New types of X-ray computed tomography (CT) with synchrotron radiation: fluorescent X-ray CT and phase-contrast X-ray CT using interferometer.

Abstract

New types of X-ray computed tomography (CT), fluorescent X-ray CT and phase-contrast X-ray CT are being developed for biomedical research. While fluorescent scanning X-ray CT (FXCT) can detect specific contrast elements, or endogenous iodine, at very low content (less than 400 pg iodine of tissue in a volume of 8 x 10(-6) ml), the phase-contrast X-ray CT (PCCT) is a highly sensitive imaging technique to differentiate between different biological tissue types (based on their specific gravity variation) without the use of a contrast agent. Therefore, we can expect functional diagnosis with FXCT, and high contrast, high resolution biological imaging with PCCT. In this paper, a human thyroid gland imaged by FXCT, and a metastatic human cancerous lesion depicted using PCCT are presented. The latter method used a newly manufactured, large, monolithic, X-ray interferometer, which is described in this paper in detail.