Photon-counting CT in liver disease： applications and advances

Photon-counting computed tomography (PCCT) represents a significant technological breakthrough in the field of CT imaging in recent years. This innovative technology utilizes novel semiconductor detectors to directly detect and count individual X-ray photons, enabling high-precision multi-energy data acquisition. Compared with traditional energy-integrating detector CT (EID-CT), PCCT offers significant technical advantages, including ultra-high spatial resolution (with a minimum detector pixel size of 0.15×0.18 mm), improved contrast-to-noise ratio (CNR increase of 15%-45%), and substantial radiation dose reduction (20%-90%). Moreover, PCCT can generate standardized CT value images, ensu-ring stable and reproducible quantitative measurements suitable for tissue composition analysis. With its ability to acquire data across multiple energy bins, PCCT achieves true multi-energy spectral imaging. In liver diseases, PCCT enables non-enhanced quantification of hepatic fat and iron content, with 70 keV standardized CT values showing a strong correlation with MRI-derived proton density fat fraction (PDFF). During contrast-enhanced scans, PCCT significantly improves the detection rate and lesion margin delineation of hypovascular tumors and allows accurate enhancement quantification through iodine maps. Additionally, PCCT enables ultra-low-dose, one-stop imaging that simultaneously provides functional hemodynamic parameters of hepatic microcirculation and high-quality multiphasic monoenergetic CT images for clinical diagnosis and preoperative planning—without the need for additional contrast medium or supplementary triphasic scans. This dual benefit of low radiation and contrast dose supports its clinical utility in liver imaging. This review focuses on recent advances in the application of PCCT in the diagnosis and treatment of diffuse and neoplastic liver diseases, aiming to provide theoretical foundations and practical insights for its broader implementation in precision hepatology.