Attenuation
We have shown that lower limb CTA with half iodine-load SDCT at 40 keV yielded higher VA across all anatomical levels than full iodine-load conventional CTA. The control showed higher VA than 50 keV, but the effect size was small and the p-value borderline significant, and the difference was not significant in the multivariate analysis. Reported optimal VA is approximately 350 HU, while 200–250 HU is clinically acceptable [