A preclinical large-field-of-view X-ray multi-contrast lung imaging prototype

Abstract

By integrating three absorption gratings with a medical X-ray tube and a medical flat panel detector, a preclinical X-ray multi-contrast lung imaging prototype with a large field-of-view up to 40 × 50 cm2 was developed in this work. The prototype system provides phase-contrast and dark-field images simultaneously in addition to the conventional X-ray absorption imaging. Unlike the traditional grating-based phase-contrast imaging (GPCI) system, the scanning object is placed behind the pattern-generating grating G1, reducing the radiation dose to probably half of the original system design. For a fast scan process, three absorption gratings inducing a large field-of-view were utilized. Besides, the X-ray tube, the three gratings and the detector are all fixed on the same mechanical arm, scanning the object along the vertical direction. A numerical simulation platform was developed to help optimize the imaging parameters. Finally, the preliminary experimental results of a full-body enthanized rabbit demonstrate the capability of the multi-contrast prototype system, and its dark-field images are capable of providing additional diagnostic value for the diagnosis of lung diseases. Direct evaluation of the potential clinical unity of the multi-contrast lung imaging can be further performed on this prototype system.