Subjectively, tomosynthesis has comparable or superior image quality to that of film-screen mammography in the diagnostic setting, and it has the potential to decrease the recall rate when used adjunctively with digital screening mammography.

No abstract

The authors describe what is, to the best of their knowledge, the first quantitative hemoglobin concentration images of the female breast that were formed with model-based reconstruction of near-infrared intensity-modulated tomographic data. The results in 11 patients, including two with breast tumors with pathologic correlation, are summarized. Hemoglobin concentration appears to correlate with tumor vascularity without the need for exogenous contrast material and thereby has intrinsic diagnostic value.

Purpose:To compare radiologists' diagnostic accuracy and recall rates for breast tomosynthesis combined with digital mammography versus digital mammography alone. Materials and Methods:Institutional review board approval was obtained at each accruing institution. Participating women gave written informed consent. Mediolateral oblique and craniocaudal digital mammographic and tomosynthesis images of both breasts were obtained from 1192 subjects. Two enriched reader studies were performed to compare digital mammography with tomosynthesis against digital mammography alone. Study 1 comprised 312 cases (48 cancer cases) with images read by 12 radiologists; study 2, 312 cases (51 cancer cases) with 15 radiologists. Study 1 readers recorded only that an abnormality requiring recall was present; study 2 readers had additional training and recorded both lesion type and location. Diagnostic accuracy was compared with receiver operating characteristic analysis. Recall rates of noncancer cases, sensitivity, specificity, and positive and negative predictive values determined by analyzing Breast Imaging Reporting and Data System scores were compared for the two methods. Results:Diagnostic accuracy for combined tomosynthesis and digital mammography was superior to that of digital mammography alone. Average difference in area under the curve in study 1 was 7.2% (95% confidence interval [CI]: 3.7%, 10.8%; P , .001) and in study 2 was 6.8% (95% CI: 4.1%, 9.5%; P , .001). All 27 radiologists increased diagnostic accuracy with addition of tomosynthesis. Recall rates for noncancer cases for all readers significantly decreased with addition of tomosynthesis (range, 6%-67%; P , .001 for 25 readers, P , .03 for all readers). Increased sensitivity was largest for invasive cancers: 15% and 22% in studies 1 and 2 versus 3% for in situ cancers in both studies. Conclusion:Addition of tomosynthesis to digital mammography offers the dual benefit of significantly increased diagnostic accuracy and significantly reduced recall rates for noncancer cases.q RSNA, 2012 Supplemental material: http://radiology.rsna.org/lookup /suppl

Near-infrared spectroscopic tomography was used to measure the properties of 24 mammographically normal breasts to quantify whole-breast absorption and scattering spectra and to evaluate which tissue composition characteristics can be determined from these spectra. The absorption spectrum of breast tissue allows quantification of (i) total hemoglobin concentration, (ii) hemoglobin oxygen saturation, and (iii) water concentration, whereas the scattering spectrum provides information about the size and number density of cellular components and structural matrix elements. These property data were tested for correlation to demographic information, including subject age, body mass index, breast size, and radiographic density. Total hemoglobin concentration correlated inversely to body mass index, likely because lower body mass indicates proportionately less fat and more glandular tissue, and glandular tissue contains greater vascularity, hence, more total hemoglobin. Optical scattering was correlated to breast diameter, subject age, and radiographic density. In the radiographic density, fatty breasts had low scattering power and extremely dense breasts had higher values. This observation is consistent with low attenuation of conventional x-rays with fat and higher attenuation in glandular tissues. Optically, fatty tissues have large scatterers leading to a low scattering power, whereas glandular or fibrous tissues have more cellular and collagen-based structures that lead to high scattering power. The study presents correlative data supporting the hypothesis that optical measurements of absorption and scattering can provide physiologically relevant information about breast tissue composition. These breast constituents vary significantly between individuals and can be altered because of changes in breast physiology or pathological state.T he breast is a highly heterogeneous and dynamically complex organ whose characteristics depend on factors such as age, hormonal status, habitus, family and medical history, and genetics (1-3). Normal breast tissue changes considerably during development, pregnancy, and menopause, and throughout the menstrual cycle. It has been documented that blood flow can increase up to 50% at the time of ovulation; and by the end of the monthly cycle, some women may undergo breast enlargement of up to 20% because of increased vascularity and water content (1). Total blood content can vary up to a factor of 5 or more between women based on their body-fat content, making the breast one of the most physiologically variable tissues in the human body. With nearinfrared (NIR) spectral imaging, hemoglobin concentration, oxygen saturation, and water content can yield information about the current physiological state of the normal breast.The relatively good transparency of tissue in the red and NIR spectrum (i.e., 600-1,000 nm) permits sufficient light penetration to detect signals through as much as a dozen centimeters of the breast. In the NIR spectrum, the primary absorbers of light are hemoglobin, oxyh...

Results from EM breast examinations provide statistical evidence of a mean increase in image contrast of 150%-200% between abnormal (benign and malignant) and normal breast tissue.

We have developed a microwave tomography system for experimental breast imaging. In this paper we illustrate a strategy for optimizing the coupling liquid for the antenna array based on in vivo measurement data. We present representative phantom experiments to illustrate the imaging system's ability to recover accurate property distributions over the range of dielectric properties expected to be encountered clinically. To demonstrate clinical feasibility and assess the microwave properties of the normal breast in vivo, we summarize our initial experience with microwave breast exams of 43 women categorized as BIRADS 1. The clinical results show a high degree of bilateral symmetry in the whole breast average microwave properties. Focal assessments of microwave properties are associated with breast tissue composition evaluated through radiographic density categorization verified through MR image correlation in selected cases. Specifically, both whole breast average and local microwave properties increase with increasing radiographic density where the latter exhibits a more substantial rise. These findings support our hypothesis that water content variations in the breast play an influential role in dictating the overall dielectric property distributions and indicate that the microwave properties in the breast are more heterogeneous than previously believed based on ex vivo property measurements reported in the literature.

Magnetic resonance (MR)-guided near-infrared spectral tomography was developed and used to image adipose and fibroglandular breast tissue of 11 normal female subjects, recruited under an institutional review board-approved protocol. Images of hemoglobin, oxygen saturation, water fraction, and subcellular scattering were reconstructed and show that fibroglandular fractions of both blood and water are higher than in adipose tissue. Variation in adipose and fibroglandular tissue composition between individuals was not significantly different across the scattered and dense breast categories. Combined MR and near-infrared tomography provides fundamental molecular information about these tissue types with resolution governed by MR T1 images.hemoglobin ͉ magnetic resonance imaging ͉ water ͉ fat ͉ oxygen saturation