Improved Image Quality in X-ray Fluorescence Computed Tomography by Combining Dual-Energy Scatter Correction and High-Sensitivity Multi-Pinhole Collimator

Our group is developing a pinhole X-ray fluorescence computed tomography (XFCT) system that enables acquisition of bio functional images using non-radioactive tracer agents (e.g. iodine compounds), but the image contrast is low due to scattered radiation from the subject. In addition, statistical noise is large due to the low sensitivity of single pinhole. In this study, we attempted to improve the contrast-to-noise ratio (CNR) of XFCT images by a new method that combines the dual-energy scattering correction (SC) method and high-sensitivity multi-pinhole. The results of physical phantom experiments using synchrotron radiation monochromatic X-rays showed that the CNR of reconstructed images was improved by a factor of 11 with SC, by a factor of 3.4 with multi-pinhole, and by a factor of 22 with both methods at a iodine solution of 0.3 mg/ml compared to single pinhole and No-SC. The combination of dual-energy SC and high-sensitivity multi-pinhole collimator greatly improved the image quality of XFCT images.