Article ID: 25-00045
Objectives : To validate virtual non-contrast (VNC) imaging accuracy and related dual-energy CT (DECT) metrics (CT, CM, and iodine density values) under varied iodine concentrations and flow rates using a phantom model.
Methods : Iodine solutions (3.7-18.5 mg I/mL) were circulated through a phantom at five flow rates (120-500 mL/min). DECT scanning (SOMATOM go.Top) was performed three times per condition. Four metrics were measured from ROIs on ten central slices per scan (n = 3 per condition ; N = 75). Two-way ANOVA and Tukey’s HSD test were applied (α = 0.05).
Results : Iodine concentration was the predominant determinant for all metrics (p < .001). VNC values showed a consistent negative deviation that increased with concentration and high variability across conditions. A significant interaction between concentration and flow rate was observed for iodine density (p = .019), indicating that flow dynamics affect material decomposition. CT, CM, and iodine density values showed stable, predictable responses.
Conclusion : VNC accuracy is compromised at high iodine concentrations, with flow-related disturbances introducing additional instability via material decomposition errors. Flow dynamics should be considered when interpreting VNC imaging, particularly in arterial-phase CTA.
