管电压100kV下双源CT冠状动脉成像的可行性

Feasibility of Dual-source CT Coronary Artery Angiography with 100 kV Tube Voltage

目的探讨双源CT100kV管电压冠状动脉成像的可行性。资料与方法60例行双源CT冠状动脉造影患者,体重指数<25.0kg/m2、心率<75次/min、窦性心律且规整,随机分成100kV、362mA及120kV、400mA两组,每组30例。比较两组的影像质量、平均CT值、图像噪声、信噪比及辐射剂量。结果双源CT冠状动脉造影显示两组影像质量评分分别为(3.50±0.61)分和(3.30±0.86)分,差异无统计学意义(P>0.05);100kV组平均CT值为(646.50±127.15)Hu,明显高于120kV组的(471.35±88.13)Hu(P<0.05);100kV组图像噪声高于120kV组(P<0.05),但两组信噪比差异无统计学意义(P>0.05);120kV、100kV组有效辐射剂量分别为(10.39±0.36)mSv和(7.29±0.36)mSv,差异有统计学意义(P<0.05)。结论对体重轻、心率不快而律齐者采用管电压100kV行冠状动脉CT血管造影,可在保证图像质量满足诊断的前提下减少辐射剂量。

Purpose To explore the feasibility of dual-source computed tomography coronary angiography（CTCA） at tube voltage of 100 kV.Materials and Methods Dual-source CTCA was performed in 60 consecutive patients with body mass index（BMI） lower than 25.0 kg/m 2 and heart rate less than 75 beats/min.60 cases were randomly divided into two groups.Thirty were examined with a standard protocol（120 kV/400 mA）,30 were examined at 100 kV/362 mA.The differences in image quality,mean CT values,image noise,signal-to-noise ratio and radiation dose between two groups were compared.Results The coronary artery image quality scores for group 120 kV and 100 kV were（3.50±0.61） and（3.30±0.86）,respectively.There was no statistical difference between the two groups（P 0.05）.The mean CT value in 100 kV group [（646.50±127.15） Hu] was statistically higher than 120 kV group [（471.35±88.13）（P0.05）.The image noise in 100 kV group was significantly higher than 120 kV group（P0.05）.The SNR in 100 kV group was higher than 120 kV group,but there was no statistical difference between the two groups（P0.05）.The effective radiation dose was（10.39±0.36） mSv for 120 kV group and（7.29±0.36） mSv for 100 kV group with statistical difference（P0.05）.Conclusion In patients with BMI25.0 kg/m 2,resting heart rate 75 beats/min and normal heart rhythm,CTCA at tube voltage of 100 kV can significantly reduce the radiation dose without reducing image quality.