Phase-Sensitive Region-of-Interest Computed Tomography

TL;DR

This paper introduces a novel phase-sensitive ROI CT method that corrects phase truncation artifacts and enables high-quality, quantitative phase imaging in large specimens, advancing clinical PCI applications.

Contribution

The work presents a new system and reconstruction algorithm for phase-sensitive ROI CT that overcomes size limitations in grating-based PCI, facilitating clinical use.

Findings

High-quality results on simulated data

Successful application on a biological mouse sample

Potential for clinical large-specimen PCI

Abstract

X-Ray Phase-Contrast Imaging (PCI) yields absorption, differential phase, and dark-field images. Computed Tomography (CT) of grating-based PCI can in principle provide high-resolution soft-tissue contrast. Recently, grating-based PCI took several hurdles towards clinical implementation by addressing, for example, acquisition speed, high X-ray energies, and system vibrations. However, a critical impediment in all grating-based systems lies in limits that constrain the grating diameter to few centimeters. In this work, we propose a system and a reconstruction algorithm to circumvent this constraint in a clinically compatible way. We propose to perform a phase-sensitive Region-of-Interest (ROI) CT within a full-field absorption CT. The biggest advantage of this approach is that it allows to correct for phase truncation artifacts, and to obtain quantitative phase values. Our method is robust, and shows high-quality results on simulated data and on a biological mouse sample. This work is a proof of concept showing the potential to use PCI in CT on large specimen, such as humans, in clinical applications.