Scintillator–single-photon avalanche diode array-based energy resolving photon counting X-ray detector

Abstract X-ray photon counting computed tomography (PCCT) has garnered considerable interest owing to its low dose administration, high-quality imaging, and material decomposition characteristics. Current commercial PCCT systems employ compound semiconductor photon counting X-ray detectors, which offer good energy resolution. However, the choice of materials is limited, and cadmium telluride or cadmium zinc telluride is mostly used. Although indirect radiation detectors can be used as alternatives to compound semiconductor detectors, implementing fine-pitch segmentation in such detectors is challenging. In the present study, we designed an indirect fine-pitch X-ray photon counting detector by combining miniaturized silicon photomultiplier arrays and fast scintillation crystals, with a pixel size of 250 µm, for PCCT. Performance characterization of the fabricated detector reveals its potential to discriminate photon energies with a reasonable resolution, good spatial resolution, charge-sharing inhibition ability.