> Research & Grants
> Grants Program
> Research Grants
> Research Grants Awarded
Contrast-Enhanced Dual Energy Mammography
Mammography (screen film or digital) is used throughout North America for breast cancer screening in asymptomatic patients. Once a suspicious area is identified by mammography, a number of subsequent diagnostic techniques are used as needed including additional mammographic views, ultrasonography, physical breast examination, and breast MRI. In particular, breast MRI is used with increased frequency in the diagnostic breast examination. In breast MRI, gadolinium DTPA is injected intravenously, and often accumulates near the site of a breast tumor due to the leaky vessels recruited by angiogenesis. Tumor identification is achieved when MRI images reveal the location of this contrast agent accumulation. We propose the use of contrast-enhanced dual energy mammography (CEDEM) as a cost effective but potentially diagnostically important alternative to breast MRI. CEDEM requires the injection of an iodine-based contrast agent, which accumulates near the site of a breast tumor in the same way that Gd-DTPA does. Two low-dose x-ray images, each at different x-ray energies, are acquired and combined mathematically to produce a contrast-enhanced image of the breast, which depicts the location of the breast tumor with high sensitivity. A digital x-ray imaging system custom-designed to image the breast is already in our laboratory, and this system will serve as an experimental test-bed for much of the proposed research. The overall goals of this research are to optimize and then evaluate the pre-clinical potential of dual energy contrast-enhanced mammography for breast cancer diagnosis, using three specific aims: (1) computer simulation techniques will be used to identify optimal parameters necessary for maximizing image quality at minimal radiation dose levels, (2) an existing prototype breast scanner will be used for experimental validation of CEDEM, and (3) algorithms for optimizing the subtraction and display of the CEDEM images will be developed and studied on cadaver breast phantoms. Contrast-enhanced MRI has recently been shown to provide significantly better cancer detection than mammography in high-risk women. CEDEM is likely to provide equal detection performance with the benefit of substantially lower cost and much better availability than breast MRI. The research outlined in this proposal is the necessary first step to a clinical trial, which will evaluate the efficacy of contrast-enhanced mammography in living patients.
Breast cancer screening is recommended by the National Cancer Institute and the American Cancer Society, and mammography is used as the primary screening test for breast cancer. When a radiologist sees a suspicious area on a screening mammogram, she will often prescribe other imaging procedures to increase her confidence in the diagnosis. Additional imaging studies are part of a diagnostic breast examination, and include additional x-ray images, ultrasonography, and breast magnetic resonance imaging (MRI). With breast MRI, a contrast agent is injected into the woman’s arm vein, and MRI images of the breast are taken a few minutes later. The contrast agent in many cases passes through the vessels in the woman’s breast, but at the site of a tumor, the contrast agent leaks out from the vessels into the surrounding tissue spaces. Breast MRI techniques are very sensitive in identifying the tumor sites of these “leaky” vessels. In this application, we propose to study the use of x-ray imaging techniques coupled with contrast agent injection, that will produce images with very similar information as breast MRI, but at substantially less cost and using equipment that is much more widely available. The woman would have an IV injection in her arm, and a few minutes later she would have a few x-ray images produced of her breast (similar to mammography, except with less compression). The images produced are mathematically manipulated in the computer, to emphasize any contrast agent that may have leaked out near the site of a tumor in the breast. In this study, computer simulation techniques and physical experiments on a breast imaging system already in our laboratory will be used to determine the most optimum technical factors for imaging women using the proposed technique. If our testing demonstrates strong efficacy for contrast-enhanced dual energy mammography, we intend to (after the end of this grant period) conduct contrast-enhanced dual energy mammography on patients who would also be getting breast MRI procedures at our institution. Thus, the optimization techniques and further validation described in this proposal are the necessary steps required to translate contrast-enhanced mammography to the clinical setting. We believe that the use of this technique will improve breast cancer diagnoses in a cost effective manner, and will lead to better screening sensitivity and fewer negative breast biopsies.