Digital mammography

Optical imaging for breast cancer prescreening

Breast cancer prescreening is carried out prior to the gold standard screening using X-ray mammography and/or ultrasound. Prescreening is typically carried out using clinical breast examination (CBE) or self-breast examinations (SBEs). Since CBE and SBE have high false-positive rates, there is a need for a low-cost, noninvasive, non-radiative, and portable imaging modality that can be used as a prescreening tool to complement CBE/SBE. This review focuses on the various hand-held optical imaging devices that have been developed and applied toward early-stage breast cancer detection or as a prescreening tool via phantom, in vivo, and breast cancer imaging studies. Apart from the various optical devices developed by different research groups, a wide-field fiber-free near-infrared optical scanner has been developed for transillumination-based breast imaging in our Optical Imaging Laboratory. Preliminary in vivo studies on normal breast tissues, with absorption-contrasted targets placed in the intramammary fold, detected targets as deep as 8.8 cm. Future work involves in vivo imaging studies on breast cancer subjects and comparison with the gold standard X-ray mammography approach.

Modern breast cancer detection: a technological review

Breast cancer is a serious threat worldwide and is the number two killer of women in the United States. The key to successful management is screening and early detection. What follows is a description of the state of the art in screening and detection for breast cancer as well as a discussion of new and emerging technologies. This paper aims to serve as a starting point for those who are not acquainted with this growing field.

Digital mammography: are there advantages in screening for breast cancer?

Digital mammography separates the processes of image acquisition, processing, and display, which allows for the optimization of each process. The result addresses some of the limitations of screen film mammography. This work reviews the advantages of the decoupling of the processes and the clinical trials comparing digital mammography with film-screen mammography in the screening setting. Advanced applications of digital mammography, such as contrast-enhanced digital mammography and tomosynthesis, are also discussed.

Mamografia digital: perspectiva atual e aplicações futuras

Na mamografia digital, os processos de aquisição da imagem, demonstração e armazenamento são separados, o que leva à otimização de cada uma dessas etapas. A radiação transmitida através da mama é absorvida por um detector eletrônico, em resposta fiel a uma ampla variedade de intensidades. Uma vez que esta informação é armazenada, ela pode ser demonstrada usando técnicas computadorizadas de imagem, permitindo variações de brilho e contraste e ampliação, sem a necessidade de exposições radiológicas adicionais para a paciente. Neste artigo, o estado atual da tecnologia em mamografia digital e dados sobre testes clínicos que dão suporte ao uso dessa tecnologia são revistos. Além disso, algumas aplicações potencialmente utilizáveis que estão sendo desenvolvidas com a mamografia digital são descritas.

Soft copy display requirements for digital mammography

One of the advantages of digital mammography is to display mammograms on softcopy (electronic displays). Softcopy display of mammography is challenging because of the spatial and contrast resolution demands present in mammograms. We have designed and developed a softcopy mammography display application, Mammoview, which is capable of allowing radiologists to read mammograms as quickly and as accurately as they can on film alternators. We review the studies using Mammoview to elucidate the requirements of a successful softcopy display station. The design and development of the Mammoview softcopy display station are described in this article, and results of several studies using Mammoview are reported, including subjective feedback from Radiological Society of North America (RSNA) conference demonstrations, and clinical studies measuring performance in terms of speed and accuracy. Additional analysis of user interactions and user feedback is used to study the successes and shortcomings of mammography display stations like Mammoview. Overall, radiologist readings using Mammoview have been shown to be as fast and as accurate as readings using mammography film alternators. However, certain parts of the softcopy interface were more successful than their film counterparts, whereas others were less successful. Data analysis of the recorded human-computer interactions for the softcopy component of the clinical trial indicate statistically significant correlations between the difference in review time of softcopy versus alternator readings and three factors: the number of interactions, the reader, and the size of the image being reviewed. The first factor (number of interactions) suggests that simpler interfaces require less time to use; the second factor, the reader, supports previous findings that radiologists vary in how fast they read screening mammography studies; the third, size of image, suggests that the speed of softcopy review is increased relative to film readings when images are significantly larger than the display size. Feedback from radiologists using the system in clinical trials and at demonstration exhibits at RSNA indicated good acceptance of the interface and easy adaptation. Radiologists indicated that they felt comfortable using the interface, and that they would use such a softcopy interface in clinical practice. Finally, preliminary work suggests that the addition of a simple interaction to incorporate computer-aided detection (CAD) results would improve reading accuracy without significantly increasing reader times.

New modalities in breast imaging: digital mammography, positron emission tomography, and sestamibi scintimammography

Digital mammography, PET, and sestamibi scintimammography are three new modalities in breast imaging. DM has advantages over film-screen mammography in image storage, retrieval, and processing and may lower the recall rate. Computer-aided detection may increase the sensitivity of mammographic screening without a substantial reduction in specificity. Whereas PET and sestambi scintimammography are not useful in breast cancer screening, PET may play a role in detecting nodal metastases and monitoring treatment response, and sestamibi scintimammography in selected cases may serve as an adjunct to conventional imaging. The cost-effectiveness of these new modalities remains to be evaluated, but all have the potential to significantly advance the diagnosis and management of women with breast cancer.

Perspective on digital mammography

Digital mammography, particularly through its advanced applications, holds great promise for improved diagnostic accuracy, but the display of the images is not ideal at present. Clinical softcopy workstations are somewhat unwieldy to use, and image processing has not yet been optimized for each machine or for each clinical task. In addition, the cost-effectiveness and accuracy of the technology warrant careful study before digital mammography becomes widely disseminated and potentially replaces screen-film mammography, a technology that has been well documented to reduce breast cancer mortality.

What every surgical oncologist should know about digital mammography

This article reviews the available information on digital mammography for surgeons who care for patients with breast cancer. The limitations of the current film-based technology and why digital mammography promises to improve breast cancer detection and breast lesion diagnosis are described. The basics of digital imaging technology are reviewed, including a description of image contrast and spatial resolution and its variance from currently available clinical digital mammography systems. The results of clinical trials completed to date are reported. An upcoming large screening trial for digital mammography, sponsored by the National Cancer Institute, is described. Future technological developments, including improvements in softcopy display, image processing, computer-aided detection and diagnosis (CADD), tomosynthesis, and digital subtraction mammography (DSM), are briefly discussed.