The clinical research of low dose scanning protocol for aorto-iliac and lower extremity arteries CT angiography / 中华放射医学与防护杂志

ABSTRACT

Objective To study the feasibility of reducing radiation dose in aorto-iliac and lower extremity arteries CT angiography (CTA) with low tube voltage (100 kV) and automatic tube current modulation(ATCM).Methods Totally 61 patients requiting aorto-iliac and lower extremity arteries CTA for clinical reasons were prospectively enrolled in study.The patients were randomly assigned to 3 groupsGroup A(120 kV),Group B (100 kV) and Group C (100 kV with automatic tube current modulation).Both quantitative and qualitative analysis were included in this research.Group C was divided into obese group(BMI≥ 24.9 kg/m2) and normal group(BMI ＜ 24.9 kg/m2).The radiation doses were analyzed respectively among two groups.Results The subjective evaluations of image quality for axial,MIP and VR were good.There were no significant differences among group A,B and C in SNR and CNR (P ＞0.05).The effective dose of group A,B and C was 8.20 mSv,5.36 mSv,and was 7.48 mSv,respectively Group B was 34.6％ less than group A.Group C was 39.5％ more than group B,and there was no significant differences between group A and C (P ＞ 0.05).The effective dose of group C1 was 7.11mSv,group C2 was 9.69 mSv,the E with group C1 were significantly less than group C2 (t =-3.163,P ＜0.05),the effective dose of group C1 was 13.3％ less than group A (Z =-2.822,P ＜ 0.05),but the group C2 was more than group A (P ＞ 0.05) and group B (Z =-3.426,P ＜ 0.05).Conclusions Lowkilovoltage (100 kV) CT scanning protocol is feasible in multi-detector CT angiography for aortoiliac and lower extremity arteries.Automatic low tube voltage (100 kV) with automatic tube current modulation (ATCM) scanning protocol can be used for someone with BMI less than 24.9 kg/m2.