Laurie L. Fajardo

Diagnostic Accuracy of Digital versus Film Mammography: Exploratory Analysis of Selected Population Subgroups in DMIST

PURPOSE To retrospectively compare the accuracy of digital versus film mammography in population subgroups of the Digital Mammographic Imaging Screening Trial (DMIST) defined by combinations of age, menopausal status, and breast density, by using either biopsy results or follow-up information as the reference standard. MATERIALS AND METHODS DMIST included women who underwent both digital and film screening mammography. Institutional review board approval at all participating sites and informed consent from all participating women in compliance with HIPAA was obtained for DMIST and this retrospective analysis. Areas under the receiver operating characteristic curve (AUCs) for each modality were compared within each subgroup evaluated (age < 50 vs 50-64 vs >or= 65 years, dense vs nondense breasts at mammography, and pre- or perimenopausal vs postmenopausal status for the two younger age cohorts [10 new subgroups in toto]) while controlling for multiple comparisons (P < .002 indicated a significant difference). All DMIST cancers were evaluated with respect to mammographic detection method (digital vs film vs both vs neither), mammographic lesion type (mass, calcifications, or other), digital machine type, mammographic and pathologic size and diagnosis, existence of prior mammographic study at time of interpretation, months since prior mammographic study, and compressed breast thickness. RESULTS Thirty-three centers enrolled 49 528 women. Breast cancer status was determined for 42,760 women, the group included in this study. Pre- or perimenopausal women younger than 50 years who had dense breasts at film mammography comprised the only subgroup for which digital mammography was significantly better than film (AUCs, 0.79 vs 0.54; P = .0015). Breast Imaging Reporting and Data System-based sensitivity in this subgroup was 0.59 for digital and 0.27 for film mammography. AUCs were not significantly different in any of the other subgroups. For women aged 65 years or older with fatty breasts, the AUC showed a nonsignificant tendency toward film being better than digital mammography (AUCs, 0.88 vs 0.70; P = .0025). CONCLUSION Digital mammography performed significantly better than film for pre- and perimenopausal women younger than 50 years with dense breasts, but film tended nonsignificantly to perform better for women aged 65 years or older with fatty breasts.

Breast Tomosynthesis: Present Considerations and Future Applications

Mammography is an effective imaging tool for detecting breast cancer at an early stage and is the only screening modality proved to reduce mortality from breast cancer. However, the overlap of tissues depicted on mammograms may create significant obstacles to the detection and diagnosis of abnormalities. Diagnostic testing initiated because of a questionable result at screening mammography frequently causes patients unnecessary anxiety and incurs increased medical costs. Breast tomosynthesis, a new tool that is based on the acquisition of three-dimensional digital image data, could help solve the problem of interpreting mammographic features produced by tissue overlap. Although the technology has not yet been approved by the Food and Drug Administration, breast tomosynthesis has the potential to help reduce recall rates, improve the selection of patients for biopsy, and increase cancer detection rates, especially in patients with dense breasts. Supplemental material available at radiographics.rsnajnls.org/cgi/content/full/27/S231/DC1.

Stereotactic core-needle biopsy of the breast: A report of the Joint Task Force of the American College of Radiology, American College of Surgeons, and College of American Pathologists

A national task force consisting of members from the American College of Radiology, the American College of Surgeons, and the College of American Pathologists examined the issues surrounding stereotactic core-needle biopsy for occult breast lesions. Their report includes indications and contraindications, informed consent, specimen handling, and management of indeterminate, atypical, or discordant lesions.

Near-infrared optical imaging of the breast with model-based reconstruction

RATIONALE AND OBJECTIVES Near-infrared diffuse optical imaging may offer enhanced contrast resolution over that of the existing technologies for detection and diagnosis of breast cancer. The authors report quantitative absorption and scattering images of the human breast with model-based reconstruction methods using near-infrared continuous-wave tomographic data. MATERIALS AND METHODS An automatic, multichannel optical imaging system was used to image the breasts of nine women: four with infiltrating ductal carcinomas, one with infiltrating lobular carcinoma, one with fibroadenoma, and three control subjects with no breast lesion. The image reconstruction methods are centered on the finite element solution of photon diffusion in breast tissue. RESULTS Substantial contrast between tumor and adjacent parenchyma was observed. Images of the control subjects showed homogeneous optical features. In the six women with breast lesions, the locations and sizes of tumors imaged optically were accurate and consistent with the mammographic findings. CONCLUSION The results of this pilot study show that cancers as small as 5 mm can be quantitatively imaged. In addition, preliminary data from the scattering images suggest that benign and malignant tumors can be noninvasively differentiated with optical imaging.

Differentiation of cysts from solid tumors in the breast with diffuse optical tomography1

RATIONALE AND OBJECTIVES Near-infrared diffuse optical tomography (DOT) is an emerging imaging technology that has the potential to offer enhanced contrast resolution over the existing technologies for detection and diagnosis of breast cancer. Thus far, the clinical evaluation of DOT has been largely limited to solid tumors. A pilot clinical study focused on DOT imaging of breasts with cysts is presented. MATERIALS AND METHODS Six cases were studied using the recently developed compact, parallel-detection DOT system. Images characterizing the tissue absorption and scattering were obtained with a finite element-based reconstruction algorithm. The optical images were compared with the mammograms and sonograms. In one case, in vitro measurements of optical properties were conducted for the fluid obtained from needle aspiration. RESULTS Substantial contrast between cyst and adjacent parenchyma is observed. For the six cases evaluated, the locations and sizes of cysts imaged optically are accurate and consistent with the mammographic and sonographic findings. For the case that aspiration was performed, the absorption and scattering coefficients imaged in the cyst region are quantitatively accurate compared with that measured in vitro from the fluid aspirated. CONCLUSION This pilot study shows that cysts ranging from 1-4 cm in diameter can be quantitatively imaged. They can be differentiated from solid breast tumors because cysts generally demonstrate lower absorption and scattering coefficients compared with the surrounding normal tissue, whereas solid tumors show concurrent higher absorption and scattering related to the normal tissue.

Optimization of exposure parameters in full field digital mammography

Optimization of exposure parameters (target, filter, and kVp) in digital mammography necessitates maximization of the image signal-to-noise ratio (SNR), while simultaneously minimizing patient dose. The goal of this study is to compare, for each of the major commercially available full field digital mammography (FFDM) systems, the impact of the selection of technique factors on image SNR and radiation dose for a range of breast thickness and tissue types. This phantom study is an update of a previous investigation and includes measurements on recent versions of two of the FFDM systems discussed in that article, as well as on three FFDM systems not available at that time. The five commercial FFDM systems tested, the Senographe 2000D from GE Healthcare, the Mammomat Novation DR from Siemens, the Selenia from Hologic, the Fischer Senoscan, and Fujis 5000MA used with a Lorad M-IV mammography unit, are located at five different university test sites. Performance was assessed using all available x-ray target and filter combinations and nine different phantom types (three compressed thicknesses and three tissue composition types). Each phantom type was also imaged using the automatic exposure control (AEC) of each system to identify the exposure parameters used under automated image acquisition. The figure of merit (FOM) used to compare technique factors is the ratio of the square of the image SNR to the mean glandular dose. The results show that, for a given target/filter combination, in general FOM is a slowly changing function of kVp, with stronger dependence on the choice of target/filter combination. In all cases the FOM was a decreasing function of kVp at the top of the available range of kVp settings, indicating that higher tube voltages would produce no further performance improvement. For a given phantom type, the exposure parameter set resulting in the highest FOM value was system specific, depending on both the set of available target/filter combinations, and on the receptor type. In most cases, the AECs of the FFDM systems successfully identified exposure parameters resulting in FOM values near the maximum ones, however, there were several examples where AEC performance could be improved.

Image quality in lossy compressed digital mammograms

Abstract The substitution of digital representations for analog images provides access to methods for digital storage and transmission and enables the use of a variety of digital image processing techniques, including enhancement and computer assisted screening and diagnosis. Lossy compression can further improve the efficiency of transmission and storage and can facilitate subsequent image processing. Both digitization (or digital acquisition) and lossy compression alter an image from its traditional form, and hence it becomes important that any such alteration be shown to improve or at least not damage the utility of the image in a screening or diagnostic application. One approach to demonstrating in a quantifiable manner that a specific image mode is at least equal to another is by clinical experiment simulating ordinary practice and suitable statistical analysis. In this paper we describe a general protocol for performing such a verification and present preliminary results of a specific experiment designed to show that 12 bpp digital mammograms compressed in a lossy fashion to 0.015 bpp using an embedded wavelet coding scheme result in no significant differences from the analog or digital originals.

Signal, noise, and detective quantum efficiency in CCD-based x-ray imaging systems for use in mammography

This paper presents results of experiments performed to find parameters affecting signal, noise and Detective Quantum Efficiency of x-ray imaging systems with potential for use in mammography.

Estimating the cost-effectiveness of stereotaxic biopsy for nonpalpable breast abnormalities: A decision analysis model

RATIONALE AND OBJECTIVES We examined the clinical and economic trade-offs of shifting from surgical excisional biopsy to stereotaxic core breast biopsy for evaluating non-palpable, mammographically detected breast lesions. METHODS A decision analysis model compared strategies beginning with excisional or stereotaxic core biopsy for hypothetical cohorts of 1,000 women. All women with negative initial biopsies had a 6-month follow-up mammogram. Sensitivities and specificities were based on the literature and expert estimates. Pretest probabilities of invasive cancer and in situ cancer were each 10% based on mammographic features. Adjusted costs were based on an audit of patients evaluated at the Medical College of Virginia and physician relative value units. RESULTS Per 1,000 women, with an expected rate of 100 invasive and 100 in situ cancers, the stereotaxic core biopsy strategy would initially miss 6.7 invasive and 12.4 in situ cases. Most of these would be detected at 6-month follow-ups. Of the women having a stereotaxic core biopsy, 75.7% avoided a surgical procedure. Using stereotaxic core biopsy saved

Quality control for digital mammography: Part II recommendations from the ACRIN DMIST trial

804 per woman. Continuing to initially use surgical biopsy, total management costs were an additional