Speaker
Description
Photon-counting computed tomography (PCCT) is a next-generation medical imaging technology that acquires spectral information by counting individual X-ray photons using energy thresholds. Current commercial PCCT systems use semiconductor detectors such as CdTe and CZT. Although, these detectors provide high energy resolution, they are limited by high cost and a lack of material flexibility. Additionally, charge-sharing effects significantly degrade the accuracy of spectral information. To overcome these limitations, we developed a 1D-64ch PCCT system incorporating a fast ceramic scintillator and a silicon photomultiplier (SiPM), and successfully demonstrated its usability through phantom experiments and in vivo imaging of mice injected with contrast agents.
However, acquiring 3D images with a 1D sensor is complex and time-consuming. As the next step toward clinical application, it is therefore essential to demonstrate the feasibility of a 2D, large-area sensor. The implementation of a 2D sensor is expected to significantly reduce imaging time and facilitate dynamic imaging. In this study, we developed a new PCCT system incorporating a 2D, large-area sensor array and a newly developed, high-performance ASIC, which was specifically designed for scintillator-based PCCT by Hamamatsu Photonics. This ASIC is compatible with various scintillators and MPPC specifications. As a result of optimization, it achieved higher energy resolution (~33% FWHM at 59.5 keV) and more than twice the count-rate tolerance (>10 Mcps/ch) compared to our previous system. Furthermore, we successfully obtained 3D K-edge images of three contrast agents using six energy threshold images, demonstrating the system’s capability to accurately acquire spectral information.
In this presentation, we will report on the performance evaluation and imaging results of the newly developed PCCT system.
