Stationary Digital Tomosynthesis System for Early Detection of Breast Tumors

Early detection is viewed as the best hope to decrease breast cancer mortality by allowing intervention at an earlier stage of cancer progression. The most common and effective early-detection tool for breast cancer is X-ray screening mammography. However, mammography has limitations: About 30% of breast cancers are still missed in traditional mammography. It is particularly difficult for mammography to interpret dense breast tissues, which is common in young women. This is due to the two-dimensional (2D) nature of traditional mammography.

With the new 3D imaging technique of digital mammographic tomosynthesis, one acquires a series of projection images as the X-ray source moves along an arc above the compressed breast. This allows the reconstruction of a set of arbitrary planes in the breast to provide 3D information. Compared with traditional mammography techniques, mammographic tomosynthesis reconstruction methods make it possible to distinguish the cancer from its overlying breast tissues, even for the problematic dense breast cases. This may be greatly helpful at improving breast cancer detection. However, all current commercial prototype digital breast tomosynthesis scanners have several intrinsic limitations: (1) Source rotation leads to long scanning time (~20-50 seconds) and discomfort for patients from breast compression; (2) slow motion of the source leads to motion blurring and system instability that limits the spatial resolution; (3) long scanning time prevents the adaptation of advanced imaging methods such as dual energy, quasi-monochromatic, and k-edge imaging which can provide better contrast and reduce imaging dose.

The objective of this proposal is to develop a novel stationary digital breast tomosynthesis scanner to mitigate the above limitations. This proposed device is based on the new carbon nanotube multi-pixel field emission X-ray (MBFEX) technology invented and demonstrated by our team at University of North Carolina at Chapel Hill. The pixilated and spatially distributed MBFEX source can generate X-ray radiation from multiple views without any mechanical motion of the source, detector, or object. This enables the design of tomography systems with great flexibility in source configuration and imaging sequence. The feasibility of the proposed device has been demonstrated. A proof-of-concept stationary DBT scanner with 25 X-ray pixels covering 48-degree viewing angles has been recently designed and assembled in our lab. Preliminary results of the investigation show that stationary breast tomosynthesis method is capable of providing 3D information of breast.

The goal of this project is to determine the optimal breast tomosynthesis technique to provide 3D information at high resolution and comparable dose to mammography, and with lower cost and hardware requirements compared to other common alternatives such as breast Computed Tomography or breast Magnetic Resonance. After the completion of this project, future clinical trial and application of breast tomosynthesis will be pursued. After completing the Principal Investigator's postdoctoral training, he plans on pursuing a career in breast cancer research. This project will supplement the investigator's training to develop a comprehensive view of breast imaging.