Silicon-based Photon Counting Computed Tomography for Advanced Cardiac Imaging

簡要摘要

Computed tomography (CT) is a key imaging modality, with rapidly increasing use in cardiovascular diagnostics. Coronary CT angiography (CCTA) provides high-resolution, non-invasive assessment of coronary anatomy and is now recommended as a first-line test for suspected coronary artery disease (CAD) due to its excellent sensitivity, allowing for the firm exclusion of the disease. CCTA, accompanied by coronary artery calcium (CAC) scanning have become, therefore, recommended as the first-line diagnostic modalities in a majority of patients with suspected CAD. It is thanks to the steady efforts to improve this modality's diagnostic performance further and reduce patients' exposure to radiation and contrast agents that have contributed to the successful implementation of this modality in routine clinical practice. However, further progress with conventional energy-integrating detector (EID) CT is limited by detector physics, as EIDs measure only total deposited x-ray energy. By contrast, photon-counting CT (PCCT) introduces semiconductor detectors that register individual photons and their energies, enabling higher spatial resolution, improved contrast-to-noise, and intrinsic spectral imaging. Early PCCT systems have shown better visualization of small coronary structures and reduced blooming, though limitations such as degraded energy resolution at high speeds and cross-talk still restrict full spectral performance. Radiation dose reductions are possible but have not yet been consistently achieved compared with optimized EID-CCTA, which is critical if PCCT is to be used for risk stratification or screening. There remains a need to better exploit PCCT's spectral capabilities for plaque and stent evaluation while maintaining acceptable radiation and contrast exposure. By 2026, second-generation silicon-based scanners (Si-PCCT) are approaching, offering potential improvements over first-generation cadmium-telluride systems. The present study aims to evaluate the diagnostic performance of such devices and exploit their technical advantages to lower radiation dose.