题目：Differential Phase-Contrast Cone Beam CT  

报告人：Weixing Cai

时 间：6月4日（星期一 ）下午2：00
地 点：校医院A534会议室
主持人：任秋实（教授）

报告内容摘要：
    Among the various phase-contrast techniques that have been reported, the different phase-contrast (DPC) technique is the most promising for clinical applications as a hospital-grade x-ray tube can be used for such a system, and the self-imaging effect is implemented through a grating system to manifest phase contrast that shows higher contrast-to-noise ratio (CNR) than conventional absorption contrast. It is also straightforward to develop the DPC technique into a cone beam tomographic imaging technique (DPC-CBCT) to provide three-dimensional information of the linear phase coefficients, which is expected to show a three orders higher contrast and a one or two orders higher CNR. Therefore, it is possible to significantly improve the spatial resolution or reduce the exposure dose level. A bench-top DPC-CBCT system has been developed in our lab, which is composed of a hospital-grade x-ray tube, a rotary phantom holder, a CMOS detector and a grating system. Phantom studies are being carried out to optimize and characterize this system. We also developed new image acquisition scheme, including moire pattern-based retrieval and source grating stepping, to improve the system towards practical applications.