Lumen imaging in calcified coronary arteries using high-resolution Gd-enhanced color K-edge imaging with spectral photon-counting CT: a phantom study

OBJECTIVE: Conventional coronary computed tomography angiography (CCTA) lumen assessment is hampered by the similar attenuation of iodine and calcium. We assessed the lumen for Gd-enhanced CCTA on high-resolution color Gd K-edge imaging using a clinical spectral photon-counting computed tomography (SPCCT) prototype in an anthropomorphic phantom. MATERIALS AND METHODS: ), and spectral results were compared to conventional acquisition. Largest underestimation (-26%) and overestimation (16%) were shown for the high- and low-density calcification in comparison to physical size, respectively. CONCLUSION: Color Gd K-edge imaging with Gd-enhanced CCTA outperformed conventional imaging in assessing the coronary lumen in both noncalcified and calcified vessels, whilst accuracy depends on the presence and density of calcifications. RELEVANCE STATEMENT: In a phantom study, high-resolution color Gd K-edge imaging targeting Gd enabled accurate visualization of the coronary lumen in both calcified and noncalcified arteries, outperforming conventional CT angiography. In the presence of calcifications, only color Gd K-edge imaging provided objective lumen assessment, with accuracy influenced by calcium extent and density. KEY POINTS: Color Gd K-edge Gd-enhanced CCTA using SPCCT is feasible in a coronary artery phantom. Color Gd K-edge imaging improves lumen assessment in calcified vessels. Color Gd K-edge imaging potentially enhances diagnostic precision and treatment planning for patients with coronary artery disease.