Mammography

About: Mammography is a research topic. Over the lifetime, 20643 publications have been published within this topic receiving 513679 citations.

Analysis of mammographic microcalcifications using gray-level image structure features

Abstract: At present, mammography associated with clinical breast examination and breast self-examination is the only effective and viable method for mass breast screening. The presence of microcalcifications is one of the primary signs of breast cancer. It is, difficult however, to distinguish between benign and malignant microcalcifications associated with breast cancer. Here, the authors define a set of image structure features for classification of malignancy. Two categories of correlated gray-level image structure features are defined for classification of "difficult-to-diagnose" cases. The first category of features includes second-order histogram statistics-based features representing the global texture and the wavelet decomposition-based features representing the local texture of the microcalcification area of interest. The second category of features represents the first-order gray-level histogram-based statistics of the segmented microcalcification regions and the size, number, and distance features of the segmented microcalcification cluster. Various features in each category were correlated with the biopsy examination results of 191 "difficult-to-diagnose" cases for selection of the best set of features representing the complete gray-level image structure information. The selection of the best features was performed using the multivariate cluster analysis as well as a genetic algorithm (GA)-based search method. The selected features were used for classification using backpropagation neural network and parameteric statistical classifiers. Receiver operating characteristic (ROC) analysis was performed to compare the neural network-based classification with linear and k-nearest neighbor (KNN) classifiers. The neural network classifier yielded better results using the combined set of features selected through the GA-based search method for classification of "difficult-to-diagnose" microcalcifications.

Breast Cancer Risk by Breast Density, Menopause, and Postmenopausal Hormone Therapy Use

Abstract: Purpose We determined whether the association between breast density and breast cancer risk and cancer severity differs according to menopausal status and postmenopausal hormone therapy (HT) use. Methods We collected data on 587,369 women who underwent 1,349,027 screening mammography examinations; 14,090 women were diagnosed with breast cancer. We calculated 5-year breast cancer risk from a survival model for subgroups of women classified by their Breast Imaging Reporting and Data System (BIRADS) breast density, age, menopausal status, and current HT use, assuming a body mass index of 25 kg/m2. Odds of advanced (ie, IIb, III, IV) versus early (ie, I, IIa) stage invasive cancer was calculated according to BIRADS density. Results Breast cancer risk was low among women with low density (BIRADS-1): women age 55 to 59 years, 5-year risk was 0.8% (95% CI, 0.6 to 0.9%) for non-HT users and 0.9% (95% CI, 0.7% to 1.1%) for estrogen and estrogen plus progestin users. Breast cancer risk was high among women with ver...

Case-control study of factors associated with failure to detect breast cancer by mammography.

Abstract: BACKGROUND Although mammography is widely used to detect breast cancer, it is recognized that not all cancers can be seen on mammographic images. PURPOSE Our purpose was to examine factors associated with failure to detect breast cancer by mammography. METHODS A case-control study was carried out in which subjects in whom histologically verified breast cancer was not detected by mammography (false negatives) were contrasted with subjects in whom breast cancer had been detected by mammography (true positives). Mammograms from individuals with histologically confirmed breast cancer were classified independently by two radiologists who were unaware of the clinical or other characteristics of the subjects. Histologic slides of all tumors were reviewed by one pathologist. RESULTS Three variables were found to be independently and significantly associated with failure to detect breast cancer by mammography. Breast cancer was less likely to be detected by mammography in the presence of extensive parenchymal densities (odds ratio [OR] = 9; 95% confidence interval [CI] = 1.8-44.3), a tumor of lobular histology (OR = 7; 95% CI = 2.2-22.1), and tumors of small size (OR = 0.10; 95% CI = 0.0-0.9). CONCLUSION Our results indicate that biologic factors are associated with failure to detect some breast cancers by mammography and indicate directions for future research in breast imaging.

Late-Stage Breast Cancer Diagnosis and Health Care Access in Illinois.

Abstract: The variations of breast cancer mortality rates from place to place reflect both underlying differences in breast cancer prevalence and differences in diagnosis and treatment that affect the risk of death. This article examines the role of access to health care in explaining the variation of late-stage diagnosis of breast cancer. We use cancer registry data for the state of Illinois by zip code to investigate spatial variation in late diagnosis. Geographic information systems and spatial analysis methods are used to create detailed measures of spatial access to health care such as convenience of visiting primary care physicians and travel time from the nearest mammography facility. The effects of spatial access, in combination with the influences of socioeconomic factors, on late-stage breast cancer diagnosis are assessed using statistical methods. The results suggest that for breast cancer, poor geographical access to primary health care significantly increases the risk of late diagnosis for persons living outside the city of Chicago. Disadvantaged population groups including those with low income and racial and ethnic minorities tend to experience high rates of late diagnosis. In Illinois, poor spatial access to primary health care is more strongly associated with late diagnosis than is spatial access to mammography. This suggests the importance of primary care physicians as gatekeepers in early breast cancer detection.

Prone scintimammography in patients with suspicion of carcinoma of the breast

Abstract: Mammography and physical examination have a sensitivity of 85 percent for detection of carcinoma of the breast. Mammography also has a positive predictive value of 15 to 30 percent. The aim of this study was to evaluate the usefulness of scintimammography (SMM) as a screening technique for the detection of carcinoma of the breast and compare the test's sensitivity and specificity with that of mammography. We conducted SMM on 59 female patients in whom abnormal mammogram and physical examination warranted biopsy of the breast or fine needle aspiration cytology of the breast, or both. Each patient received 20 millicuries of 99mTc Sestamibi intravenously. Five and sixty minutes postinjection, planar breast images in lateral and posterior oblique views were obtained. In 23 patients with biopsy-confirmed carcinoma of the breast, the SMM result was positive. In 33 patients with benign breast lesions, no increased uptake of Sestamibi was noted in the breast. Five other patients with benign lesions of the breast had false-positive scans. There was one patient with an intraductal carcinoma and a cluster of microcalcifications on mammography without an associated mass, for whom the 99mTc Sestamibi scan was negative. In the group of patients studied, the sensitivity of SMM was 95.8 percent, specificity was 86.8 percent, positive predictive value was 82.1 percent and, most importantly, the negative predictive value for the detection of carcinoma of the breast was 97.1 percent. We conclude in this pilot study that SMM is a highly sensitive test that improves the specificity of conventional mammography for the detection of carcinoma of the breast and deserves further study as a screening technique to potentially reduce the number of mammographically "indicated" biopsies of the breast that yield negative results for carcinoma.