Design and construction of an X-ray phase-contrast mammography prototype for the in-vivo investigation of early breast cancer

Left: GI on the Philips Microdose Mammography Setup. Right: Gold grating with p2=1.3 μm, a height of 16 μm and a duty cycle of 0.5.

This project consists of the development of a grating-based phase contrast mammography prototype for the in-vivo investigation of breast cancer. Clinically, we aim at improving the diagnostic power of mammography by exploiting the additional information provided by differential phase and dark-field signals. To this end, our approach is to design and build a grating interferometer (GI) that can be fitted into a Philips Microdose Mammography setup, which already fulfills the requirements of a clinical setting [1, 2]. To define the parameters of this GI, we developed an optimization method based on maximizing the sensitivity to phase and dark-field changes taking into account the geometric and grating fabrication constraints. The phase sensitivity was defined as the minimum detectable electron density gradient, whereas the dark-field sensitivity was expressed as the corresponding signal-to-noise ratio (SNR) [3]. In addition, we have investigated alternatives to retrieve and reconstruct the new additional signals that can be compatible with the Philips setup acquisition mode [4]. The first prototype [5] has been installed in University Hospital Zurich in July 2020 for clinical trial.