Photon-counting X-ray Computed Tomography Using a Cadmium Telluride Flat Panel Detector with High Spatial Resolutions and Dual-energy Selection

Abstract

Introduction: To perform energy-dispersive X-ray imaging, we constructed a photon-counting X-ray computed tomography (CT) scanner to perform enhanced K-edge CT. Methods: X-ray photons penetrating through an object were detected using a cadmium telluride flat panel detector (FPD) with pixel dimensions of 100 × 100 mm2, and 720 radiograms from the FPD were sent to the personal computer to reconstruct tomograms. Gadolinium (Gd) K-edge energy is 50.2 keV, and Gd-Kedge CT was carried out using photons with an energy range of 50–100 keV. Results: Compared with low-energy CT of 15–50 keV, the gray density of muscle and bone substantially decreased, and the image contrast of Gd media was improved utilizing Gd-K-edge CT. Conclusion: Using the cone beam, the effective pixel dimensions were 80 × 80 μm2, and blood vessels were observed at a high contrast using Gd-Kedge CT.

Keywords

• cadmium telluride flat panel detector
• dual-energy selection
• gadolinium-k-edge computed tomography
• high spatial resolution
• photon-counting computed tomography
• threshold energy