Abstract: Objective The aim of the research was to compare the radiation dose and image quality of abdominal aorta and lower extremity artery CTA under 80kV and 120kV，to evaluate the feasibility of low tube voltage abdominal aorta and lower extremity artery CTA. Methods It was a retrospective research, there were 34 patients who were divided into two groups with 80kV or 120kV tuber voltage separately received abdominal aorta and lower extremity CTA. The objective and subjective evaluations were done based on axial and 3D reconstruction images. The data was analyzed by Shapiro-WilkNormal distribution test and independent t test. Results The CT number of arteries under 80kV tube voltage was between 542HU to 601HU, which were much higher than that under 120kV tube voltage. There were no statistical difference between CNR and objective evaluation between the two groups. The DLP of group A with 80kV tube voltage was 205.94±20.69 mGy·cm, and which was 775.47±82.85 mGy·cm of group B with 120kV tube voltage. The DLP decreased 73%. Conclusion The image quality of abdominal aorta and lower extremity artery CTA under 80kV tube voltage with ATCM could meet the need of clinical diagnose.

Key words: abdominal aorta, lower extremity atery, CTA, tube voltage, ATCM