Synchrotron radiation used fluorescent x-ray computed tomography as a novel molecular imaging

Fluorescent x-ray computed tomography (FXCT) can detect and image a trace of non-radioactive imaging agent, e.g., iodine, in a biomedical subject at a high spatial resolution, so it can be a novel molecular imaging modality. Presently, we are developing an FXCT system using synchrotron radiation as an x-ray source for in-vivo imaging brains of small animals such as mouse, rat, and so on. We must overcome the following two difficulties damaging an image-quality: One difficulty is that the number of projections is remarkably restricted due to the long data-acquisition time. In order to reduce the measurement time, we propose to eliminate unnecessary beam scans by adaptively and efficiently controlling the scan according to the subject size. The other difficulty is that the measured data are contaminated by inevitable physical factors. Here, we propose data-processing methods to estimate reliable projections from raw data. The efficacies of the proposed methods are demonstrated using physical-phantom images and an in-vivo image of mouse brain, which were reconstructed from experimental data acquired in KEK, Japan.