Abstract: Objective To minimize of the radiation dose of cardiovascular CT angiography (CTA) imaging while preserving the
image quality. Methods To reduce the radiation dose in CTA imaging, the normal-dose scan induced non-local means
(ndiNLM) algorithm was adapted for low-mAs scanned CTA image restoration by using the previous scanned high-quality
image. Results Qualitative and quantitative evaluations were carried out on both simulated phantom and clinical CTA scans
in terms of accuracy and resolution properties. Compared to the original NLM algorithm, the ndiNLM method could achieve
noticeable gains in terms of noise-induced artifacts suppression and enhanced structure preservation. Conclusion The
ndiNLM algorithm is a potential useful technique to reduce the radiation dose in CTAimaging.