【摘要】 目的探讨高流速稀释对比剂在低管电压冠状动脉成像中的可行性及对图像质量的影响。方法收集120例疑似冠心病患者行冠状动脉CTA检查,按照随机数字表法等分为A、B、C三组各40例。A组以4.8ml/s直接注射碘普罗胺(300mg I/ml),之后按相同速率追加注射生理盐水36ml,B、C两组以6ml/s注射稀释对比剂,其浓度为使用双流技术按对比剂与生理盐水8:2实时配比为240mg/ml,两组按相同速率追加注射生理盐水45ml。A、B、C三组对比剂用量分别为0.8ml/kg、1ml/kg、0.8ml/kg,三组所得扫描数据均使用迭代算法(AIDR 3D)重建图像,扫描管电压设置分别为100k V、100k V、80k V。比较三组之间升主动脉、降主动脉、左冠状动脉主干、左前降支近段、左回旋支近段及右冠状动脉近段平均强化CT值(SI)、噪声(SD)、对比噪声比(CNR)、信噪比(SNR)有效辐射剂量(E)及冠状动脉图像质量评分。结果三组年龄、心率、管电流、体质指数(BMI)、体重、身高均无统计学差异(P>0.017),A组与B、C两组注射压力有统计学差异(P<0.017),B组与A、C两组对比剂注射用量有统计学差异(P<0.017),C组与A、B两组间注射时间、总碘含量、辐射剂量(ED)有统计学差异(P<0.017)。三组间总节段质量得分及各大段平均质量得分均无统计学差异(P>0.05)。A、C两组升主动脉、右冠状动脉近段血管强化值及右冠状动脉、左冠状动脉主干、左前降支近段噪声有统计学差异(P<0.017),B、C两组升主动脉血管强化值、右冠状动脉及左回旋支近段噪声有统计学差异(P<0.017)。三组之间胸主动脉及各冠状动脉血管近段SNR、CNR无统计学意义(P>0.05)。结论使用6ml/s的高流速240mg/ml稀释对比剂在低管电压冠状动脉CTA中可以满足诊断需求并且不降低图像质量。更多还原

【Abstract】 Objective To evaluate the feasibility of low iodine mix contrast medium on vascular enhancement,image quality and radiation dose of coronary CT angiography( CCTA) using injected with high flow rates and low-tube-voltage technique. Methods One hundred and twenty consecutive patients with BMIs < 25 kg/m2 were scanned on Toshiba Aquilion one 640 scanner.They were randomly divided into three groups with 40 cases in each,Group A( n = 40) received the standard injection protocol:Iopromide 300 mg/ml; flow rate: 4. 8 ml/s,followed by a saline chaser with 36 ml. Group B( n = 40) and group C( n = 40) received mix contrast media of 240 mg/ml using double injection technology by high pressure injector. The mix contrast agent was composed of 80% Iopromide and 20% saline; at an injection rate of 6 ml/s,followed by a saline chaser with 45 ml. Three groups of iodine delivery rate( IDR,1. 44 g/s) were kept identical. Three groups of contrast agent were 0. 8 ml/kg,1 ml/kg,0. 8 ml/kg. Three groups of the scan data were used iterative reconstruction technique( AIDR 3 D),scanning tube voltage settings were100 k V,100 k V,80 k V. CT attenuation of the main proximal vessels( aorta ascendens,aorta descendens,RCA,LM,LAD,LCX) was measured and objective image quality( SD,CNR,SNR) was estimated. Subjective evaluation was assessed by an experienced radiologist. Results There was significant difference in amount of contrast media injected between the three groups( P< 0. 05). And the injection time,total iodine load,radiation dose( ED) had no significant difference between group A and group B( P > 0. 05). There was significant difference in injection time,total iodine load,radiation dose( ED) between group B and group C( P < 0. 05). There was no significant difference in the total segment quality score and major average quality scores between the three groups( P > 0. 05). There was no significant difference in CT attenuation of the main proximal vessels( aorta ascendens,aorta descendens,RCA,LM,LAD,LCX,P > 0. 05). There was significant differences in SD of coronary between three groups( P < 0. 017). No significant differences were found in SNR,CNR of thoracic aorta and all proximal coronary between three groups( P > 0. 017). Conclusion Usage of low iodine mix contrast media( 240 mg/ml) and injection with high flow rates( 6 ml/s) are feasible. No significant differences in image quality are found be comparable to Iopromide( 300 mg/ml).更多还原