technique. Materials and Methods: Radiograms of a RMI-mammography phantom were acquired using a conventional film screen system, two digital storage plate systems and two digital systems in CCD-technique. Additionally, the radiograms of one digital phosphor storage plate system were post-processed emphasizing contrast and included in the comparison. Results: The detectability of details was the best with the digital mammography in CCD-technique in comparison with the conventional film screen technique resp. digital phosphor storage plate in magnification technique. Conclusions: Based on these results there is the possibility to replace the conventional film screen system by further studies - this has to be confirmed. (orig.) [de

  2. Descriptive study of the quality control in mammography; Estudio descriptivo del control de calidad en mamografia

    Energy Technology Data Exchange (ETDEWEB)

    Gaona, E.; Perdigon C, G.M.; Casian C, G.A.; Azorin N, J.; Diaz G, J.A.I.; Arreola, M. [UAM, Xochimilco 14000 Mexico D.F. (Mexico)

    2005-07-01

    The goal of mammography is to provide contrast between a lesion that is possible residing within the breast and normal surrounding tissue. Quality control is essential for maintaining the contrast imaging performance of a mammography system and incorporate tests that are relevant in that they are predictive of future degradation of contrast imaging performance. These tests will also be done at frequency that is high enough to intercept most drifts in quality imaging or performance before they become diagnostically significant. The quality control study has as objective to describe the results of the assessment of quality imaging elements (film optical density, contrast (density difference), uniformity, resolution and noise) of 62 mammography departments without quality control program and comparison these results with a mammography reference department with a quality control program. When comparing the results they allow seeing the clinical utility of to have a quality control program to reduce the errors of mammography interpretation. (Author)

  3. Use of Iodine-based contrast media in digital full-field mammography - initial experience

    International Nuclear Information System (INIS)

    Diekmann, F.; Diekmann, S.; Taupitz, M.; Bick, U.; Winzer, K.-J.; Huettner, C.; Muller, S.; Jeunehomme, F.; Hamm, B.

    2003-01-01

    Aim: To investigate the use of iodine-based contrast media in digital full-field mammography. Methods: After performing initial phantom studies, seven patients underwent digital mammography (Senographe 2000D, GE Medical Systems, Milwaukee, USA) using a specially filtered beam before as well as 60, 120, and 180 seconds after injection of 80 ml of iodine contrast medium (Ultravist 370, Schering AG, Germany). The precontrast mammograms were then subtracted from the postcontrast mammograms and the resulting images compared with a contrast-enhanced dynamic MRI study, performed on all women. Results: Contrast medium accumulation within the tumors was visualized with a good quality in all cases. The conditions under which successful contrast-enhanced digital mammography can be performed were determined in phantom studies. Conclusions: Contrast-enhanced digital mammography has a potential for improving the visualization of breast tumors in mammography using special beam filtering, adjusted X-ray parameters, proper timing, and suitable subtraction software. (orig.) [de

  4. Exposure and roentgen-area-product in xeromammography and conventional mammography

    Energy Technology Data Exchange (ETDEWEB)

    Baxt, J H; Bushong, S C; Glaze, S; Kothari, S [Baylor Univ., Houston, Tex. (USA). Coll. of Medicine

    1976-01-01

    X-ray mammography is assuming increasing importance in the early detection of breast cancer. The principal disadvantage to conventional mammography is high patient dose. Xeromammography offers three advantages over conventional mammography: (a) lower patient dose, (b) better image quality and (c) no special mammography tube required. A transmission ionization chamber and thermoluminescent dosimeters were used to measure the roentgen-area-product and the exposure for three view examination. Average roentgen-area-product values of 6500 and 4200 R-cm/sup 2/ were observed for conventional mammography and xeromammography respectively. The medial surface of the breast received the highest radiation exposure for both types of examinations and this was shown to be 11.5 and 5.1 R respectively. Omission of the axillary view from the examination reduces the patient dose in both types by approximately 60 %.

  5. Situational quality evaluation of mammography services at state of Minas Gerais, Brazil

    International Nuclear Information System (INIS)

    Joana, Georgia S.; Oliveira, Mauricio de; Andrade, Mauricio C. de; Cesar, Adriana C.Z.; Peixoto, Joao E.

    2011-01-01

    Breast cancer is the leading cause of cancer deaths in women. Currently, the most effective method for early detection of this cancer is the mammography, and to achieve the standard definition and contrast, the whole system of imaging must operate under optimal conditions. This paper presents the results of the assessment of mammography centers in the state of Minas Gerais, which was held with the aim of supporting the actions of the State Program of Quality Control in Mammography. These results indicated that less than half of mammography achieved the minimum standard of image quality, endorsing the need of a monitoring more efficient and effective, which led to the establishment, in Minas Gerais, of the monthly monitoring of image quality in mammography. (author)

  6. RES: Regularized Stochastic BFGS Algorithm

    Science.gov (United States)

    Mokhtari, Aryan; Ribeiro, Alejandro

    2014-12-01

    RES, a regularized stochastic version of the Broyden-Fletcher-Goldfarb-Shanno (BFGS) quasi-Newton method is proposed to solve convex optimization problems with stochastic objectives. The use of stochastic gradient descent algorithms is widespread, but the number of iterations required to approximate optimal arguments can be prohibitive in high dimensional problems. Application of second order methods, on the other hand, is impracticable because computation of objective function Hessian inverses incurs excessive computational cost. BFGS modifies gradient descent by introducing a Hessian approximation matrix computed from finite gradient differences. RES utilizes stochastic gradients in lieu of deterministic gradients for both, the determination of descent directions and the approximation of the objective function's curvature. Since stochastic gradients can be computed at manageable computational cost RES is realizable and retains the convergence rate advantages of its deterministic counterparts. Convergence results show that lower and upper bounds on the Hessian egeinvalues of the sample functions are sufficient to guarantee convergence to optimal arguments. Numerical experiments showcase reductions in convergence time relative to stochastic gradient descent algorithms and non-regularized stochastic versions of BFGS. An application of RES to the implementation of support vector machines is developed.

  7. Regularized Label Relaxation Linear Regression.

    Science.gov (United States)

    Fang, Xiaozhao; Xu, Yong; Li, Xuelong; Lai, Zhihui; Wong, Wai Keung; Fang, Bingwu

    2018-04-01

    Linear regression (LR) and some of its variants have been widely used for classification problems. Most of these methods assume that during the learning phase, the training samples can be exactly transformed into a strict binary label matrix, which has too little freedom to fit the labels adequately. To address this problem, in this paper, we propose a novel regularized label relaxation LR method, which has the following notable characteristics. First, the proposed method relaxes the strict binary label matrix into a slack variable matrix by introducing a nonnegative label relaxation matrix into LR, which provides more freedom to fit the labels and simultaneously enlarges the margins between different classes as much as possible. Second, the proposed method constructs the class compactness graph based on manifold learning and uses it as the regularization item to avoid the problem of overfitting. The class compactness graph is used to ensure that the samples sharing the same labels can be kept close after they are transformed. Two different algorithms, which are, respectively, based on -norm and -norm loss functions are devised. These two algorithms have compact closed-form solutions in each iteration so that they are easily implemented. Extensive experiments show that these two algorithms outperform the state-of-the-art algorithms in terms of the classification accuracy and running time.

  8. Development of test objects for image quality evaluation of digital mammography

    International Nuclear Information System (INIS)

    Pinto, Vitor Nascimento de Carvalho

    2013-01-01

    Mammography is the image exam called 'gold standard' for early detection of breast cancer. 111 Brazil, more than eight million mammograms are carried out per year. With the advancement of technology, the digital systems CR and DR for this diagnostic modality have been increasingly implemented, replacing the conventional screen-film system, which brought environmental problems, like the disposal of chemical waste, and is also responsible for the rejection of radiographic films with processing artifacts. Digital systems, besides not experiencing the problem of environmental pollution, are still capable of image processing, allowing a much lower rejection rate when compared to the conventional system. Moreover, the determination of an accurate diagnosis is highly dependent on the image quality of the examination. To ensure the reliability of the images produced by these systems, it is necessary to evaluate them on a regular basis. Unfortunately, there is no regulation in Brazil about the Quality Assurance of these systems. The aim of this study was to develop a set of test objects that allow the evaluation of some parameters of image quality of these systems, such as field image uniformity, the linearity between the air Kerma incident on detector and the mean pixel value (MPV) of the image, the spatial resolution of the system through the modulation transfer function (MTF) and also to suggest an object to be applied in the evaluation of contrast-to-noise ratio (CNR) and signal-difference-to-noise ratio (SDNR). In order to test the objects. 10 mammography centers were evaluated, seven with CR systems and three with the DR systems. To evaluate the linearity, besides the test objects high sensitivity dosimeters were necessary to be used, namely LiF:Mg,Cu,P TL dosimeters. The use of these dosimeters was recommended in order to minimize the time required to perform the tests and to decrease the number of exposures needed. For evaluation of digital images in DICOM format

  9. Time for a re-evaluation of mammography in the young? Results of an audit of mammography in women younger than 40 in a resource restricted environment.

    Science.gov (United States)

    Taylor, Liezel; Basro, Sarinah; Apffelstaedt, Justus P; Baatjes, Karin

    2011-08-01

    Mammography in younger women is considered to be of limited value. In a resource restricted environment without access to magnetic resonance imaging (MRI) and with a high incidence of breast cancer in the young, mammography remains an important diagnostic tool. Recent technical advances and better regulation of mammography make a reassessment of its value in these conditions necessary. Data of all the mammograms performed at a tertiary hospital and private breast clinic between January 2003 and July 2009 in women less than 40 years of age were collected. Indications were the presence of a mass, follow-up after primary cancer therapy, and screening for patients perceived at high risk due to a family history or the presence of atypical hyperplasia. Data acquired were as follows: Demographics, prior breast surgery, indication for mammography, outcome of mammography, diagnostic procedures, and their results. Of 2,167 mammograms, 393 were performed for a palpable mass, diagnostic mammography. In these, the overall cancer detection rate was 40%. If the mammography was reported as breast imaging reporting and data system (BIRADS(®)) 5 versus BIRADS(®) 3 and 4 versus BIRADS(®) 1 and 2, a final diagnosis of malignancy was established in 96, 48, and 5%, respectively. Of 367 mammograms done for the follow-up after primary treatment of breast cancer, seven cancers were diagnosed for a detection rate of 1.9%. Of 1,312 mammograms performed for screening, the recall rate was 4%; the biopsy rate 2%, and the cancer diagnosis rate 3/1,000 examinations. In contrast to past series, this series has shown that recent advances in mammography have made it a useful tool in the management of breast problems in young women, notably in a resource-restricted environment. Women for screening should be selected carefully.

  10. Decision making and counseling around mammography screening for women aged 80 or older.

    Science.gov (United States)

    Schonberg, Mara A; Ramanan, Radhika A; McCarthy, Ellen P; Marcantonio, Edward R

    2006-09-01

    Despite uncertain benefit, many women over age 80 (oldest-old) receive screening mammography. To explore decision-making and physician counseling of oldest-old women around mammography screening. Qualitative research using in-depth semi-structured interviews. Twenty-three women aged 80 or older who received care at a large academic primary care practice (13 had undergone mammography screening in the past 2 years) and 16 physicians at the same center. We asked patients and physicians to describe factors influencing mammography screening decisions of oldest-old women. We asked physicians to describe their counseling about screening to the oldest-old. Patients and/or physicians identified the importance of physician influence, patient preferences, system factors, and social influences on screening decisions. Although physicians felt that patient's health affected screening decisions, few patients felt that health mattered. Three types of elderly patients were identified: (1) women enthusiastic about screening mammography; (2) women opposed to screening mammography; and (3) women without a preference who followed their physician's recommendation. However, physician counseling about mammography screening to elderly women varies; some individualize discussions; others encourage screening; few discourage screening. Physicians report that discussions about stopping screening can be uncomfortable and time consuming. Physicians suggest that more data could facilitate these discussions. Some oldest-old women have strong opinions about screening mammography while others are influenced by physicians. Discussions about stopping screening are challenging for physicians. More data about the benefits and risks of mammography screening for women aged 80 or older could inform patients and improve provider counseling to lead to more rational use of mammography.

  11. Micro calcification evaluation using CR plates in computerized mammography

    International Nuclear Information System (INIS)

    Bustos F, M.; Prata M, A.

    2017-10-01

    Cancer is one of the leading causes of mortality in the world. In 2012, about 14 million new cases were registered, of which 1.6 million are breast cancer, according to the World Health Organization. The National Cancer Institute of Brazil estimated 57 thousand new cases of breast cancer by 2016. Mammography is the imaging technique most used worldwide for the early diagnosis of breast cancer. Computed radiography (CR) plates are used for digital radiography, and are widely used to obtain digital mammograms. This work aims to evaluate te response of CR plates to the variation of exposure in mammography equipment. Three CR plates for mammography of different models were used for the study. X-ray beams were selected to perform successive exposures of CR plates by varying the exposure time. These exposures were performed to obtain raw images that were subsequently analyzed using ImageJ software, from which the value of intensity recorded in the central region of each image was obtained, correlating it with the exposure time. From these data the necessary correlations were made to determine the exposure time for which the CR plate begins to saturate, observing that the saturation occurs first for the highest value of the applied voltage. Finally, successive exposures of the CR plate were made using the compressed breast simulator made of acrylic plates and containing microcalcifications of different sizes to determine the qualitative resolution of CR plates, observing that only microcalcifications above 177 μm are visible in the image. The knowledge of saturation characteristics and resolution of the CR plate allows the selection of more adequate parameters to work without approaching the saturation region. (Author)

  12. Quantitative contrast-enhanced mammography for contrast medium kinetics studies

    Science.gov (United States)

    Arvanitis, C. D.; Speller, R.

    2009-10-01

    Quantitative contrast-enhanced mammography, based on a dual-energy approach, aims to extract quantitative and temporal information of the tumour enhancement after administration of iodinated vascular contrast media. Simulations using analytical expressions and optimization of critical parameters essential for the development of quantitative contrast-enhanced mammography are presented. The procedure has been experimentally evaluated using a tissue-equivalent phantom and an amorphous silicon active matrix flat panel imager. The x-ray beams were produced by a tungsten target tube and spectrally shaped using readily available materials. Measurement of iodine projected thickness in mg cm-2 has been performed. The effect of beam hardening does not introduce nonlinearities in the measurement of iodine projected thickness for values of thicknesses found in clinical investigations. However, scattered radiation introduces significant deviations from slope equal to unity when compared with the actual iodine projected thickness. Scatter correction before the analysis of the dual-energy images provides accurate iodine projected thickness measurements. At 10% of the exposure used in clinical mammography, signal-to-noise ratios in excess of 5 were achieved for iodine projected thicknesses less than 3 mg cm-2 within a 4 cm thick phantom. For the extraction of temporal information, a limited number of low-dose images were used with the phantom incorporating a flow of iodinated contrast medium. The results suggest that spatial and temporal information of iodinated contrast media can be used to indirectly measure the tumour microvessel density and determine its uptake and washout from breast tumours. The proposed method can significantly improve tumour detection in dense breasts. Its application to perform in situ x-ray biopsy and assessment of the oncolytic effect of anticancer agents is foreseeable.

  13. Micro calcification evaluation using CR plates in computerized mammography

    Energy Technology Data Exchange (ETDEWEB)

    Bustos F, M.; Prata M, A., E-mail: mabelita.bfm@gmail.com [Federal University of Minas Gerais, School of Engineering, Department of Nuclear Engineering, Av. Antonio Carlos CEP 131270-901 Belo Horizonte, Minas Gerais (Brazil)

    2017-10-15

    Cancer is one of the leading causes of mortality in the world. In 2012, about 14 million new cases were registered, of which 1.6 million are breast cancer, according to the World Health Organization. The National Cancer Institute of Brazil estimated 57 thousand new cases of breast cancer by 2016. Mammography is the imaging technique most used worldwide for the early diagnosis of breast cancer. Computed radiography (CR) plates are used for digital radiography, and are widely used to obtain digital mammograms. This work aims to evaluate te response of CR plates to the variation of exposure in mammography equipment. Three CR plates for mammography of different models were used for the study. X-ray beams were selected to perform successive exposures of CR plates by varying the exposure time. These exposures were performed to obtain raw images that were subsequently analyzed using ImageJ software, from which the value of intensity recorded in the central region of each image was obtained, correlating it with the exposure time. From these data the necessary correlations were made to determine the exposure time for which the CR plate begins to saturate, observing that the saturation occurs first for the highest value of the applied voltage. Finally, successive exposures of the CR plate were made using the compressed breast simulator made of acrylic plates and containing microcalcifications of different sizes to determine the qualitative resolution of CR plates, observing that only microcalcifications above 177 μm are visible in the image. The knowledge of saturation characteristics and resolution of the CR plate allows the selection of more adequate parameters to work without approaching the saturation region. (Author)

  14. Digital mammography screening: average glandular dose and first performance parameters

    International Nuclear Information System (INIS)

    Weigel, S.; Girnus, R.; Czwoydzinski, J.; Heindel, W.; Decker, T.; Spital, S.

    2007-01-01

    Purpose: The Radiation Protection Commission demanded structured implementation of digital mammography screening in Germany. The main requirements were the installation of digital reference centers and separate evaluation of the fully digitized screening units. Digital mammography screening must meet the quality standards of the European guidelines and must be compared to analog screening results. We analyzed early surrogate indicators of effective screening and dosage levels for the first German digital screening unit in a routine setting after the first half of the initial screening round. Materials and Methods: We used three digital mammography screening units (one full-field digital scanner [DR] and two computed radiography systems [CR]). Each system has been proven to fulfill the requirements of the National and European guidelines. The radiation exposure levels, the medical workflow and the histological results were documented in a central electronic screening record. Results: In the first year 11,413 women were screened (participation rate 57.5 %). The parenchymal dosages for the three mammographic X-ray systems, averaged for the different breast sizes, were 0.7 (DR), 1.3 (CR), 1.5 (CR) mGy. 7 % of the screened women needed to undergo further examinations. The total number of screen-detected cancers was 129 (detection rate 1.1 %). 21 % of the carcinomas were classified as ductal carcinomas in situ, 40 % of the invasive carcinomas had a histological size ≤ 10 mm and 61 % < 15 mm. The frequency distribution of pT-categories of screen-detected cancer was as follows: pTis 20.9 %, pT1 61.2 %, pT2 14.7 %, pT3 2.3 %, pT4 0.8 %. 73 % of the invasive carcinomas were node-negative. (orig.)

  15. Using Mammography Screening: Hmong Women’s Perceptions and Beliefs

    Directory of Open Access Journals (Sweden)

    Pang Vang

    2010-01-01

    Full Text Available Breast cancer is the second leading cause of cancer deaths among all women in the United States. Although mammography screening has been shown to be effective in detecting breast cancer, Hmong women, one of the Asian American/Pacific Islander subgroups, have a very low screening rate. The purpose of this study was to explore factors that influence Hmong women‘s willingness to be screened for breast cancer. Grounded Theory methodology guided the analysis of fifteen qualitative interviews with Midwestern Hmong women between the ages of40-64. Regardless of age, length of US residency, and language spoken, the results showed one core theme and three interrelated themes regarding the women‘s decision to seek mammographyscreening. The three interrelated themes of Breast Health Messages, Screening Barriers, and Screening Facilitators can have negative and/or positive influences on the core theme of mammography-screening decision-making processes. The first related theme of Breast HealthMessages included professional and lay breast health messages. The second related theme, Screening Facilitators, included breast health messages from professionals, abnormal findings, social support, risk for getting breast cancer, doctor‘s recommendations, and insurance. The third related theme, Screening Barriers, identified symptomatic health seeking behavior, instrumental barriers, fear, social influence (which included lay breast health messages, use of traditional Hmong healing practices, embarrassment, and perception of breast cancer risk. This study suggested that the healthcare professionals need to use a culturally sensitive and multidisciplinaryapproach to provide breast health education as well as to assess and provide instrumental support, while encouraging social support to influence Hmong women to attain mammography screening.

  16. SU-E-I-88: Mammography Imaging: Does Positioning Matter?

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J; Szabunio, M [University of Kentucky, Lexington, KY (United States)

    2014-06-01

    Purpose: In mammography, compression is imperative for quality images and glandular radiation exposure dose. The thickness of the compressed breast directly determines mammography acquisition parameters. The compressed thickness varies due to variation in technologist practice, even for the same patient imaged at different time. This study is to investigate potential effect of the variation in breast positioning on radiation dose and image quality. Methods: Radiation dose at different thicknesses was measured with a BR-12 breast phantom for both conventional craniocaudal view and tomosynthesis in a Hologic Tomosynthesis mammography system. The CIRS stereotactic needle biopsy training phantom embedded dense masses and microcalcification in various sizes were imaged for image quality evaluation. Radiologists evaluated images. Clinical mammograms from the same patient but acquired at different time were retrospectively retrieved to evaluate potential effects of variation in positioning. Results: Acquisition parameters (kVp and mAs) increase with the increased phantom thickness. Radiation exposure increases following an exponential trend. The stereotactic phantom images showed loss of spatial and contrast resolution with inappropriate positioning. The compressed pressure may not be a good indicator for appropriate positioning. The inclusion of different amount of pectoralis muscle may lead to the same compressed pressure but different compressed thickness. The initial retrospective study of 3 patients showed that there were potential large variations in positioning the same patient at different examination time, resulting in large variations in patient radiation dose and image quality. Conclusion: Variations in patient positioning potentially influence patient radiation dose and image quality. The technologist has the critical responsibility to position patient to provide quality images in spite of different breast and body types. To reduce intra and inter practice

  17. From inactive to regular jogger

    DEFF Research Database (Denmark)

    Lund-Cramer, Pernille; Brinkmann Løite, Vibeke; Bredahl, Thomas Viskum Gjelstrup

    study was conducted using individual semi-structured interviews on how a successful long-term behavior change had been achieved. Ten informants were purposely selected from participants in the DANO-RUN research project (7 men, 3 women, average age 41.5). Interviews were performed on the basis of Theory...... of Planned Behavior (TPB) and The Transtheoretical Model (TTM). Coding and analysis of interviews were performed using NVivo 10 software. Results TPB: During the behavior change process, the intention to jogging shifted from a focus on weight loss and improved fitness to both physical health, psychological......Title From inactive to regular jogger - a qualitative study of achieved behavioral change among recreational joggers Authors Pernille Lund-Cramer & Vibeke Brinkmann Løite Purpose Despite extensive knowledge of barriers to physical activity, most interventions promoting physical activity have proven...

  18. Clear-PEM, a dedicated PET camera for mammography

    CERN Document Server

    Lecoq, P

    2002-01-01

    Preliminary results suggest that Positron Emission Mammography (PEM) can offer a noninvasive method for the diagnosis of breast cancer. Metabolic images from PEM contain unique information not available from conventional morphologic imaging techniques and aid in expeditiously establishing the diagnosis of cancer. A dedicated machine seems to offer better perspectives in terms of position resolution and sensitivity. This paper describes the concept of Clear-PEM, the system presently developed by the Crystal Clear Collaboration at CERN for an evaluation of this approach. This device is based on new crystals introduced by the Crystal Clear as well as on modern data acquisition techniques developed for the large experiments in high energy physics experiments.

  19. Compositional breast imaging using a dual-energy mammography protocol

    International Nuclear Information System (INIS)

    Laidevant, Aurelie D.; Malkov, Serghei; Flowers, Chris I.; Kerlikowske, Karla; Shepherd, John A.

    2010-01-01

    Purpose: Mammography has a low sensitivity in dense breasts due to low contrast between malignant and normal tissue confounded by the predominant water density of the breast. Water is found in both adipose and fibroglandular tissue and constitutes most of the mass of a breast. However, significant protein mass is mainly found in the fibroglandular tissue where most cancers originate. If the protein compartment in a mammogram could be imaged without the influence of water, the sensitivity and specificity of the mammogram may be improved. This article describes a novel approach to dual-energy mammography, full-field digital compositional mammography (FFDCM), which can independently image the three compositional components of breast tissue: water, lipid, and protein. Methods: Dual-energy attenuation and breast shape measures are used together to solve for the three compositional thicknesses. Dual-energy measurements were performed on breast-mimicking phantoms using a full-field digital mammography unit. The phantoms were made of materials shown to have similar x-ray attenuation properties of the compositional compartments. They were made of two main stacks of thicknesses around 2 and 4 cm. Twenty-six thickness and composition combinations were used to derive the compositional calibration using a least-squares fitting approach. Results: Very high accuracy was achieved with a simple cubic fitting function with root mean square errors of 0.023, 0.011, and 0.012 cm for the water, lipid, and protein thicknesses, respectively. The repeatability (percent coefficient of variation) of these measures was tested using sequential images and was found to be 0.5%, 0.5%, and 3.3% for water, lipid, and protein, respectively. However, swapping the location of the two stacks of the phantom on the imaging plate introduced further errors showing the need for more complete system uniformity corrections. Finally, a preliminary breast image is presented of each of the compositional

  20. A procedure for routine radiation protection checking of mammography equipment

    International Nuclear Information System (INIS)

    Bengtsson, L.G.; Lundehn, I.

    1980-01-01

    A procedure was developed for checking of mammography equipment used in screening for mammary cancer. The procedure will be handled by hospital physicists or x-ray inspectors and is intended to permit checking of x-ray equipment performance as well as evaluation of mean dose or eneray imparted to groups of patients. Measurement methods studied involve TLD, ionization chambers and a new plastic scintillator designed to measure energy imparted. After careful study of sizes and attenuation properties of breasts, a 50 mm polymethylmetacrylate phantom seemed the most appropriate. The choice of measuring equipment is reported as well as some preliminary results from field measurements. (author)

  1. The results of a quality-control programme in mammography

    International Nuclear Information System (INIS)

    Ramsdale, M.L.; Hiles, P.A.

    1989-01-01

    A quality-control programme at a breast screening clinic is described. Daily checks include film sensitometry for X-ray processor control and radiography of a lucite phantom to monitor the consistency of the X-ray machine automatic exposure control. Weekly checks include additional measurements on the performance of the automatic exposure control for different breast thickness and an overall assessment of image quality using a prototype mammography test phantom. The test phantom measures low-contrast sensitivity, high-control resolution and small-detail visibility. The results of the quality-control programme are presented with particular attention paid to tolerances and limiting values. (author)

  2. Quantitative dynamic MR-mammography for diagnosis of breast cancer

    International Nuclear Information System (INIS)

    Klengel, S.; Hietschold, V.; Koehler, K.

    1997-01-01

    Problems of screening X-mammography are mainly the so-called 'dense breast', the postoperative status and suspect focal densities. Contrast enhanced MRI was hoped to further improve diagnostic specificity. Unfortunately, contrast enhancement appears in an overlapping manner in both malignant and benign lesions. A restrospective parameter analysis of dynamic early and late phase contrast enhancement showed a threshold based on a linear combination of early and late phase parameters best suited for lesion characterisation. In a prospective study this threshold offered a high specificity without loss of sensitivity in classification of suspect densities. A reduction of unnecessary operations should be possible in future relevant exclusion criteria. (orig.)

  3. In vivo comparison of screen-film mammography and xeromammography

    International Nuclear Information System (INIS)

    Yagan, R.; Skubic, S.E.; Oravec, D.; Green, H.Y.

    1987-01-01

    In vivo comparison of film-screen with grid and xeromammography was performed in 97 patients by three mammographers experienced with both modalities. The results show that file-screen modality is superior to xeromammography in the following areas: (1) in identifying of microcalcifications and determining their topographic characteristics; (2) in visualizing masses; and (3) in visualizing the nipple and entire skin line without artifacts. Both methods were equal in imaging of the parenchyma of dense breasts. The chest wall is somewhat better visualized with xeromammography, without providing any clinical advantage in the cases reviewed. The authors conclude that film-screen mammography with antiscatter grid is the preferred method in breast evaluation

  4. Diagnostic efficacy of mammography in various age groups

    International Nuclear Information System (INIS)

    Tekkel, M.Yu.

    1991-01-01

    The diagnostic efficacy of 935 mammographies from the mammology service for self-referred symptomatic women was assessed for the period of 1975-1988. Breast cancer was detected in 200 women. The paper is concerned with the distribution of true- or false-positive and true- or false-negative mammagraphic diagnoses in the age groups of women under 40, 40 to 49 and over 49. The sensitivity of mammomgraphy in these age groups was 87.5, 72.4 and 89 %, the specificity was 83.5, 76.4 and 83 %, and the positive predictive values were 42, 38,2 and 69.5 %, respectively

  5. Knowledge discovery from structured mammography reports using inductive logic programming.

    Science.gov (United States)

    Burnside, Elizabeth S; Davis, Jesse; Costa, Victor Santos; Dutra, Inês de Castro; Kahn, Charles E; Fine, Jason; Page, David

    2005-01-01

    The development of large mammography databases provides an opportunity for knowledge discovery and data mining techniques to recognize patterns not previously appreciated. Using a database from a breast imaging practice containing patient risk factors, imaging findings, and biopsy results, we tested whether inductive logic programming (ILP) could discover interesting hypotheses that could subsequently be tested and validated. The ILP algorithm discovered two hypotheses from the data that were 1) judged as interesting by a subspecialty trained mammographer and 2) validated by analysis of the data itself.

  6. Tessellating the Sphere with Regular Polygons

    Science.gov (United States)

    Soto-Johnson, Hortensia; Bechthold, Dawn

    2004-01-01

    Tessellations in the Euclidean plane and regular polygons that tessellate the sphere are reviewed. The regular polygons that can possibly tesellate the sphere are spherical triangles, squares and pentagons.

  7. On the equivalence of different regularization methods

    International Nuclear Information System (INIS)

    Brzezowski, S.

    1985-01-01

    The R-circunflex-operation preceded by the regularization procedure is discussed. Some arguments are given, according to which the results may depend on the method of regularization, introduced in order to avoid divergences in perturbation calculations. 10 refs. (author)

  8. The uniqueness of the regularization procedure

    International Nuclear Information System (INIS)

    Brzezowski, S.

    1981-01-01

    On the grounds of the BPHZ procedure, the criteria of correct regularization in perturbation calculations of QFT are given, together with the prescription for dividing the regularized formulas into the finite and infinite parts. (author)

  9. Two Views of Public Participation

    International Nuclear Information System (INIS)

    Blackman, H. S.; Harbour, J. L.

    2002-01-01

    Risk perception has been studied extensively over the past several decades. This research has defined the differences that exist between and among various groups as defined by their education, interests, geographic distribution, and beliefs. It has also been repeatedly demonstrated that various public groups can and do have a tremendous impact on decisions made in the public and private sectors. Involved citizens for example, have caused international corporations as well as the Department of Energy to change or even reverse a chosen course of action. A frequent cause of such reversals is attributed to a lack of involvement of the public and other key decision players directly in the decision process itself. Through our research and case studies, we have developed both an ''as is'' and a ''participatory'' model of decision-making process. The latter decision model allows the direct involvement of important player groups. The paper presents and discusses these models in theoretical and practical terms taken from case studies of the Brent Spar disposal in the North Atlantic, and the use of incineration as a method of waste treatment at the Idaho National Engineering Laboratory. Results from the case studies are used to demonstrate why the ''as is'' model accurately describes the current situation, and how the ''participatory model'' will allow decisions to be made that are publicly supported and can be implemented. The use of such a model will provide users a framework from which to successfully make progress in a wide range of environmental endeavors cooperatively with the public, rather than in spite of the public

  10. Determinants of mammography screening behavior in Iranian women: A population-based study

    Directory of Open Access Journals (Sweden)

    Mitra Moodi

    2012-01-01

    Full Text Available Background: Breast cancer remains a substantial health concern in Iran due to delay and late stage at diagnosis and treatment. Despite the potential benefits of mammography screening for early detection of breast cancer, the performance of this screening among Iranian women is low. For planning appropriate intervention, this study was carried out to identify mammography rates and explore determinants of mammography screening behavior in females of Isfahan, Iran. Materials and Methods: In this population-based study, 384 women of 40 years and older were interviewed by telephone. The Farsi version of Champion′s Health Belief Model scale (CHBMS was used to examine factors associated with mammography screening. The obtained data were analyzed by SPSS (version 16.0 using statistical Chi-square, Fisher Exact test, t-test and multiple logistic regression model to identify the importance rate of socio-demographic and Health Belief Model (HBM variables to predict mammography screening behavior. In all of tests, the level of significant was considered a = 0.05. Results: Mean age ΁ SD of women was 52.24 ΁ 8.2 years. Of the 384 participants, 44.3% reported at least one mammogram in their lifetime. Logistic regression analysis indicated that women were more likely to have mammography if they heard/read about breast cancer (OR = 4.17, 95% CI 2.09, 8.34, menopause in lower age (OR = 0.2, 95% CI 0.87, 0.99 and history of breast problem (OR = 0.9, 95% CI 0.12, 0.32. Also, women who perceived more benefits of mammography (OR = 1.84, 95% CI 1.63, 2.09, fewer barriers of mammography (OR = 0.91, 95% CI 0.86, 0.96 and had more motivation for health (OR = 0.94, 95% CI 0.89, 1 were more likely to have mammography. Conclusion: The findings indicated that the rate of mammography screening among women in Isfahan province is low and highlights the need for developing a comprehensive national breast cancer control program, which should be considered as the first

  11. Application of Turchin's method of statistical regularization

    Science.gov (United States)

    Zelenyi, Mikhail; Poliakova, Mariia; Nozik, Alexander; Khudyakov, Alexey

    2018-04-01

    During analysis of experimental data, one usually needs to restore a signal after it has been convoluted with some kind of apparatus function. According to Hadamard's definition this problem is ill-posed and requires regularization to provide sensible results. In this article we describe an implementation of the Turchin's method of statistical regularization based on the Bayesian approach to the regularization strategy.

  12. Regular extensions of some classes of grammars

    NARCIS (Netherlands)

    Nijholt, Antinus

    Culik and Cohen introduced the class of LR-regular grammars, an extension of the LR(k) grammars. In this report we consider the analogous extension of the LL(k) grammers, called the LL-regular grammars. The relations of this class of grammars to other classes of grammars are shown. Every LL-regular

  13. Computer-aided detection of breast masses: Four-view strategy for screening mammography

    International Nuclear Information System (INIS)

    Wei Jun; Chan Heangping; Zhou Chuan; Wu Yita; Sahiner, Berkman; Hadjiiski, Lubomir M.; Roubidoux, Marilyn A.; Helvie, Mark A.

    2011-01-01

    Purpose: To improve the performance of a computer-aided detection (CAD) system for mass detection by using four-view information in screening mammography. Methods: The authors developed a four-view CAD system that emulates radiologists' reading by using the craniocaudal and mediolateral oblique views of the ipsilateral breast to reduce false positives (FPs) and the corresponding views of the contralateral breast to detect asymmetry. The CAD system consists of four major components: (1) Initial detection of breast masses on individual views, (2) information fusion of the ipsilateral views of the breast (referred to as two-view analysis), (3) information fusion of the corresponding views of the contralateral breast (referred to as bilateral analysis), and (4) fusion of the four-view information with a decision tree. The authors collected two data sets for training and testing of the CAD system: A mass set containing 389 patients with 389 biopsy-proven masses and a normal set containing 200 normal subjects. All cases had four-view mammograms. The true locations of the masses on the mammograms were identified by an experienced MQSA radiologist. The authors randomly divided the mass set into two independent sets for cross validation training and testing. The overall test performance was assessed by averaging the free response receiver operating characteristic (FROC) curves of the two test subsets. The FP rates during the FROC analysis were estimated by using the normal set only. The jackknife free-response ROC (JAFROC) method was used to estimate the statistical significance of the difference between the test FROC curves obtained with the single-view and the four-view CAD systems. Results: Using the single-view CAD system, the breast-based test sensitivities were 58% and 77% at the FP rates of 0.5 and 1.0 per image, respectively. With the four-view CAD system, the breast-based test sensitivities were improved to 76% and 87% at the corresponding FP rates, respectively

  14. Dose and diagnostic performance comparison between phase-contrast mammography with synchrotron radiation and digital mammography: a clinical study report.

    Science.gov (United States)

    Fedon, Christian; Rigon, Luigi; Arfelli, Fulvia; Dreossi, Diego; Quai, Elisa; Tonutti, Maura; Tromba, Giuliana; Cova, Maria Assunta; Longo, Renata

    2018-01-01

    Two dosimetric quantities [mean glandular dose (MGD) and entrance surface air kerma (ESAK)] and the diagnostic performance of phase-contrast mammography with synchrotron radiation (MSR) are compared to conventional digital mammography (DM). Seventy-one patients (age range, 41 to 82 years) underwent MSR after a DM examination if questionable or suspicious breast abnormalities were not clarified by ultrasonography. The MGD and the ESAK delivered in both examinations were evaluated and compared. Two on-site radiologists rated the images in consensus according to the Breast Imaging Reporting and Data System assessment categories, which were then correlated with the final diagnoses by means of statistical generalized linear models (GLMs). Receiver operating characteristic curves were also used to assess the diagnostic performance by comparing the area under the curve (AUC). An important MGD and ESAK reduction was observed in MSR due to the monoenergetic beam. In particular, an average 43% reduction was observed for the MGD and a reduction of more than 50% for the ESAK. GLM showed higher diagnostic accuracy, especially in terms of specificity, for MSR, confirmed by AUC analysis ([Formula: see text]). The study design implied that the population was characterized by a high prevalence of disease and that the radiologists, who read the DM images before referring the patient to MSR, could have been influenced in their assessments. Within these limitations, the use of synchrotron radiation with the phase-contrast technique applied to mammography showed an important dose reduction and a higher diagnostic accuracy compared with DM. These results could further encourage research on the translation of x-ray phase-contrast imaging into the clinics.

  15. Digital mammography: what do we and what don't we know?

    International Nuclear Information System (INIS)

    Bick, Ulrich; Diekmann, Felix

    2007-01-01

    High-quality full-field digital mammography has been available now for several years and is increasingly used for both diagnostic and screening mammography. A number of different detector technologies exist, which all have their specific advantages and disadvantages. Diagnostic accuracy of digital mammography has been shown to be at least equivalent to film-screen mammography in a general screening population. Digital mammography is superior to screen-film mammography in younger women with dense breasts due to its ability to selectively optimize contrast in areas of dense parenchyma. This advantage is especially important in women with a genetic predisposition for breast cancer, where intensified early detection programs may have to start from 25 to 30 years of age. Tailored image processing and computer-aided diagnosis hold the potential to further improve the early detection of breast cancer. However, at present no consensus exists among radiologists on which processing is optimal for digital mammograms. Image processing may also vary significantly among vendors with so far limited interoperability. This review aims to summarize the available information regarding the impact of digital mammography on workflow and breast cancer diagnosis. (orig.)

  16. Promoting mammography screening among Chinese American women using a message-framing intervention.

    Science.gov (United States)

    Sun, Yiyuan; Sarma, Elizabeth A; Moyer, Anne; Messina, Catherine R

    2015-07-01

    This study examined the role of women's perceptions about the relative pros versus cons (decisional balance) of mammography in moderating Chinese American women's responses to gain- and loss-framed messages that promote mammography. One hundred and forty-three Chinese American women who were currently nonadherent to guidelines for receiving annual screening mammograms were randomly assigned to read either a gain- or loss-framed culturally appropriate print brochure about mammography screening. Mammography screening was self-reported at a 2-month follow-up. Although there was not a main effect for message frame, the hypothesized interaction between message frame and decisional balance was significant, indicating that women who received a framed message that matched their decisional balance were significantly more likely to have obtained a mammogram by the follow-up than women who received a mismatched message. Results suggest that decisional balance, and more generally, perceptions about mammography, may be an important moderator of framing effects for mammography among Chinese American women. The match between message frame and decisional balance should be considered when attempting to encourage Chinese American women to receive mammography screening, as a match between the two may be most persuasive. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  17. TU-CD-207-04: Radiation Exposure Comparisons of CESM with 2D FFDM and 3D Tomosynthesis Mammography

    Energy Technology Data Exchange (ETDEWEB)

    James, J; Boltz, T; Pavlicek, W [Mayo Clinic Arizona, Scottsdale, AZ (United States)

    2015-06-15

    Purpose: While mammography is considered the standard for front-line breast cancer screening, image sensitivity and specificity can be affected by factors like dense breast tissue. Contrast-enhanced spectral mammography (CESM) shows promising initial results for dense breasts but comes at the cost of increased dose compared with full-field-digital-mammography (FFDM). The goal of this study is to quantitatively assess the dose increase of CESM in comparison with 2D-FFDM and 3D-Tomo at varying breast thickness. Methods: The experiments were conducted on a Hologic-Selenia-Dimensions system that performed 2D-FFDM, 3D-Tomo and CESM (high and low energies) on regular (50/50) and dense (70/30) breast tissue-mimicking phantoms. Both the phantoms had 6, 1-cm thick slabs (total thickness 6cm), compressed at 20-lbs using an 18×24 paddle. A single exposure was performed for each of the 3 mammo techniques with the following settings: AEC-Auto; Focal Spot-Large; kVp-Auto; mAs- Auto, Target/Filter combination-Auto; AEC Sensor/Exposure compensation Step-2/0. Average glandular dose (AGD) in mGy was obtained and compared as a function of breast thickness (1 – 6 cm) for both the phantom types. Results: The study shows that dose from the total CESM from 50/50 phantom at a breast thickness of a) 4.5 cm was 37.5% higher than 2D-FFDM and 30% higher than 3D-Tomo, b) 6 cm was 36.2% higher than 2D-FFDM and 41% higher than 3D-Tomo. For a dense breast tissue of 70/30 phantom, it was found that CESM dose at a breast thickness of: a) 4.5 cm was 33.3% higher than 2D-FFDM and 28.8% higher than 3D-Tomo, b) 6 cm was 35.4% higher than 2D-FFDM and 48.0% higher than 3D-Tomo. The overall CESM dose for the dense breast phantom was 12.5% higher at 4.5cm and 35% higher at 6 cm compared to the 50/50 phantom. Conclusion: This quantitative comparison study showed that CESM technique has an increased radiation dose compared to conventional 2D-FFDM and 3D-Tomo.

  18. Proliferative changes in nonpalpable breast lesions detected by mammography

    International Nuclear Information System (INIS)

    Vega, A.; Delgado, A.; Ortega, E.; Garijo, F.; Mosquera, J.; Sogo, C.; Alvarez, A.

    2000-01-01

    To analyze retrospectively the radiological findings in nonpalpable breast lesions detected by mammography that lead to the performance of surgical biopsy, resulting in a histological diagnosis of proliferative breast disease with and without atypia. From two Spanish hospitals, 421 women with 429 biopsies indicative of the presence of proliferative breast disease with and without atypia were selected out of a total of 1252 surgical biopsies in nonpalpable lesions that proved to be benign. Age, personal and familial history of breast cancer, reason for requesting the mammography and radiological findings that had indicated the need for surgical biopsy were recorded for each patient. The diagnosis was proliferative breast disease (epithelial hyperplasia) in 347 women with 354 biopsies and atypical hyperplasia in the remaining 74 women with 75 biopsies, representing 28% and 6%, respectively, of the 1252 biopsies of lesions found to be benign. In 221 of the 354 cases of epithelial hyperplasia (62%) and 45 of the 75 cases of atypical hyperplasia (60%), the presence of calcifications was the most common radiological findings leading to biopsy (p<0.05). Parenchymal distortion, with or without calcifications, was the second most common radiological sign. The histological study revealed a close relationship between these proliferative events and radial scars. Calcifications are the radiological finding that most frequently indicate the need for surgical biopsy in nonpalpable lesions that results in a diagnosis of proliferative breast disease with and without atypia. (Author) 12 refs

  19. Breast compression in mammography: how much is enough?

    Science.gov (United States)

    Poulos, Ann; McLean, Donald; Rickard, Mary; Heard, Robert

    2003-06-01

    The amount of breast compression that is applied during mammography potentially influences image quality and the discomfort experienced. The aim of this study was to determine the relationship between applied compression force, breast thickness, reported discomfort and image quality. Participants were women attending routine breast screening by mammography at BreastScreen New South Wales Central and Eastern Sydney. During the mammographic procedure, an 'extra' craniocaudal (CC) film was taken at a reduced level of compression ranging from 10 to 30 Newtons. Breast thickness measurements were recorded for both the normal and the extra CC film. Details of discomfort experienced, cup size, menstrual status, existing breast pain and breast problems were also recorded. Radiologists were asked to compare the image quality of the normal and manipulated film. The results indicated that 24% of women did not experience a difference in thickness when the compression was reduced. This is an important new finding because the aim of breast compression is to reduce breast thickness. If breast thickness is not reduced when compression force is applied then discomfort is increased with no benefit in image quality. This has implications for mammographic practice when determining how much breast compression is sufficient. Radiologists found a decrease in contrast resolution within the fatty area of the breast between the normal and the extra CC film, confirming a decrease in image quality due to insufficient applied compression force.

  20. The personal costs and convenience of screening mammography.

    Science.gov (United States)

    Suter, Lisa Gale; Nakano, Connie Y; Elmore, Joann G

    2002-09-01

    Few studies have examined the impact of women's personal costs on obtaining a screening mammogram in the United States. All women obtaining screening mammograms at nine Connecticut mammography facilities during a 2-week study period were asked to complete a questionnaire. Facilities included urban and rural fixed sites and mobile sites. The survey included questions about insurance coverage, mammogram payment, and personal costs in terms of transportation, family care, parking, and lost work time from the women's perspective. The response rate was 62% (731 of 1189). Thirty-two percent of respondents incurred some type of personal cost, including lost work time, family care, and parking. Women incurring personal costs were more likely than those without personal costs to attend an urban facility (46% vs. 23%, p convenience and 17% listed cost as a reason for choosing a mammography facility; 23% reported that cost might prevent them from obtaining a future mammogram. One third of women obtaining mammograms may be incurring personal costs. These personal costs should be considered in future cost-effectiveness analyses.

  1. Mammographic density measurements are not affected by mammography system.

    Science.gov (United States)

    Damases, Christine N; Brennan, Patrick C; McEntee, Mark F

    2015-01-01

    Mammographic density (MD) is a significant risk factor for breast cancer and has been shown to reduce the sensitivity of mammography screening. Knowledge of a woman's density can be used to predict her risk of developing breast cancer and personalize her imaging pathway. However, measurement of breast density has proven to be troublesome with wide variations in density recorded using radiologists' visual Breast Imaging Reporting and Data System (BIRADS). Several automated methods for assessing breast density have been proposed, each with their own source of measurement error. The use of differing mammographic imaging systems further complicates MD measurement, especially for the same women imaged over time. The purpose of this study was to investigate whether having a mammogram on differing manufacturer's equipment affects a woman's MD measurement. Raw mammographic images were acquired on two mammography imaging systems (General Electric and Hologic) one year apart and processed using VolparaDensity™ to obtain the Volpara Density Grade (VDG) and average volumetric breast density percentage (AvBD%). Visual BIRADS scores were also obtained from 20 expert readers. BIRADS scores for both systems showed strong positive correlation ([Formula: see text]; [Formula: see text]), while the VDG ([Formula: see text]; [Formula: see text]) and AvBD% ([Formula: see text]; [Formula: see text]) showed stronger positive correlations. Substantial agreement was shown between the systems for BIRADS ([Formula: see text]; [Formula: see text]), however, the systems demonstrated an almost perfect agreement for VDG ([Formula: see text]; [Formula: see text]).

  2. Breast screening with mammography: Overview of Swedish randomized trials

    International Nuclear Information System (INIS)

    Nystroem, L.; Wall, S.; Lindqvist, M.; Ryden, S.; Andersson, J.; Bjurstam, N.; Fagerberg, G.; Frisell, J.; Tabar, L.; Larson, L.G.

    1993-01-01

    Despite encouraging results from screening trials the efficacy of mammography in reducing mortality remains somewhat controversial. Five studies have been done in Sweden. This overview, reveals a 24% significant reduction of breast cancer mortality among those invited to mammography screening compared with those not invited. To avoid the potential risk of differential misclassification causes of death were assessed by an independent end-point committee after a blinded review of all fatal breast cancer cases. The mortality reduction was similar, irrespective of the end-point used for evaluation (breast cancer as underlying cause of death or breast cancer present at death). There was a consistent risk reduction associated with screening in all studies, although the point estimate of the relative risk for all ages varied non-significantly between 0.68 and 0.84. The cumulative breast cancer mortality by time since randomization was estimated at 1.3 per 1,000 within 6 years in the invited group compared with 1.6 in the control group. The corresponding figures after 9 years are 2.6 and 3.3 and after 12 years 3.9 and 5.1

  3. Comparison between breast MRI and contrast-enhanced spectral mammography.

    Science.gov (United States)

    Łuczyńska, Elżbieta; Heinze-Paluchowska, Sylwia; Hendrick, Edward; Dyczek, Sonia; Ryś, Janusz; Herman, Krzysztof; Blecharz, Paweł; Jakubowicz, Jerzy

    2015-05-12

    The main goal of this study was to compare contrast-enhanced spectral mammography (CESM) and breast magnetic resonance imaging (MRI) with histopathological results and to compare the sensitivity, accuracy, and positive and negative predictive values for both imaging modalities. After ethics approval, CESM and MRI examinations were performed in 102 patients who had suspicious lesions described in conventional mammography. All visible lesions were evaluated independently by 2 experienced radiologists using BI-RADS classifications (scale 1-5). Dimensions of lesions measured with each modality were compared to postoperative histopathology results. There were 102 patients entered into CESM/MRI studies and 118 lesions were identified by the combination of CESM and breast MRI. Histopathology confirmed that 81 of 118 lesions were malignant and 37 were benign. Of the 81 malignant lesions, 72 were invasive cancers and 9 were in situ cancers. Sensitivity was 100% with CESM and 93% with breast MRI. Accuracy was 79% with CESM and 73% with breast MRI. ROC curve areas based on BI-RADS were 0.83 for CESM and 0.84 for breast MRI. Lesion size estimates on CESM and breast MRI were similar, both slightly larger than those from histopathology. Our results indicate that CESM has the potential to be a valuable diagnostic method that enables accurate detection of malignant breast lesions, has high negative predictive value, and a false-positive rate similar to that of breast MRI.

  4. Contrast-enhanced spectral mammography in patients with MRI contraindications.

    Science.gov (United States)

    Richter, Vivien; Hatterman, Valerie; Preibsch, Heike; Bahrs, Sonja D; Hahn, Markus; Nikolaou, Konstantin; Wiesinger, Benjamin

    2017-01-01

    Background Contrast-enhanced spectral mammography (CESM) is a novel breast imaging technique providing comparable diagnostic accuracy to breast magnetic resonance imaging (MRI). Purpose To show that CESM in patients with MRI contraindications is feasible, accurate, and useful as a problem-solving tool, and to highlight its limitations. Material and Methods A total of 118 patients with MRI contraindications were examined by CESM. Histology was obtained in 94 lesions and used as gold standard for diagnostic accuracy calculations. Imaging data were reviewed retrospectively for feasibility, accuracy, and technical problems. The diagnostic yield of CESM as a problem-solving tool and for therapy response evaluation was reviewed separately. Results CESM was more accurate than mammography (MG) for lesion categorization (r = 0.731, P < 0.0001 vs. r = 0.279, P = 0.006) and for lesion size estimation (r = 0.738 vs. r = 0.689, P < 0.0001). Negative predictive value of CESM was significantly higher than of MG (85.71% vs. 30.77%, P < 0.0001). When used for problem-solving, CESM changed patient management in 2/8 (25%) cases. Superposition artifacts and timing problems affected diagnostic utility in 3/118 (2.5%) patients. Conclusion CESM is a feasible and accurate alternative for patients with MRI contraindications, but it is necessary to be aware of the method's technical limitations.

  5. Evaluation of patient dose in some mammography centres in Iran

    International Nuclear Information System (INIS)

    Paknyat, A.; Samarin, E. R. P.; Jeshvaghane, N. A.; Paydar, R.; Fasaei, B.; Karamloo, A.; Khosravi, H. R.; Deevband, M. R.

    2011-01-01

    High diagnostic sensitivity and specificity while maintaining the least dose to the patient is the ideal mammography. The objective of this work was to evaluate patient dose and image quality of mammograms to propose corrective actions. The image quality for 1242 patient in 7 mammography facilities in Tehran city was evaluated based on selected image quality criteria using a three-point scale. Clinical image quality, the entrance surface air kerma, the average glandular dose and optical density of films for standard PMMA phantom of 4.5 cm thickness were evaluated. The results showed that up to 72 % of mammograms were in good condition to be diagnosed, and only about 3.4 % of the images were unacceptable or with suboptimal quality. The entrance surface air kerma values were in the range of 3.8-10.5 mGy, average glandular dose 0.5-1.8 mGy and optical density of films 0.74-2.03. The image quality evaluation after correction actions, periodic image quality evaluation and using the correct equipment certainly will improve patient dose. (authors)

  6. Dose and risk evaluation in digital mammography using computer modeling

    International Nuclear Information System (INIS)

    Correa, Samanda Cristine Arruda; Souza, Edmilson Monteiro de; Silva, Humberto de Oliveira; Silva, Ademir Xavier da; Lopes, Ricardo Tadeu; Magalhaes, Sarah Braga

    2010-01-01

    Digital mammography has been introduced in several countries in the last years. The new technology requires new optimising methods considering for instance the increased possibility of changing the absorbed dose, mainly in modern mammographic systems that allow the operator to choose the beam quality by varying the tube voltage, and filter and target materials. In this work, the Monte Carlo code MCNPX is used in order to investigate how the average glandular dose vary with tube voltage (23-32 kV) and anode-filter combination (Mo-Mo,Mo-Rh and Rh-Rh) in digital mammographic examinations. Furthermore, the risk of breast cancer incidence attributable to mammography exams was estimated using the Biological Effects of Ionizing Radiations (BEIR) VII Committee Report. The results show that the risk of breast cancer incidence in women younger than 30 years of age tends to decrease significantly using Rh-Rh anode-filter combination and higher tube voltage. For women older than 50 years of age the variation of tube voltage, and anode-filter combination did not influence the risk values considerably. (author)

  7. Ergonomic strategies to improve radiographers' posture during mammography activities.

    Science.gov (United States)

    Cernean, Nicolai; Serranheira, Florentino; Gonçalves, Pedro; Sá Dos Reis, Cláudia

    2017-08-01

    To identify alternatives for radiographers' postures while performing mammography that can contribute to reduce the risk of work-related musculoskeletal disorders (WRMSDs). Radiographers' postures to positioning craniocaudal (CC) and mediolateral oblique (MLO) views were simulated without any intervention for three scenarios: radiographer/patient with similar statures, radiographer smaller than patient and radiographer taller than patient. Actions were taken to modify the postures: seated radiographer; patient on a step; seated patient; radiographer on a step. All the postures were analysed using kinovea 0.8.15 software and the angles were measured twice and classified according to European standard EN1005-4: 2005. The non-acceptable angles were measured mainly during MLO positioning when radiographer was taller than the patient: 139° and 120° for arm-flexion and abduction, 72° for trunk and -24° for head/neck-flexion. The introduction of alternative postures (radiographer seated), allowed improvements in posture (60° and 99° for arm flexion and abduction, 14° for trunk and 0° for head/neck flexion), being classified as acceptable. The alternative postures simulated have the potential to reduce the risk of developing WRMSDs when radiographers and patients have different statures. • Radiographers' postures in mammography can contribute to work-related musculoskeletal disorders • Non-acceptable posture was identified for MLO breast positioning (radiographer taller than patient) • Adapting posture to patient biotype reduces the WRMSD risk for radiographers.

  8. High-speed large angle mammography tomosynthesis system

    Science.gov (United States)

    Eberhard, Jeffrey W.; Staudinger, Paul; Smolenski, Joe; Ding, Jason; Schmitz, Andrea; McCoy, Julie; Rumsey, Michael; Al-Khalidy, Abdulrahman; Ross, William; Landberg, Cynthia E.; Claus, Bernhard E. H.; Carson, Paul; Goodsitt, Mitchell; Chan, Heang-Ping; Roubidoux, Marilyn; Thomas, Jerry A.; Osland, Jacqueline

    2006-03-01

    A new mammography tomosynthesis prototype system that acquires 21 projection images over a 60 degree angular range in approximately 8 seconds has been developed and characterized. Fast imaging sequences are facilitated by a high power tube and generator for faster delivery of the x-ray exposure and a high speed detector read-out. An enhanced a-Si/CsI flat panel digital detector provides greater DQE at low exposure, enabling tomo image sequence acquisitions at total patient dose levels between 150% and 200% of the dose of a standard mammographic view. For clinical scenarios where a single MLO tomographic acquisition per breast may replace the standard CC and MLO views, total tomosynthesis breast dose is comparable to or below the dose in standard mammography. The system supports co-registered acquisition of x-ray tomosynthesis and 3-D ultrasound data sets by incorporating an ultrasound transducer scanning system that flips into position above the compression paddle for the ultrasound exam. Initial images acquired with the system are presented.

  9. Future of mammography-based imaging; Zukunft mammographiebasierter Bildgebung

    Energy Technology Data Exchange (ETDEWEB)

    Schulz-Wendtland, R.; Brehm, B.; Meier-Meitinger, M.; Uder, M. [Klinikum der Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Gynaekologische Radiologie, Radiologisches Institut, Erlangen (Germany); Wittenberg, T. [Fraunhofer-Institut fuer Integrierte Schaltkreise IIS, Erlangen (Germany); Michel, T.; Anton, G. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Erlangen Centre for Astroparticle Physics, Erlangen (Germany); Hartmann, A. [Klinikum der Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Institut fuer Pathologie, Erlangen (Germany); Beckmann, M.W.; Rauh, C.; Jud, S.M.; Fasching, P.A. [Klinikum der Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Frauenklinik, Comprehensive Cancer Center Erlangen-EMN, Erlangen (Germany)

    2014-03-15

    Mammography is the central diagnostic method for clinical diagnostics of breast cancer and the breast cancer screening program. In the clinical routine complementary methods, such as ultrasound, tomosynthesis and optional magnetic resonance imaging (MRI) are already combined for the diagnostic procedure. Future developments will utilize investigative procedures either as a hybrid (combination of several different imaging modalities in one instrument) or as a fusion method (the technical fusion of two or more of these methods) to implement fusion imaging into diagnostic algorithms. For screening there are reasonable hypotheses to aim for studies that individualize the diagnostic process within the screening procedure. Individual breast cancer risk prediction and individualized knowledge about sensitivity and specificity for certain diagnostic methods could be tested. The clinical implementation of these algorithms is not yet in sight. (orig.) [German] Die Mammographie ist die zentrale diagnostische Methode der klinischen symptombezogenen Abklaerung von Brusterkrankungen und des Brustkrebsscreenings. In der klinischen Diagnostik wird sie heute schon oft durch zusaetzliche Untersuchungsmethoden wie dem Ultraschall, der Tomosynthese und ggf. auch der MRT-Bildgebung unterstuetzt. Zukuenftige Entwicklungen gehen in die Richtung, dass diese Kombination aus 2 oder mehr Untersuchungsverfahren entweder in Hybrid- (Aufnahme mehrerer unterschiedlicher Bildmodalitaeten in einem einzigen Geraet) oder in Fusionsmethoden (Zusammenfuehrung und Registrierung von Bilddaten aus verschiedenen Modalitaeten) technisch professionalisiert werden. Des Weiteren koennten an subgruppenbezogene Erkrankungsrisiken und individuelle Sensitivitaeten und Spezifitaeten angepasste Diagnostikkombinationen fuer eine Screeningdiagnostik Gegenstand kuenftiger Studien sein. Wir stellen die aktuellen Entwicklungen auf diesen Gebieten und deren momentane Relevanz fuer die klinische Praxis und

  10. Effectiveness of mammography boot camp for radiology residents

    International Nuclear Information System (INIS)

    Kim, Keum Won; Kim, Young Joong; Seo, Jae Young

    2017-01-01

    To evaluate an educational effect of the mammography boot camp (MBC) for radiology residents and analyze affecting factors. Between December 2014 and February 2015, radiology residents in 16 institutions performed the MBC program. We compared the educational effect (score difference between pre- and post-camp test) using 25 case series and analyzed the affecting factors including institution, grades of residents, training periods, presence of sub-specialized breast staff, breast density, and types of cases. The mean scores of 92 residents were 52.80 ± 18.10 and 72.50 ± 12.91 in the pre- and post-camp test, respectively (p = 0.001). There was no significant difference of educational effect according to institution (19.70 ± 16.31), grade, or training period. Although the educational effect of non-trainees was superior to that of trainees (28.10 ± 17.55 vs. 15.90 ± 14.22; p = 0.001), the scores of trainees were higher than those of non-trainees. The diagnostic accuracy showed more improvement in a fatty breast and cases with microcalcifications than compared with others. The MBC showed an effective educational result for radiology residents when interpretating a mammography. It was helpful even for non-trainees. The institution, grades training period, and presence of sub-specialized breast staff did not affect the educational effect

  11. Tumour forms and microcalcifications as radiological diagnostic criteria of mammography

    International Nuclear Information System (INIS)

    Cullmann, H.

    1979-01-01

    289 cases of breast carcinoma which had occurred over a period of 7 years were examined at mammograms and histological preparations. Especially in view were the frequency of radiologically visible criteria of malignancy with special stress laid on microcalcifications, typical radiological forms of imaging the various sorts of carcinoma, and a statement on the definiteness of diagnoses made with mammography. The exactness of diagnoses of breast cancer established by means of mammography can be states as 96.9% in 289 cases of carcinoma. 81.7% were assessed as definitely malignant and 15.2% were suspected to be malignant. In these cases, surgery confirmed the teutative diagnosis. 3.1% of the cases must be seen as mammographic false diagnoses in the sense of ''false negative''. These percentages are in correspondence with those obtained by other examiners. The radiologically visible growth form of breast cancer often typically reflect the histomorphological sort of the cancer. In 174 (67.1%) of 259 cases, the histological type of carcinoma could be recognized from the radiologically visible growth form. (orig./MG) [de

  12. Dose and risk evaluation in digital mammography using computer modeling

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Samanda Cristine Arruda; Souza, Edmilson Monteiro de, E-mail: scorrea@nuclear.ufrj.b, E-mail: emonteiro@nuclear.ufrj.b [Centro Universitario Estadual da Zona Oeste (CCMAT/UEZO), Rio de Janeiro, RJ (Brazil); Silva, Humberto de Oliveira, E-mail: hbetorj@gmail.co [Universidade Federal do Rio de Janeiro IF/UFRJ, RJ (Brazil). Inst. de Fisica; Silva, Ademir Xavier da; Lopes, Ricardo Tadeu; Magalhaes, Sarah Braga, E-mail: ademir@nuclear.ufrj.b, E-mail: ricardo@lin.ufrj.b, E-mail: smagalhaes@nuclear.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Nuclear

    2010-07-01

    Digital mammography has been introduced in several countries in the last years. The new technology requires new optimising methods considering for instance the increased possibility of changing the absorbed dose, mainly in modern mammographic systems that allow the operator to choose the beam quality by varying the tube voltage, and filter and target materials. In this work, the Monte Carlo code MCNPX is used in order to investigate how the average glandular dose vary with tube voltage (23-32 kV) and anode-filter combination (Mo-Mo,Mo-Rh and Rh-Rh) in digital mammographic examinations. Furthermore, the risk of breast cancer incidence attributable to mammography exams was estimated using the Biological Effects of Ionizing Radiations (BEIR) VII Committee Report. The results show that the risk of breast cancer incidence in women younger than 30 years of age tends to decrease significantly using Rh-Rh anode-filter combination and higher tube voltage. For women older than 50 years of age the variation of tube voltage, and anode-filter combination did not influence the risk values considerably. (author)

  13. Factors associated with breast arterial calcification on mammography

    International Nuclear Information System (INIS)

    Zafar, A.N.; Khan, S.; Zafar, S.N.

    2013-01-01

    Objective: To determine the frequency of breast arterial calcifications (BAC) as seen on mammographic examination and to determine the association between BAC and hypertension, age, parity and weight of the person. Study Design: Cross-sectional analytic study. Place and Duration of Study: Department of Diagnostic Radiology, Military Hospital, Rawalpindi, from January 2006 to January 2007. Methodology: Two hundred patients undergoing mammography were studied to evaluate the association of BAC with raised blood pressure, age and parity. Previous history of lactation and the patients' weight were also recorded. Proportions of classes were compared using chi-square test. Results: 13.5% of the subjects (n = 200) were positive for BAC on mammograms. Mean age of the BAC positive subjects was higher than their counterparts found negative for BAC. Women bearing 5 - 6 children showed the highest frequency of BAC. Seventy seven (10.38%) of the BAC positive cases had previous history of lactation, whereas 15.44% (n = 123) had not breast fed their children and showed BAC. No significant association of presence of BAC was noted with the weight of the subjects. Conclusion: The frequency of presence of BAC on mammography was associated with systemic hypertension and higher age. It also increased with the reproductive parameters of a woman. (author)

  14. Transformative learning theory: facilitating mammography screening in rural women.

    Science.gov (United States)

    Purtzer, Mary Anne; Overstreet, Lindsey

    2014-03-01

    To use transformative learning to investigate what experiences serve as catalysts for mammography screening, the cognitive and affective responses that result from the catalyst, and how screening behavior is impacted. A descriptive qualitative study. Southeastern Wyoming. 25 low-income, rural women aged 40 years and older. Four focus group interviews. Cancer experiences triggered universal responses of fear by screeners and nonscreeners. The manner in which that fear response was interpreted was a critical factor in the facilitation of, or impedance to, screening. Dichotomous interpretations of fear responses provided the context for screening behavior. Immobilizing and isolating experiences were associated with nonscreening behavior, whereas motivation and self-efficacy were associated with screening behavior. Transformative learning theory is a useful framework from which to explain differences in mammography screening behavior. Creating opportunities that facilitate dialogue and critical reflection hold the potential to change immobilizing and isolating frames of reference in nonscreening women. To help women transcend their fear and become self-efficacious, nurses can assess how cancer and the screening experience is viewed and, if indicated, move beyond standard education and offer opportunities for dialogue and critical reflection.

  15. Effectiveness of mammography boot camp for radiology residents

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Keum Won; Kim, Young Joong; Seo, Jae Young [Dept. of Radiology, Konyang University Hospital, Daejeon (Korea, Republic of); and others

    2017-01-15

    To evaluate an educational effect of the mammography boot camp (MBC) for radiology residents and analyze affecting factors. Between December 2014 and February 2015, radiology residents in 16 institutions performed the MBC program. We compared the educational effect (score difference between pre- and post-camp test) using 25 case series and analyzed the affecting factors including institution, grades of residents, training periods, presence of sub-specialized breast staff, breast density, and types of cases. The mean scores of 92 residents were 52.80 ± 18.10 and 72.50 ± 12.91 in the pre- and post-camp test, respectively (p = 0.001). There was no significant difference of educational effect according to institution (19.70 ± 16.31), grade, or training period. Although the educational effect of non-trainees was superior to that of trainees (28.10 ± 17.55 vs. 15.90 ± 14.22; p = 0.001), the scores of trainees were higher than those of non-trainees. The diagnostic accuracy showed more improvement in a fatty breast and cases with microcalcifications than compared with others. The MBC showed an effective educational result for radiology residents when interpretating a mammography. It was helpful even for non-trainees. The institution, grades training period, and presence of sub-specialized breast staff did not affect the educational effect.

  16. Estimation of mean glandular dose for patients who undergo mammography and studying the factors affecting it

    Science.gov (United States)

    Barzanje, Sana L. N. H.; Harki, Edrees M. Tahir Nury

    2017-09-01

    The objective of this study was to determine mean glandular dose (MGD) during diagnostic mammography. This study was done in two hospitals in Hawler city in Kurdistan -region /Iraq, the exposure parameters kVp and mAs was recorded for 40 patients under go mammography. The MGD estimated by multiplied ESD with normalized glandular dose (Dn). The ESD measured indirectly by measuring output radiation mGy/mAs by using PalmRAD 907 as a suitable detector (Gigger detector).the results; shown that the mean and its standard deviation of MGD for Screen Film Mammography and Digital Mammography are (0.95±0.18)mGy and (0.99±0.26)mGy, respectively. And there is a significant difference between MGD for Screen Film Mammography and Digital Mammography views (p≤0. 05). Also the mean value and its standard deviation of MGD for screen film mammography is (0.96±0.21) for CC projection and (1.03±0.3) mGy for MLO projection, but mean value and its standard deviation evaluated of MGD for digital mammography is (0.92±0.17) mGy for CC projection and (0.98±0.2) mGy for MLO projection. As well as, the effect of kVp and mAs in MGD were studied, shows that in general as kVp and mAs increased the MGD increased accordingly in both of mammography systems.

  17. European radiographers' challenges from mammography education and clinical practice - an integrative review.

    Science.gov (United States)

    Metsälä, Eija; Richli Meystre, Nicole; Pires Jorge, José; Henner, Anja; Kukkes, Tiina; Sá Dos Reis, Cláudia

    2017-06-01

    This study aims to identify European radiographers' challenges in clinical performance in mammography and the main areas of mammography that require more and better training. An extensive search was performed to identify relevant studies focused on clinical practice, education and training in mammography published between January 2010 and December 2015 in the English language. The data were analysed by using deductive thematic analysis. A total of 27 full text articles were read, evaluating their quality. Sixteen articles out of 27 were finally selected for this integrative review. The main challenges of radiographers' mammography education/training can be divided into three groups: training needs, challenges related to radiographers, and challenges related to the organization of education. The most common challenges of clinical performance in mammography among European radiographers involved technical performance, the quality of practices, and patient-centeredness. The introduction of harmonized mammography guidelines across Europe may serve as an evidence-based tool to be implemented in practice and education. However, the variability in human and material resources as well as the different cultural contexts should be considered during this process. • Radiographers' awareness of their professional identity and enhancing multiprofessional cooperation in mammography. • Radiographers' responsibilities regarding image quality (IQ) and optimal breast imaging performance. • Patient-centred mammography services focusing on the psychosocial needs of the patient. • Challenges: positioning, QC-testing, IQ-assessment, optimization of breast compression, communication, teamwork, and patient-centred care. • Introduction of evidence-based guidelines in Europe to harmonize mammography practice and education.

  18. Compilation of historical dose to the breast received during mammography

    International Nuclear Information System (INIS)

    Thierry-Chef, Isabelle; Cardis, Elisabeth; Simon, Steven L.; Linet, Martha S.

    2008-01-01

    Full text: The effect of low to moderate diagnostic radiation exposures is a topic of interest currently in radiation protection and medicine. Most epidemiological studies, however, lack accurate information on doses received by individuals from medical diagnostic examinations. The need for a better assessment of doses from different types of radiographic examination, especially in the past is crucial for retrospective studies involving medical irradiation. The objective of the present study was to collect and review historic literature discussing radiation dose to the breast likely received from mammography as a function of year. Relevant publications related to mammography for time periods in the 20th century were collected and reviewed for data pertaining to doses to the breast. In many publications, dose to the breasts was not provided. However, it could be estimated in many cases from the dosimetric quantities reported, such as entrance surface dose, either by using provided technical parameters (kV, mAs, filtration) or by assuming typical values. The average value of dose to the breast was derived for each publication. Quality coefficients were derived to assign a greater weight to the most detailed and informative publications. From the dose data and the quality coefficients, a weighted average, minimum and maximum, by time period, were then estimated. Mammography has a long history, from its first use by Salomon in 1913 on 3000 mastectomy specimens to compare x-ray images with tumor lesions. Since then, mammography techniques have evolved in order to obtain better image quality with the objective of improving the diagnosis of breast cancer and other breast diseases. Major technology improvements were seen in the 1970's and 1980's resulting in modifications of medical protocols and consequential reductions of dose to the breast. Dose to the breast from a single view in mammography is presently about 10 times lower than it was in the 1960's when it was about

  19. Class of regular bouncing cosmologies

    Science.gov (United States)

    Vasilić, Milovan

    2017-06-01

    In this paper, I construct a class of everywhere regular geometric sigma models that possess bouncing solutions. Precisely, I show that every bouncing metric can be made a solution of such a model. My previous attempt to do so by employing one scalar field has failed due to the appearance of harmful singularities near the bounce. In this work, I use four scalar fields to construct a class of geometric sigma models which are free of singularities. The models within the class are parametrized by their background geometries. I prove that, whatever background is chosen, the dynamics of its small perturbations is classically stable on the whole time axis. Contrary to what one expects from the structure of the initial Lagrangian, the physics of background fluctuations is found to carry two tensor, two vector, and two scalar degrees of freedom. The graviton mass, which naturally appears in these models, is shown to be several orders of magnitude smaller than its experimental bound. I provide three simple examples to demonstrate how this is done in practice. In particular, I show that graviton mass can be made arbitrarily small.

  20. Tests with films and film-screens using grid-mammography

    International Nuclear Information System (INIS)

    Wolf, G.; Kallinger, G.

    1982-01-01

    A comparison was made between mammography using grid-technique with a film-screen-system and mammography without grid, and with film-screens and also using industrial films. The image-quality of grid mammography looks like the same than using conventional techniques and industrial films. The problem of soft tissue grid techniques lies in the dose requirements, which was more than using film-screen-techniques without grid. New and improved recording systems, which reduce radiation dose when using the grid technique were analyzed. (orig.) [de