Showing papers on "Mammography published in 1998"

Ten-year risk of false positive screening mammograms and clinical breast examinations.

Abstract: Background The cumulative risk of a false positive result of a breast-cancer screening test is unknown. Methods We performed a 10-year retrospective cohort study of breast-cancer screening and diagnostic evaluations among 2400 women who were 40 to 69 years old at study entry. Mammograms or clinical breast examinations that were interpreted as indeterminate, aroused a suspicion of cancer, or prompted recommendations for additional workup in women in whom breast cancer was not diagnosed within the next year were considered to be false positive tests. Results A total of 9762 screening mammograms and 10,905 screening clinical breast examinations were performed, for a median of 4 mammograms and 5 clinical breast examinations per woman over the 10-year period. Of the women who were screened, 23.8 percent had at least one false positive mammogram, 13.4 percent had at least one false positive breast examination, and 31.7 percent had at least one false positive result for either test. The estimated cumulative risk...

Effects of age, breast density, ethnicity, and estrogen replacement therapy on screening mammographic sensitivity and cancer stage at diagnosis: review of 183,134 screening mammograms in Albuquerque, New Mexico.

Abstract: PURPOSE: To examine how common patient factors affect screening mammographic sensitivity and cancer stage at diagnosis. MATERIALS AND METHODS: The authors used a population-based database of 183,134 screening mammograms and a statewide tumor registry to identify 807 breast cancers detected at screening mammography. RESULTS: Sensitivity varied significantly with ethnicity, use of estrogen replacement therapy, mammographic breast density, and age. Sensitivity was 54% (13 of 24) in women younger than 40 years, 77% (121 of 157) in women aged 40-49 years, 78% (224 of 286) in women aged 50-64 years, and 81% (277 of 340) in women older than 64 years. Sensitivity was 68% (162 of 237) for dense breasts and 85% (302 of 356) for nondense breasts and 74% (180 of 244) in estrogen replacement therapy users and 81% (417 of 513) in nonusers. Sensitivity was most markedly reduced with the combination of dense breasts and estrogen replacement therapy use; there was little difference when only one factor was present. Median...

The false-negative mammogram.

Abstract: In general, failure to detect or correctly characterize breast cancer can be attributed to one of four main factors: inherent limitations of screen-film mammography, inadequate radiographic technique, subtle or unusual lesion characteristics, and interpretation error. The restricted latitude and display contrast of screen-film mammography are among the significant factors that result in decreased visualization of breast tumors and microcalcifications in patients with dense fibroglandular tissue. Unlike the inherent limitations of screen-film mammography, a poor radiographic technique can be improved on and should be eliminated. Crucial components of a well-performed mammographic examination are correct positioning, adequate compression, and proper image exposure. Lesion characteristics that may lead to a false-negative mammogram include small size, a site where visualization is difficult, visualization on only one view, a benign or probably benign appearance, lack of a desmoplastic reaction, and slow or no apparent growth. Causes of interpretation error include suboptimal viewing conditions, outside distractions, lack of a systematic approach, oversight of a subtle lesion because of an obvious finding, lack of knowledge of clinical findings, imprecise correlation with results of other studies, and nonbelief. Recognition of these various factors should help decrease the rate of false-negative mammograms.

Variability and Accuracy in Mammographic Interpretation Using the American College of Radiology Breast Imaging Reporting and Data System

Abstract: Background: Several studies, which were limited by their small sample size and selection of difficult cases for review, have reported substantial variability among radiologists in interpretation of mammographic examinations. We have determined, in the largest study to date, intraobserver and interobserver agreement in interpreting screening mammography and accuracy of mammography by use of the American College of Radiology Breast Imaging Reporting and Data System (BI-RADS). Methods: The mammographic examinations were randomly selected on the basis of original mammographic interpretation and cancer outcome from 71 713 screening examinations performed by the Mobile Mammography Screening Program of the University of California, San Francisco, during the period from April 1985 through February 1995. The final sample included 786 abnormal examinations with no cancer detected, 267 abnormal examinations with cancer detected, and 1563 normal examinations. Films were read separately by two radiologists according to BI-RADS. Cancer status was determined by contacting women’s physicians and by linkage to the regional Surveillance, Epidemiology, and End Results Program. Results: There was moderate agreement between radiologists in reporting the presence of a finding when cancer was present (k = 0.54) and substantial agreement when cancer was not present (k = 0.62). Agreement was moderate in assigning one of the five assessment categories but was statistically significantly lower when cancer was present relative to when cancer was not present (k = 0.46 versus 0.56; two-sided P = .02). Agreement for reporting the presence of a finding and mammographic assessment was twofold more likely for examinations with less dense breasts. Agreement was higher on repeat readings by the same radiologists than between radiologists. The sensitivity of mammography was lower with BI-RADS than with the original system for mammographic interpretation, but the positive predictive value of mammography was higher. Conclusion: Considerable variability in interpretation of mammographic examinations exists; this variability and the accuracy of mammography are neither improved nor diminished with use of BI-RADS. [J Natl Cancer Inst 1998;90: 1801‐9]

Assessment of the Size, Position, and Optical Properties of Breast Tumors in Vivo by Noninvasive Optical Methods

Abstract: We present a method for the noninvasive determination of the size, position, and optical properties ~absorption and reduced scattering coefficients! of tumors in the human breast. The tumor is first detected by frequency-domain optical mammography. It is then sized, located, and optically characterized by use of diffusion theory as a model for the propagation of near-infrared light in breast tissue. Our method assumes that the tumor is a spherical inhomogeneity embedded in an otherwise homogeneous tissue. We report the results obtained on a 55-year-old patient with a papillary cancer in the right breast. We found that the tumor absorbs and scatters near-infrared light more strongly than the surrounding healthy tissue. Our method has yielded a tumor diameter of 2.1 6 0.2 cm, which is comparable with the actual size of 1.6 cm, determined after surgery. From the tumor absorption coefficients at two wavelengths ~690 and 825 nm!, we calculated the total hemoglobin concentration ~40 6 10 mM! and saturation ~71 6 9%! of the tumor. These results can provide the clinical examiner with more detailed information about breast lesions detected by frequency-domain optical mammography, thereby enhancing its potential for specificity. © 1998 Optical Society of America OCIS codes: 170.3830, 300.0300, 300.1030, 290.0290.

Analysis of mammographic density and breast cancer risk from digitized mammograms.

Abstract: To evaluate the association between mammographic density and breast cancer risk, a simple, observer-assisted technique called interactive thresholding was developed that allows reliable quantitative assessment of mammographic density with use of a computer workstation. Use of this technique helps confirm that mammographic density is one of the strongest risk factors for breast cancer and is present in a large proportion of breast cancer cases. The strong relationship between mammographic density and breast cancer risk suggests that the causes of breast cancer may be better understood by identifying the factors associated with mammographically dense tissue and determining how such tissue changes as these factors vary. Furthermore, because it can be modified, mammographic density may also be a good vehicle for the development and monitoring of potential preventive strategies. Areas of ongoing investigation include evaluating a potential genetic component of mammographic density by comparing density measurements in twins and understanding changes in density relative to age, menopausal status, exogenous hormone use, and exposure to environmental carcinogens. In addition, work is ongoing to establish measurements from imaging modalities other than mammography and to relate these measurements directly to breast cancer risk.

Breast cancer screening programmes in 22 countries: current policies, administration and guidelines

Abstract: The finding that mammography with or without clinical breast examination can reduce breast cancer mortality by 25-30% has prompted several countries to introduce routine screening on a population basis. The International Breast Cancer Screening Network (IBSN) conducted surveys in 1990 and 1995 to yield international data on the policies funding and administration of national regional or pilot population-based screening programs. Comparison of the results of the two surveys revealed several changes from 1990 to 1995. The number of countries (primarily European) that have established or plan to launch breast cancer screening programs increased from 9 to 22. There has been a trend toward raising the lower age limit for mammography screening from 40 to 50 years with a 2-year interval between screenings. Also noted was more widespread use of the clinical breast examination and breast self-examination as additional detection methods. Countries with centralized systems for policy funding and administration were more likely to have achieved complete population coverage than those with decentralized systems. The IBSN is shifting its focus from generating an international database to developing methodologies for the evaluation of mammography screening outcomes.

Low-dose phase contrast x-ray medical imaging

Abstract: Phase contrast x-ray imaging is a powerful technique for the detection of low-contrast details in weakly absorbing objects. This method is of possible relevance in the field of diagnostic radiology. In fact, imaging low-contrast details within soft tissue does not give satisfactory results in conventional x-ray absorption radiology, mammography being a typical example. Nevertheless, up to now all applications of the phase contrast technique, carried out on thin samples, have required radiation doses substantially higher than those delivered in conventional radiological examinations. To demonstrate the applicability of the method to mammography we produced phase contrast images of objects a few centimetres thick while delivering radiation doses lower than or comparable to doses needed in standard mammographic examinations (typically mean glandular dose (MGD)). We show images of a custom mammographic phantom and of two specimens of human breast tissue obtained at the SYRMEP bending magnet beamline at Elettra, the Trieste synchrotron radiation facility. The introduction of an intensifier screen enabled us to obtain phase contrast images of these thick samples with radiation doses comparable to those used in mammography. Low absorbing details such as thick nylon wires or thin calcium deposits within breast tissue, invisible with conventional techniques, are detected by means of the proposed method. We also find that the use of a bending magnet radiation source relaxes the previously reported requirements on source size for phase contrast imaging. Finally, the consistency of the results has been checked by theoretical simulations carried out for the purposes of this experiment.

A novel approach to microcalcification detection using fuzzy logic technique

Abstract: Breast cancer continues to be a significant public health problem in the United States. Approximately, 182,000 new cases of breast cancer are diagnosed and 46,000 women die of breast cancer each year. Even more disturbing is the fact that one out of eight women in the United States will develop breast cancer at some point during her lifetime. Since the cause of breast cancer remains unknown, primary prevention becomes impossible. Computer-aided mammography is an important and challenging task in automated diagnosis. It has great potential over traditional interpretation of film-screen mammography in terms of efficiency and accuracy. Microcalcifications are the earliest sign of breast carcinomas and their detection is one of the key issues for breast cancer control. In this study, a novel approach to microcalcification detection based on fuzzy logic technique is presented. Microcalcifications are first enhanced based on their brightness and nonuniformity. Then, the irrelevant breast structures are excluded by a curve detector. Finally, microcalcifications are located using an iterative threshold selection method. The shapes of microcalcifications are reconstructed and the isolated pixels are removed by employing the mathematical morphology technique. The essential idea of the proposed approach is to apply a fuzzified image of a mammogram to locate the suspicious regions and to interact the fuzzified image with the original image to preserve fidelity. The major advantage of the proposed method is its ability to detect microcalcifications even in very dense breast mammograms. A series of clinical mammograms are employed to test the proposed algorithm and the performance is evaluated by the free-response receiver operating characteristic curve. The experiments aptly show that the microcalcifications can be accurately detected even in very dense mammograms using the proposed approach.

Computerized analysis of breast lesions in three dimensions using dynamic magnetic-resonance imaging

Abstract: Contrast-enhanced magnetic resonance imaging (MRI) of the breast is known to reveal breast cancer with higher sensitivity than mammography alone. The specificity is, however, compromised by the observation that several benign masses take up contrast agent in addition to malignant lesions. The aim of this study is to increase the objectivity of breast cancer diagnosis in contrast-enhanced MRI by developing automated methods for computer-aided diagnosis. Our database consists of 27 MR studies from 27 patients. In each study, at least four MR series of both breasts are obtained using FLASH three-dimensional (3D) acquisition at 90 s time intervals after injection of Gadopentetate dimeglumine (Gd-DTPA) contrast agent. Each series consists of 64 coronal slices with a typical thickness of 2 mm, and a pixel size of 1.25 mm. The study contains 13 benign and 15 malignant lesions from which features are automatically extracted in 3D. These features include margin descriptors and radial gradient analysis as a function of time and space. Stepwise multiple regression is employed to obtain an effective subset of combined features. A final estimate of likelihood of malignancy is determined by linear discriminant analysis, and the performance of classification by round-robin testing and receiver operating characteristics (ROC) analysis. To assess the efficacy of 3D analysis, the study is repeated in two-dimensions (2D) using a representative slice through the middle of the lesion. In 2D and in 3D, radial gradient analysis and analysis of margin sharpness were found to be an effective combination to distinguish between benign and malignant masses (resulting area under the ROC curve: 0.96). Feature analysis in 3D was found to result in higher performance of lesion characterization than 2D feature analysis for the majority of single and combined features. In conclusion, automated feature extraction and classification has the potential to complement the interpretation of radiologists in an objective, consistent, and accurate way.

Variation in Mammographic Breast Density by Time in Menstrual Cycle Among Women Aged 40–49 Years

Abstract: Background: Mammography is less effective for women aged 40‐49 years than for older women, which has led to a call for research to improve the performance of screening mammography for younger women One factor that may influence the performance of mammography i s b reast d ensity Younger women have greater mammographic breast density on average, and increased breast density increases the likelihood of false-negative and falsepositive mammograms We investigated whether breast density varies according to time in a woman’s menstrual cycle Methods: Premenopausal women aged 40‐49 years who were not on exogenous hormones and who had a screening mammogram at a large health maintenance organization during 1996 were studied (n = 2591) Time in the menstrual cycle was based on the woman’s self-reported last menstrual bleeding and usual cycle length Results: A smaller proportion of women had ‘‘extremely dense’’ breasts during the follicular phase of their menstrual cycle (24% for week 1 and 23% for week 2) than during the luteal phase (28% for both weeks 3 and 4) (twosided P = 04 for the difference in breast density between the phases, adjusted for body mass index) The relationship was stronger for women whose body mass index was less than or equal to the median ( two-sided P <01), t he group who have the greatest breast density Conclusions/Implications: These findings are consistent with previous evidence suggesting that scheduling a woman’s mammogram during the follicular phase (first and second week) of her menstrual cycle instead of during the luteal phase (third and fourth week) may improve the accuracy of mammography for premenopausal women in their forties Breast tissue is less radiographically dense in the follicular phase than in the luteal phase [J Natl Cancer Inst 1998;90:906‐10]

Mammography use helps to explain differences in breast cancer stage at diagnosis between older black and white women.

Abstract: Background: Older black women are less likely to undergo mammography and are more often given a diagnosis of advanced-stage breast cancer than older white women. Objective: To investigate the exten...

Factors associated with women's adherence to mammography screening guidelines.

Abstract: OBJECTIVE: To examine individual and environmental factors associated with adherence to mammography screening guidelines. DATA SOURCES: A unique data set that combines a national probability sample (1992 National Health Interview Survey); a national probability sample of mammography facility characteristics (1992 National Survey of Mammography Facilities); county-level data on 1990 HMO market share; and county-level data on the supply of primary care providers (1991 Area Resource File). STUDY DESIGN: The design was cross-sectional. DATA EXTRACTION/ANALYSIS: Data sets were linked to create an individual-level sample of women ages 50-74 (weighted n = 2,026). We used multipart, sequential logistic regression models to examine the predictors of having ever had mammography, having had recent mammography, and adherence to guidelines. We categorized women as adherent if they reported a lifetime number of exams appropriate for their age (based on screening every two years) and they reported having had an exam in the past two years. PRINCIPAL FINDINGS: Only 27 percent of women had the age-appropriate number of screening exams (range 16 percent-37 percent), while 59 percent of women had been screened within two years. Women were significantly more likely to adhere to screening guidelines if they reported participating with their doctor in the decision to be screened; were younger; had smaller families, higher education and income, and a recent Pap smear; reported breast problems; and lived in an area with a higher percentage of mammography facilities with reminder systems, no shortage of primary care providers, higher HMO market share, and higher screening charges. CONCLUSIONS: A small percentage of women adhere to screening guidelines, suggesting that adherence needs to become a focus of clinical, programmatic, and policy efforts.

The growth law of primary breast cancer as inferred from mammography screening trials data.

Abstract: Despite considerable progress in understanding tumour development, the law of growth for human tumours is still a matter of some dispute. In this study, we used large-scale mammography screening trial data to deduce the growth law of primary breast cancer. We compared the empirical tumour population size distributions of primary breast cancer inferred from these data to the distributions that correspond to various possible theoretical growth functions. From this, we showed that the data are inconsistent with the exponential, logistic and Gompertz laws, but support power law growth (exponent approximately 0.5). This law indicates unbounded growth but with slowing mass-specific growth rate and doubling time. In the clinical size ranges, it implies a greater decline in the mass-specific growth rate than would be predicted by the Gompertz law using the accepted parameters. This suggests that large tumours would be less sensitive to cycle-specific therapies, and be better treated first by non-cell cycle-specific agents. We discussed the use of our study to estimate the sensitivity of mammography for the detection of small tumours. For example, we estimated that mammography is about 30% less sensitive in the detection of tumours in the 1 to 1.5-cm range than it is in detecting larger tumours.

Mammographic densities and breast cancer risk

Abstract: Variations between individuals in the radiographic appearance, or mammographic pattern, of the female breast arise because of differences in the relative amounts and X-ray attenuation characteristics of fat and connective and epithelial tissue. Studies using quantitative methods of assessment have consistently shown these variations to be strongly related to risk of breast cancer. Individuals with extensive areas of radiologically dense breast tissue on the mammogram have been found to have a risk of breast cancer that is four to six times higher than women with little or no density. In this paper, we propose a model for the relationship of mammographic densities to risk of breast cancer. We propose that the risk of breast cancer associated with mammographically dense breast tissue is due to the combined effects of two processes: cell proliferation (mitogenesis), induced by growth factors and sex hormones and influenced by reproductive risk factors for breast cancer; and damage to the DNA of dividing cells (mutagenesis) by mutagens generated by lipid peroxidation. We review the evidence that each of these processes is associated with mammographic densities and propose further work that we believe should be done to clarify these relationships.

Infrared Imaging of the Breast: Initial Reappraisal Using High-Resolution Digital Technology in 100 Successive Cases of Stage I and II Breast Cancer

Abstract: There is a general consensus that earlier detection of breast cancer should result in improved survival. Current breast imaging relies primarily on mammography. Despite better equipment and regulation, variability in interpretation and tisuue density still affect acuragy. A number of adjuvant imaging techniques are currently being used, including doppler ultrasound and gadolinium-enhanced MRI, which can detect cancer-induced neovascularity. In order to assess the potential contribution of currently available high-resolution digital infrared technology capable of recognizing minute regional vascular flow related temperature variation, we retrospectively reviewed the relative ability of our preoperative clinical exam, mammography, and infrared imaging to detect 100 new cases of ductal carcinoma in situ, stage I and II breast cancer. While the false-negative rate of infrared imaging was 17%, at least one abnormal infrared sign was detected in the remaining 83 cases, including 10 of the 15 patients, a slightly younger cohort, who had nonspecific mammograms. The 85% sensitivity rate of mamography alone thus increased to 95% when combining both imaging modalities. Access to infrared information was also pertinent when confronted with the relatively frequent contributory but equivocal clinical exam (34%) and mammography (19%). The average size of those tumors undetected by mammography or infrared mamography was 1.66 cm and 1.28 cm, respectively, while the false- positive rate of infrared imaging in concurrent series of 100 successive benign open breast biopsies was 19%. Our initial experience would suggest that, when done concomitantly with clinical exam and mammography, high-resolution digital infrared imaging can provide additional safe, practical, and objective information. Further evaluation, preferably in controlled prospective multicenter trials, would provide valuable data.

Scintimammography with technetium-99m methoxyisobutylisonitrile: Results of a prospective European multicentre trial

Abstract: The aim of the trial was to determine the diagnostic accuracy of scintimmammography with technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) in the detection of primary breast cancer and to verify its clinical usefulness. A total of 246 patients with a suspicious breast mass or positive mammogram were included in this prospective European multicentre trial. At 5 min and 60 min (optional) p.i. two lateral prone images were acquired for 10 min each; 30 min p.i. one anterior image was acquired for 10 min. There were 253 lesions (195 palpable and 58 non-palpable), in respect of which histology revealed 165 cancers and 88 benign lesions. Institutional and blinded read results were correlated to core laboratory histopathology results obtained during excisional biopsy. Diagnostic accuracy for the detection of breast cancer was calculated per lesion. The overall sensitivity and specificity of blinded read scintimammography were 71% and 69%, respectively. For palpable lesions, the sensitivity of blinded read and institutional read scintimammography was 83% and 91%, respectively. Sensitivity was not dependent on the density of the breast tissue. Invasive ductal and invasive lobular cancers showed similar sensitivity. The sensitivity and specificity of mammography were 91% and 42%, respectively, and did not depend on the tumour size. In 60% of false-negative mammograms, 99mTc-MIBI was able to diagnose malignancy (true-positive). High-quality imaging with 99mTc-MIBI has a high diagnostic accuracy for the detection of primary breast cancer. Used as a complementary method, scintimammography with 99mTc-MIBI can help to diagnose breast cancer at an earlier stage in patients with dense breasts.

A comparison of cancer detection rates achieved by breast cancer screening programmes by number of readers, for one and two view mammography: results from the UK National Health Service breast screening programme

Abstract: Objective To determine the increased cancer detection rate, if any, of programmes in the UK National Health Service breast screening programme (NHSBSP) using more than single reading of mammograms.Design Information on the detection of cancers by individual screening programmes from annual (KC62) returns, supplemented by questionnaire information about the number of readers.Setting The 87 NHSBSP programmes from England and Wales for the screening year 1 April 1996 to 31 March 1997. The study includes all programmes for prevalent screens where two views are mandatory, but excludes the four programmes using two view mammography for incident screening. Main outcome measuresCancer detection, invasive cancer detection, and small (<15 mm) invasive cancer detection by mammographic reading protocol using single reading as the reference level.Results Programmes collectively using single reading detected the lowest rate of cancers at both prevalent (first) and incident (subsequent) screening. The highest rate of ag...

The relationship of anthropometric measures to radiological features of the breast in premenopausal women.

Abstract: We studied 273 premenopausal women recruited from mammography units who had different degrees of density of the breast parenchyma on mammography, in whom we measured height, weight and skinfold thicknesses. Mammograms were digitized to high spatial resolution by a scanning densitometer and images analysed to measure the area of dense tissue and the total area of the breast. Per cent density and the area of non-dense tissue were calculated from these measurements. We found that the mammographic measures had different associations with body size. Weight and the Quetelet index of obesity were strongly and positively associated with the area of non-dense tissue and with the total area of the breast, but less strongly and negatively correlated with the area of dense tissue. We also found a strong inverse relationship between the areas of radiologically dense and non-dense breast tissue. Statistical models containing anthropometric variables explained up to 8% of the variance in dense area, but explained up to 49% of the variance in non-dense area and 43% of variance in total area. These results suggest that aetiological studies in breast cancer that use mammographic density should consider dense and non-dense tissues separately. In addition to per cent density, methods should be examined that combine information from these two tissues.

Metaplastic carcinoma of the breast: report of three cases.

Abstract: BACKGROUND Metaplastic carcinoma is a rare form of breast carcinoma that often is confused with other benign and malignant entities. The diagnosis can be difficult to establish on both a clinical and conventional histopathologic basis. One report recently described clinical and mammographic features dissimilar to the authors' experience but to the authors' knowledge no other reports have been published. Therefore a review of three cases was undertaken; all patients had undergone mammography to identify and report the mammographic features of this disease, suggesting that imaging may add to the proper diagnosis of this entity. METHODS Three clinical cases in which the diagnosis of metaplastic carcinoma was confirmed and for which mammography was performed were reviewed retrospectively. Follow-up on all three patients was available. RESULTS Metaplastic carcinoma may be manifest as a well circumscribed mass or an irregular or spiculated mass. The latter always is highly suspicious for malignancy and the former incurs suspicion if it grows, although in this series the smooth mass was biopsied immediately. The spiculated masses were associated with delayed diagnosis and poorer prognosis because immunohistochemical studies were not performed on the original excisional biopsy specimens. CONCLUSIONS Although spiculated masses usually are associated with invasive ductal and lobular carcinoma, they also may represent metaplastic carcinoma and immunohistochemical studies often are required to establish this diagnosis and avoid delay in proper treatment. Well circumscribed masses representing this disease may suggest benign disease but metaplastic carcinoma should be included in the differential diagnosis, especially if the mass enlarges. Cancer 1998;82:1082-7. © 1998 American Cancer Society.

The National Breast and Cervical Cancer Early Detection Program: report on the first 4 years of mammography provided to medically underserved women.

Abstract: We describe results from 284,503 mammographic examinations and associated diagnostic workups provided to medically underserved women in an ongoing nationwide breast cancer early detection program.We report the results of mammographic examinations and diagnostic workups on 230,143 medically underserved women 40 years old or older who underwent at least one mammographic examination from July 1991 through June 1995. Mammograms were obtained in hundreds of mammography and clinical facilities throughout the United States, including community health centers, health department clinics, private practitioners' offices, university based facilities, and mobile mammography units. Our analysis included rates of mammograms with abnormal findings (reported according to the categories of the American College of Radiology Breast Imaging Reporting and Data System), breast cancer detection rates, numbers of diagnostic procedures performed, stage and size distribution of breast cancers, and positive predictive value of mammo...

Percutaneous removal of malignant mammographic lesions at stereotactic vacuum-assisted biopsy.

Abstract: PURPOSE: To determine whether complete percutaneous removal of a malignant lesion detected at mammography ensures complete excision of the carcinoma histopathologically. MATERIALS AND METHODS: A retrospective review was performed of 135 lesions in which stereotactic biopsy was performed with a directional, vacuum biopsy instrument and an 11-gauge probe followed by mammography. Carcinoma was diagnosed at stereotactic biopsy in 51 (38%) lesions. In 15 (29%) carcinomas, the lesion seen at mammography was removed at stereotactic biopsy. Surgical findings were available for correlation with biopsy and imaging findings in all 15 cases. Mammographic and histopathologic findings were reviewed. RESULTS: Mammographic findings were calcifications in 11 lesions and a mass in four lesions. The median lesion size was 0.7 cm (range, 0.2-1.4 cm), and the median number of biopsy specimens was 15 (range, 10-22 specimens). Histopathologic findings at stereotactic biopsy were ductal carcinoma in situ in 12 lesions and infilt...

Mammographic breast density and risk of breast cancer: masking bias or causality?

Abstract: Masking bias is hypothesized to explain associations between breast density and breast cancer risk. Tumours in dense breasts may be concealed at the initial examination, but manifest themselves in later years, suggesting an increase in breast cancer incidence. We studied the association between breast density and breast cancer risk in 0, 1–2, 3–4 and 5–6 year periods between initial examination and diagnosis. We studied 359 cases and 922 referents, identified in a breast cancer screening programme in Nijmegen, the Netherlands. Breast density was assessed at the initial examination and classified as 'dense' (if > 25% of the breast was composed of density) or 'lucent' (≤ 25% density). In women examined with mid-1970s film screen mammography, we found that at time 0 the odds ratio (OR) for women with dense breasts compared to those with lucent breasts was 1.4 (95% confidence interval (CI): 0.7–6.2). After a 3–4 year period the risk was increased to 3.3 (95% CI: 1.5–7.1). Then, the risk decreased again (OR: 1.2, 95% CI: 0.6–2.7). This rise and decline in risk are in accordance with the masking hypothesis. The observation, however, that the risk at time 0 does not appear to be lower for women with dense breasts than for those with lucent breasts, seems to be inconsistent with the masking hypothesis and may be indicative of causality. The same analysis were performed in women whose initial screening examination was done with current high-quality mammography. Due to the small size of this study group no firm conclusions could be drawn, but it seems as if masking bias could still play a role with high-quality mammography.

Breast lesion localization: a freehand, interactive MR imaging-guided technique.

Abstract: PURPOSE: To evaluate interactive magnetic resonance (MR) imaging-guided preoperative needle localization and hookwire placement in the noncompressed breast in patients in the prone position. MATERIALS AND METHODS: Nineteen MR imaging-guided breast lesion localization procedures were performed in 17 patients aged 38-70 years (mean age, 48 years) by using an open-platform breast coil in either a 1.5-T, closed-bore imager (n = 14) or a 0.5-T, open-bore imager (n = 5). Rapid imaging (fast spin-echo, water-selective fast spin-echo, or water-specific three-point Dixon gradient-echo) was alternated with freehand manipulation of an MR-compatible needle to achieve accurate needle placement. RESULTS: Up to three manipulations of the needle were required during an average of 9 minutes to reach the target lesion. MR imaging findings confirmed the final needle position within 9 mm of the target in all cases. The accuracy of 10 localizations was independently corroborated either at mammography or at ultrasonography. Ni...

MR imaging of mammographically detected clustered microcalcifications: is there any value?

Abstract: PURPOSE: To assess the value of dynamic magnetic resonance (MR) imaging in patients with mammographically detected suspicious microcalcifications. MATERIALS AND METHODS: Sixty-three patients (age range, 31-84 years; mean age, 56 years) with mammographically suspicious clustered microcalcifications underwent dynamic MR imaging of the breast before surgical biopsy. MR imaging was performed with a 1.5-T unit and a two-dimensional fast low-angle shot sequence with a flip angle of 80 degrees. Thirty-two axial sections, 4 mm thick and without interval gaps, were acquired before and five times after administration of gadopentetate dimeglumine (dose, 0.1 mmol per kilogram of bodyweight). Histologic findings were used as the standard of reference. Any effect of MR imaging on surgical management was noted. RESULTS: Biopsy findings verified five patients with T1 invasive carcinomas, 33 with ductal carcinomas in situ, 13 with proliferative fibrocystic disease, eight with nonproliferative fibrocystic disease, and four...