Breast Imaging Technology Research Articles

To Seek Perfection or Not? That Is the Question

The universally accepted definitions of screening and diagnostic for breast imaging examinations are critical to maintain; this allows us to perform valid comparisons of breast imaging technologies and critically assess whether their greatest impact would be in a screening or diagnostic setting or both.

SU-E-I-02: Size-Dependent Computed Tomography Histogram Analysis: Towards Breast Tissue Segmentation.

To examine the effects of object size on scatter-corrected CT histograms to be used in threshold-based tissue segmentation. A polyethylene cone filled with various concentrations of water and methanol mixtures, simulating glandular and adipose tissues, were imaged with our quasi-monochromatic dedicated breast CT, and scatter corrected using beam-stop array measurements. Images were reconstructed using iterative OSC, and individual coronal slices along the central axis of the cone were analyzed, with radii ranging from 3.25-6.25cm. Histograms from each slice were fit with two Gaussians (fluid filling and cone material) using nonlinear least squares methods, and the corresponding standard deviation and peak centroid of each filled material were evaluated as a function of object radius. Identical methods were applied to dedicated breast CT images of four patients for clinical comparison. Analysis of phantoms and breast data indicates low correlation between the standard deviation and object diameter. The centroids of the Gaussian peaks demonstrate an inverse linear relationship with increasing object size, independent of object material. The clinical datasets show a similar linear relationship between centroids and breast radius. Data indicate that using a linear combination of Gaussian distribution functions to segment breast tissue in scatter corrected, quasi-monochromatic cone beam dedicated breast CT is possible. An object size-independent variation of attenuation values may allow for consistent restraints on initial fit parameters, resulting in improved confidence using Gaussian curve fitting. Appropriate scaling of the size-dependent volume slices, or independent slice analysis, is necessary to minimize binning variability for accurate tissue segmentation using Gaussian curve fitting. This work is supported by National Institutes of Health (R01-CA096821) and NIH Training Grant (T32-EB007185). MPT is the inventor of this hybrid breast imaging technology, and is named as an inventor on the patent for this technology assigned to Duke (US Pat. #7,609,808). If this technology becomes commercially successful, MPT and Duke could benefit financially.

A novel breast software phantom for biomechanical modeling of elastography

In developing breast imaging technologies, testing is done with phantoms. Physical phantoms are normally used but their size, shape, composition, and detail cannot be modified readily. These difficulties can be avoided by creating a software breast phantom. Researchers have created software breast phantoms using geometric and/or mathematical methods for applications like image fusion. The authors report a 3D software breast phantom that was built using a mechanical design tool, to investigate the biomechanics of elastography using finite element modeling (FEM). The authors propose this phantom as an intermediate assessment tool for elastography simulation; for use after testing with commonly used phantoms and before clinical testing. The authors design the phantom to be flexible in both, the breast geometry and biomechanical parameters, to make it a useful tool for elastography simulation. The authors develop the 3D software phantom using a mechanical design tool based on illustrations of normal breast anatomy. The software phantom does not use geometric primitives or imaging data. The authors discuss how to create this phantom and how to modify it. The authors demonstrate a typical elastography experiment of applying a static stress to the top surface of the breast just above a simulated tumor and calculate normal strains in 3D and in 2D with plane strain approximations with linear solvers. In particular, they investigate contrast transfer efficiency (CTE) by designing a parametric study based on location, shape, and stiffness of simulated tumors. The authors also compare their findings to a commonly used elastography phantom. The 3D breast software phantom is flexible in shape, size, and location of tumors, glandular to fatty content, and the ductal structure. Residual modulus, maps, and profiles, served as a guide to optimize meshing of this geometrically nonlinear phantom for biomechanical modeling of elastography. At best, low residues (around 1-5 KPa) were found within the phantom while errors were elevated (around 10-30 KPa) at tumor and lobule boundaries. From our FEM analysis, the breast phantom generated a superior CTE in both 2D and in 3D over the block phantom. It also showed differences in CTE values and strain contrast for deep and shallow tumors and showed significant change in CTE when 3D modeling was used. These changes were not significant in the block phantom. Both phantoms, however, showed worsened CTE values for increased input tumor-background modulus contrast. Block phantoms serve as a starting tool but a next level phantom, like the proposed breast phantom, will serve as a valuable intermediate for elastography simulation before clinical testing. Further, given the CTE metrics for the breast phantom are superior to the block phantom, and vary for tumor shape, location, and stiffness, these phantoms would enhance the study of elastography contrast. Further, the use of 2D phantoms with plane strain approximations overestimates the CTE value when compared to the true CTE achieved with 3D models. Thus, the use of 3D phantoms, like the breast phantom, with no approximations, will assist in more accurate estimation of modulus, especially valuable for 3D elastography systems.

The emergence of diagnostic imaging technologies in breast cancer: discovery, regulatory approval, reimbursement, and adoption in clinical guidelines.

In this article, we trace the chronology of developments in breast imaging technologies that are used for diagnosis and staging of breast cancer, including mammography, ultrasonography, magnetic resonance imaging, computed tomography, and positron emission tomography. We explore factors that affected clinical acceptance and utilization of these technologies from discovery to clinical use, including milestones in peer-reviewed publication, US Food and Drug Administration approval, reimbursement by payers, and adoption into clinical guidelines. The factors driving utilization of new imaging technologies are mainly driven by regulatory approval and reimbursement by payers rather than evidence that they provide benefits to patients. Comparative effectiveness research can serve as a useful tool to investigate whether these imaging modalities provide information that improves patient outcomes in real-world settings.

P2-09-03: Breast Cancer Detection Using a Novel Functional Imaging Device Equipped with Multiparametric Computer Analysis.

Abstract Introduction: A novel prototype system performing functional three-dimensional (3D) infrared imaging (RUTH), coupled with multi-parametric computer analysis (MIRA), was evaluated for non-invasive breast cancer detection. The technique utilizes non-ionizing radiation and automatically provides risk assessment based on parameters derived from a clinically known training set. Materials and methods: Following IRB approval, prospective multi-center, two-armed blinded evaluation, was performed on 102 women, which included 43 patients with biopsy proven breast cancer and 59 women with a normal (BI-RADS 1) mammogram. RUTH imaging (Real Imaging Ltd, Israel) was acquired on a continuous temporal timeline for 5 minutes during which a cold-stress test was applied for one minute. Acquired data were analyzed using multiple computed algorithms (MIRA) which were combined to develop a master algorithm for risk assessment of breast cancer. Analysis was blinded to the clinical status. Results were displayed as risk assessment scale with 100 being suspicious for breast cancer and −100 inferring normal healthy breasts. Results Thirty-nine of 43 cancers (91.7%) were identified using this novel technology. The sensitivity and specificity of RUTH coupled with MIRA for detecting breast cancer were 90.7% and 67.8% respectively. The AUC defined by the ROC curve was 0.832. Twenty-seven of the 39 (70%) detected cancers were smaller than 20mm in size. Conclusions: This preliminary study shows adequate performance of the novel technology examined for detecting breast cancer. Performance is comparable to the reported performance of new adjunctive breast imaging technologies such as tomosynthesis and contrast-enhanced mammography, and superior to the published sensitivity of mammography. Our results warrant further evaluation of the RUTH and MIRA technologies in detecting and characterizing breast cancer. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-09-03.

Abstract B9: Community strategies for investigating the biology of breast and cervical cancer initiation in African-American women

Abstract Background: African-American women have the highest overall cancer death rate from breast and cervical cancer and shortest survival of any racial and ethnic group in the United States. These disparities are heightened in the Southern United States. For example, the US breast cancer death rate is 23.0 (per 100,000) for Caucasian women, as compared to 34.3 for African-American women. The North Carolina breast cancer death rate is 27.2 for Caucasian women and 38.0 for African Americans; and in our study area, Durham County, the breast cancer death rate is 27.5 for Caucasians and 42.0 for African-Americans. The causes of these inequalities are complex and interrelated, but arise, at least in part, from disparities in income, education, nutrition, and access to healthcare. For complex historical reasons, African-Americans have had mixed experiences in accessing care and in the quality of care they receive. In addition, distrust has arisen within the African-American community regarding the intents and purposes of health care researchers. Cutting edge breast imaging technology, prevention, and early detection trials exist at academic that could potentially improve early diagnosis and increase our chance of understanding the complex relationship between disparities, genetics, diet, and the environment in promoting breast cancer. Lack of access, mistrust, and community barriers all play a key role in preventing young African-American women from benefiting from state-of-the-art breast imaging and new strategies for early detection of breast and cervical cancer. Methods and Results: To address the unacceptably high death rate among young African-American women from breast and cervical cancer, we have used a multi-disciplinary intervention that includes: 1) community Navigators, 2) access to breast and cervical cancer prevention and early detection services through free community clinics, 3) community partnered breast and cervical cancer prevention trials, and 4) opportunities for mentorship and career development. As a result, we have been able to improve access to early detection strategies in a community based setting and have provided mentorship for 27 young Minority scholars to enter medical school and graduate programs. Our community based breast MRI trial for underserved women has performed over 600 breast MRI since 2004. Over 50% of these women entered in this trial are Women-of-Color. Conclusion: A community based strategy can be highly successful for improving early detection of breast and cervical cancer but only if there is community participation during the initiation of clinical trials and joint community-academic mentorship of young Minority Scholars. Citation Information: Cancer Epidemiol Biomarkers Prev 2011;20(10 Suppl):B9.

TU-A-301-03: A Multi-Dimensional Description of Breast Anatomy Using Breast CT

Purpose: Accurate anatomical characterization of the breast is useful in breast phantom development, computer modeling of breast imagingtechnologies, and computer‐aided diagnosis of various imaging tasks. Using the breast CT (bCT) data sets of women from a clinical trial, a number of two‐dimensional (2D) and three‐dimensional (3D) parameters which describe breast shape and composition are presented. Methods: The diameter, length, and volume of the pendant breast were measured for 219 bCT data sets, grouped by bra cup size. Segmented bCT data sets were used to determine the volume glandular fraction (VGF). VGF was found as a function of patient age, BIRADS density, and bra cup size. The glandular fraction was examined in coronal (GFcoronal ) and sagittal (GFsagittal ) planes of the breast, and the radial distribution of breast glandular fraction (RGFn) within a coronal bCT image was examined for three breast regions. The areal glandular fraction (AGF) was estimated from 2D projections of the breast (simulated by linear integration of bCT data sets) and was compared to the corresponding VGF. A 3D probability map of fibroglandular distribution was simulated using the breast metrics found in this study. Results: Breast diameter, length, and volume increase with increasing bra cup size. VGF was lower among older women and those with larger bra cup size. For each increasing BIRADS category, VGF increased by 5.62% (p < 0.001). VGF was also found to increase with AGF following a power function. Most fibroglandular tissue was distributed mainly in the central portion of the breast. Conclusions: Breast anatomy was examined and a number of parameters were described. The reported data may provide useful information for breast modeling in various imaging or dosimetry tasks.

The evolving role of new imaging methods in breast screening

The potential to avert breast cancer deaths through screening means that efforts continue to identify methods which may enhance early detection. While the role of most new imaging technologies remains in adjunct screening or in the work-up of mammography-detected abnormalities, some of the new breast imaging tests (such as MRI) have roles in screening groups of women defined by increased cancer risk. This paper highlights the evidence and the current role of new breast imaging technologies in screening, focusing on those that have broader application in population screening, including digital mammography, breast ultrasound in women with dense breasts, and computer-aided detection. It highlights that evidence on new imaging in screening comes mostly from non-randomised studies that have quantified test detection capability as adjunct to mammography, or have compared measures of screening performance for new technologies with that of conventional mammography. Two RCTs have provided high-quality evidence on the equivalence of digital and conventional mammography and on outcomes of screen-reading complemented by CAD. Many of these imaging technologies enhance cancer detection but also increase recall and false positives in screening.

The characterization of breast anatomical metrics using dedicated breast CT

Accurate anatomical characterization of the breast is useful in breast phantom development and computer modeling of breast imaging technologies. Capitalizing on the three-dimensional capabilities of dedicated breast CT (bCT), a number of parameters which describe breast shape and fibroglandular distribution are defined. Among 219 bCT data sets, the effective diameter and length of the pendant breast as well as the breast volume were measured and characterized for each bra cup size. The volume glandular fraction (VGF) was determined as a function of patient age, BIRADS density, bra cup size, and breast diameter. The glandular fraction was examined in coronal and sagittal planes of the breast, and the radial distribution of breast glandular fraction within a coronal bCT image was examined for three breast regions. The areal glandular fraction (AGF) was estimated from two-dimensional projections of the breast (simulated by projecting bCT data sets) and was compared to the corresponding VGF. The effective breast diameter and length increase with increasing bra cup size. The mean breast diameters (+/- standard error) of bra cup sizes A/AA, B, C, and D/DD were 11.1 +/- 0.5, 11.4 +/- 0.3, 13.0 +/- 0.2, and 13.7 +/- 0.2 cm, respectively. VGF was lower among older women and those with larger breast diameter and larger bra cup size. VGF increased as a function of the reported BIRADS density. AGF increased with VGF. Fibroglandular tissue was distributed primarily in the central portion of the breast. Breast metrics were examined and a number of parameters were defined which may be useful for breast modeling. The reported data may provide researchers with useful information for characterizing the breast for various imaging or dosimetry tasks.

Diagnosis of breast cancer in women age 40 and younger: delays in diagnosis result from underuse of genetic testing and breast imaging

Background The impact of newer breast imaging technologies and genetic testing on the detection of breast cancer in women age 40 and younger remains unknown. Methods A records review identified 628 women age 40 and younger diagnosed with breast cancer from 1996 to 2008. Patient and tumor characteristics, means of diagnosis, imaging results, and genetic testing were examined. Results Tumors were first detected by self-examination in 71%, with a median invasive tumor size of 2.0 cm. Imaging performed at or after diagnosis visualized most tumors; mammography visualized 86%, magnetic resonance imaging (MRI) visualized 96%, and mammography plus MRI visualized more than 98% of tumors. For 81% of patients, the mammogram at diagnosis was their first mammogram. Although 50% had a family history of breast or ovarian cancer, few underwent genetic testing before their cancer diagnosis; 61 of 247 (25%) ultimately tested had a BRCA mutation. Conclusions Better use of genetic testing, mammography, and MRI could improve breast cancer detection in young women.

Cone-Beam Computed Tomography for Breast Imaging

This article reviews the many modalities used today in the screening and diagnostic work-up of breast cancer, the second most common cause of cancer (after skin cancer) and the second most common cause of cancer death (after lung cancer) in women in the United States today. Newer technologies in breast imaging are also described, in particular the Cone Beam Computed Tomography (CBCT) as developed at the University of Rochester Medical Center. CBCT is a three-dimensional imaging modality which has potential in the screening and diagnostic work-up of women who may have breast cancer. Pilot studies show good coverage of the breast with adequate visualization of parenchymal detail and acceptable radiation dose in comparison with the gold standard of mammography.

TU‐D‐342‐01: Advances in Breast Imaging

Over the last decade, there have been tremendous advances in breast imaging. As many facilities make the transition from film screen to digital mammography, it is appropriate to examine the accomplishments of the past and to acknowledge current technological limitations. In addition, we should carefully study evolving technologies in breast imaging with the goal of developing highly sensitive and highly specific techniques. This presentation will examine recent progress in digital mammography, including contrast‐enhanced imaging, tomosynthesis, and breast CT, from a breast imager's perspective.Randomized clinical trials and meta‐analyses have shown that screening mammography results in a decrease in breast cancer mortality. Although mammography is efficacious in most women, we know that mammography is not a perfect test, epecially in women with radiographically dense breasts. Furthermore, false positive and false negative mammograms are difficult to eliminate. As digital mammography replaces film screen mammography in many practice settings, cancer detection rates may rise slightly and call back rates may decrease slightly.Overlapping densities and areas of dense tissue often make interpretation of film screen mammograms difficult. Overlapping parenchyma and dense tissue hinder digital mammography less than film screen mammography, but these overlying structures are not eliminated with digital mammography. Major efforts have been made in digital tomosynthesis and breast CT in order to advance beyond projection imaging. Tomosynthesis involves the acquisition of tomographic images in the digital mammography unit, while breast CT is based on a volumetric acquisition with the patient positioned prone in a machine that is similar to a unit used for stereotactic biopsies.Conventional digital mammography, digital tomosynthesis, and breast CT may be combined with the injection of iodinated contrast material in order to visualize tumor vascularity and increase the conspicuity of breast tumors. These techniques may also be used to monitor response to neoadjuvant chemotherapy.Over the next decade, tomosynthesis and breast CT will transition from research applications to clinical realities. Further studies are needed in order to determine how to use these emerging tools in an effective, efficacious manner.Educational Objectives:1. To review advances in breast imaging over the last decade.2. To understand the strengths and weaknesses of film screen and digital mammography.3. To appreciate the potential roles of digital tomosynthesis and breast CT.4. To understand the application of iodinated contrast material in digital mammography, tomosynthesis, and breast CT.

Diagnostic algorithm: How to make use of new 2D, 3D and 4D ultrasound technologies in breast imaging

The aim of this publication is to present a time saving diagnostic algorithm consisting of two-dimensional (2D), three-dimensional (3D) and four-dimensional (4D) ultrasound (US) technologies. This algorithm of eight steps combines different imaging modalities and render modes which allow a step by step analysis of 2D, 3D and 4D diagnostic criteria. Advanced breast US systems with broadband high frequency linear transducers, full digital data management and high resolution are the actual basis for two-dimensional breast US studies in order to detect early breast cancer (step 1). The continuous developments of 2D US technologies including contrast resolution imaging (CRI) and speckle reduction imaging (SRI) have a direct influence on the high quality of three-dimensional and four-dimensional presentation of anatomical breast structures and pathological details. The diagnostic options provided by static 3D volume datasets according to US BI-RADS analogue assessment, concerning lesion shape, orientation, margin, echogenic rim sign, lesion echogenicity, acoustic transmission, associated calcifications, 3D criteria of the coronal plane, surrounding tissue composition (step 2) and lesion vascularity (step 6) are discussed. Static 3D datasets offer the combination of long axes distance measurements and volume calculations, which are the basis for an accurate follow-up in BI-RADS II and BI-RADS III lesions (step 3). Real time 4D volume contrast imaging (VCI) is able to demonstrate tissue elasticity (step 5). Glass body rendering is a static 3D tool which presents greyscale and colour information to study the vascularity and the vascular architecture of a lesion (step 6). Tomographic ultrasound imaging (TUI) is used for a slice by slice documentation in different investigation planes (A-,B- or C-plane) (steps 4 and 7). The final step 8 uses the panoramic view technique (XTD-View) to document the localisation within the breast and to make the position of a lesion simply reproducible.

TU‐C‐L100F‐01: New Issues in Breast Imaging

TU‐C‐L100F‐01: New Issues in Breast Imaging

Present and Future of Breast Imaging Technology

Present and Future of Breast Imaging Technology

Industry Perspective: Maximizing the Benefit of Improved Detection with Guided and Monitored Thermal Ablation of Small Tumors

The continuous growth of mammography is driven by global acceptance of the demonstrated ability of screening mammography to reduce mortality from breast cancer. An increasing number of benign and malignant tumors are being diagnosed as a result of the growth in mammography, improvements in technology, especially digital mammography, as well as by an increase in patient surveillance. Breast imaging technology for cancer screening continues to improve, with the integration of ultrasound with digital mammography showing promise that an even larger number of small abnormalities will be detected in screening programs. The results of minimally invasive ablative techniques as tested in pilot clinical studies for breast tumor ablation are reviewed. A new x-ray based thermal monitoring method is described. An improved ability to intraoperatively monitor thermal ablative methods may enable more accurate minimally invasive treatment of an ever increasing number of both benign and malignant breast tumors.

New Technologies in Breast Imaging

Large, randomized controlled trials have proven the efficacy of mammography in reducing breast cancer mortality. However, the known deficiencies of mammography have led to the development of new technologies. Magnetic resonance imaging (MRI), digital mammography, computer-assisted diagnosis, positron-emission tomography (PET), technetium 99m sestamibi, and expanding roles for breast ultrasound have been explored as tools in breast cancer detection and evaluation. This article discusses these modalities and their current uses.

Study design in the evaluation of breast cancer imaging technologies

Bringing a new imaging technology to market is a complex process. Beyond conceptualization and proof of concept, obtaining U.S. Food and Drug Administration (FDA) approval for clinical use depends on the documented experimental establishment of safety and efficacy. In turn, safety and efficacy are evaluated in the context of the intended use of the technology. The purpose of this study was to examine a conceptual framework for technology development and evaluation, focusing on new breast imaging technologies as a highly visible and current case in point. The FDA views technology development in terms of a preclinical and four clinical phases of assessment. With a concept of research and development as a learning model, this phased-assessment concept of regulatory review against intended use was integrated with a five-level version of a hierarchy-of-efficacy framework for evaluating imaging technologies. Study design and analysis issues are presented in this context, as are approaches to supporting expanded clinical indications and new intended uses after a new technology is marketed. Breast imaging technologies may be intended for use as replacements for standard-of-care technologies, as adjuncts, or as complementary technologies. Study designs must be appropriate to establish claims of superiority or equivalence to the standard for the intended use. Screening technologies are ultimately judged on their demonstrated effectiveness in decreasing cause-specific mortality through early detection, but they may be brought to market for other uses on the basis of lesser standards of efficacy (eg, sensitivity, specificity, positive and negative predictive value, and stage of disease detected).

How new technology is changing mammography and breast cancer management.

Breast-imaging technology has improved in ways that allow one not only to detect breast cancer earlier, but also to distinguish benign from malignant lesions better. These capabilities are influencing the approach to breast cancer. We review current trends and issues for the non-radiologist.

Current and future technologies for breast cancer imaging.

Breast cancer is one of the most frequently diagnosed malignancies and the second leading cause of cancer deaths in American females [1]. Several improvements in diagnostic protocols have enhanced our ability for earlier detection of breast cancer, resulting in improvement of therapeutic outcome and an increased survival rate for breast cancer victims [2,3,4]. The importance of early detection of breast tumors therefore cannot be overemphasized. Current early screening techniques are, however, neither comprehensive nor infallible, especially in women with radiographically dense breasts. Recent data from the Edinburgh randomized trial of breast screening as well as other retrospective analyses of 'false-negative' mammograms demonstrate that approximately one-third of diagnosed cancers were visible on early 'negative' mammograms [2,5,6]. Early detection of breast cancer therefore still presents a significant diagnostic challenge. Imaging techniques that improve breast cancer detection, localization, and evaluation of therapy would be a major breakthrough in combating the disease. Detection of malignant tumor cells in a background of normal or hyperplastic benign tissue is often based on differences in physical properties between tissues, which are frequently minimal (eg proton relaxation times, X-ray absorption, ultrasound scattering), resulting in low contrast resolution; that is, small tumors are not detectable. To enhance detection of small tumors, several groups have been developing the concept of molecular imaging as a way to increase the signal to noise ratio by detecting the differences in 'molecular properties' between cancer and normal tissues that arise as a result of malignant transformation. This should, in theory, allow for earlier detection of smaller tumors. The following reviews in this series will describe how state-of-the-art imaging modalities (magnetic resonance [MR] imaging, magnetic resonance spectroscopy, nuclear imaging, and optical imaging) are being used to more precisely identify human breast tumors and monitor chemotherapeutic response. Not all of the cited technologies are yet able to take advantage of the underlying molecular properties resulting in altered tumor biology; however, many have been developed to the point of being able to exploit macromolecular changes in tumor physiology and/or metabolism to increase detection of diseased tissue. Part of the problem in exploiting the underlying molecular changes manifest as altered physiology or metabolism is the lack of genetic information. As advances in gene profiling allow dissection of underlying molecular profiles of tumors, imaging approaches will be more molecularly based. Uncovering and understanding the molecular aberrations directly underlying the measurable biological differences, as examples from our own work demonstrate (see below), will allow molecular refinement of the imaging tools and, presumably, more sensitive tumor detection.