Breast cancer is the most common cancer among women today. The best current strategy is to detect and treat breast cancer early, before the cancer has a chance to metastasize. Conventional x-ray mammography remains the most commonly used imaging method for early breast cancer detection. However, the sensitivity and specificity are limited in x-ray mammography largely due to its two-dimensional (2D) nature and the consequent structural overlapping. This limitation is exacerbated for radiologically dense breasts in which normal tissue may obscure a cancer. Despite the fact that tremendous progress has been made to improve the detection of cancer masses and of microcalcifications by the introduction of digital breast tomosynthesis and dedicated breast cone- beam CT, one common limitation remains in all current x-ray methods: both breast cancer detection tasks depend on a single x-ray absorption contrast mechanism. The optimal detection performances of these two detection tasks often have competing requirements on spatial resolution and radiation dose. As a result, the performance of both detection tasks is somewhat compromised. The overall objective of this proposal is to develop a multi-contrast x-ray digital mammography and digital breast tomosynthesis imaging system to improve breast cancer detection for women with dense breasts. In this new imaging system, the current absorption-based digital mammography and DBT imaging capability will be maintained with the addition of two supplemental contrast mechanisms: the first utilizes a contrast mechanism based on the x-ray refraction property in soft tissue and permits improved visualization of low contrast masses. The detection of microcalcifications can be accomplished by another concomitant novel x-ray dark field contrast mechanism. Note that all three types of images, viz., absorption image, phase contrast image, and dark field image, are generated from a single data acquisition. Given the fact that the current clinical DBT imaging system enables one to acquire both digital mammography and DBT images, the proposed multi-contrast breast imaging system will be constructed by incorporating an x-ray Talbot-Lau grating interferometer into one of these systems. Novel image reconstruction, processing, and display methods will be developed to help physicians extract the most valuable information from the multi-contrast mammography and DBT images. There are four primary specific aims in this proposal: (1) Optimize and fabricate grating interferometer for the multi-contrast breast imaging system; (2) Integrate gratings into the current clinical DBT systems and perform an experimental characterization of physical performance; (3) Perform quantitative imaging performance assessment and optimize imaging protocols; (4) Perform initial clinical performance evaluation of the multi-contrast imaging system. Upon the completion of this project, the first clinical prototype multi-contrast system will have been constructed for clinical studies. The disease signatures in the acquired multi-contrast DBT images will be understood, and the system will be ready for clinical trial studies in the next stage of the project.
Breast cancer is the most common cancer among women today. Women in the US have a baseline risk of developing breast cancer of approximately 11-12% over the course of their lifetime and between 30% and 40% of these women die from it. In this project, we will develop a new multi-contrast imaging method to provide the earliest possible diagnosis of breast cancer with both high sensitivity and specificity.
