X-Ray Phase Contrast Imaging Concepts and Systems

National Heart, Lung, And Blood Institute

Investigators

Linked publications & trials

Abstract

Introduction: My group is focused on the development of X-Ray imaging techniques for clinical and research applications. In the US 72% of medical imaging procedures involve X-rays such as radiography, angiography, CT and image guided interventional procedures. We tackle two major challenges shared by these modalities, which are the lack of tissue specificity and the concern of ionizing radiation exposure. We take advantage of the wave nature of x-rays to add two new dimensions to the image contrast. These are wave scattering and refractive bending. Wave scattering reveals microscopic structures which is independent from the conventional attenuation contrast. Materials that are indistinguishable by x-ray attenuation can be separated in the scattering dimension, similar to the benefit of 2D versus 1D gel electrophoresis. Refractive bending, or phase contrast, offers the potential of significant dose reduction since it arises from the refractive index variations in the body and does not require energy absorption. The wave nature of x-ray also opens avenues for shaping the x-ray beam with advanced optics for the purpose of measuring x-ray refraction and diffraction in tissue. Our accomplishments: This year the concept, hardware and software we developed for x-ray imaging have been adapted to neutron precision imaging and measurements in a collaboration with NIST. We obtained first measurements in exploring transparent x-ray optics that enable high-resolution wave imaging. Animal studies lead to a precise understanding of the role and boundary conditions of wave imaging for biological applications, and motivated a new stage of technical development centered on high-resolution imaging. Future plan: this year we entered into a new phase of the project which focuses on transparent x-ray optics and high-resolution imaging, with the aim of improving pathology analysis of biopsy tissue specimen.