CdTe/CZT Detectors in Photon-Counting CT: The Enabling Technology Behind Spectral Imaging

Abstract

Photon-counting computed tomography (PCCT) employs CdTe/CZT semiconductor detectors that directly convert X-ray photons into electrical signals while simultaneously recording their energy. This technology eliminates scintillation, improves quantum efficiency, and enables native spectral imaging with ultra-high resolution (<0.25 mm). Quantum Iterative Reconstruction (QIR), specifically developed for PCCT, optimizes image quality by preserving natural tissue texture and ensuring spectral stability. Clinically, PCCT offers significant advantages in cardiology, thoracic/oncologic imaging, neuroimaging, musculoskeletal, and pediatric applications, with dose reductions of 20-40% compared to dual-energy CT. This review synthesizes CdTe/CZT detector physics, QIR reconstruction principles, and clinical applications, providing practical guidance for implementation and multidisciplinary management of PCCT technology.