Initial Results from a High-Energy X-Ray Inline Phase Sensitive Breast Tomosynthesis (PBT) Prototype System

X-ray phase sensitive imaging has been employed in the preclinical settings for more than two decades. Advancements in the technology has allowed to potentially translate this innovative imaging technique to the clinical environment. Inline phase sensitive imaging technique has shown promising potential to be used for breast cancer imaging. A high energy phase sensitive breast tomosynthesis (PBT) prototype system based on the inline phase sensitive imaging technique has been developed for the potential imaging in clinical environment. The prototype system incorporates a microfocus x-ray tube and a flat panel detector having a pixel pitch of 70 mu m. The microfocus x-ray tube has a tungsten (W) anode, Beryllium (Be) output window and a focal spot size that ranges from 18-50 mu m, depending on the output power. The x-ray tube/detector configuration produces a geometric magnification (M) of 2.2 and acquires 9 projection views within 15 degrees or 30 projection views within 30 degrees in stop-and-shoot scanning mode. A single distance phase retrieval scheme method based on the Phase-Attenuation Duality (PAD) principle is applied to the angular projection views. A filtered back-projection operation reconstructs a set of tomogram slices at 1mm incremental depth within the breast along the z-direction. American College of Radiology phantom images demonstrate that both 2D and tomosynthesis images acquired on the prototype system meet the minimum criteria set by the Mammography Quality Standard Act. We have also imaged mastectomy specimens with the PBT prototype system at the University of Utah Huntsman Cancer Hospital. PBT 2D images and tomosynthesis image slices demonstrate image quality comparable to a conventional digital breast tomosynthesis clinical system.