不同对比剂用量方案在双源CT冠状动脉成像及心脏结构显示方面的研究

目的:选择适宜的对比剂用量,改善双源CT冠状动脉成像时对心脏结构的显示能力。方法:160例接受Defini-tion第一代双源CT冠脉CTA检查的患者随机分为4组,对比剂用量分别为:A组=采集时间×注射流速(X ml),B组=(X+5)ml,C组=(X+10)ml,D组=X+(15～20)]ml。各组均采用碘海醇(350mgI/ml),体质量<75kg者注射流率为4.8～5.0ml/s;体质量≥75kg者注射流率为5.5ml/s。应用Circulation分析软件,采用双盲法评价图像质量。分别测量各组冠状动脉各段、左右心室CT值,观察并记录对比剂伪影及严重程度、对比剂混合液是否均匀、室间隔显示是否清晰等。采用单因素方差分析法(One-way ANOVA)比较组间CT值、图像质量评分等有无差异,采用χ2检验比较室间隔等结构显示情况及对比剂伪影等。结果:各组间一般情况、质量评分、冠脉各段和左心室CT值等差异无统计学意义(P均>0.05)。右心室腔内CT值A、B、C、D组分别为(142.1±35.5)HU、(144.4±43.5)HU、(186.1±66.1)HU、(223.3±119.3)HU,C组与A、B、D组间差异均有统计学意义。各组室间隔尚能分辨(2分)的例数差异无统计学意义,但C、D组显示清晰(3分)的例数多于A、B组;C组条状伪影少于D组。综合分析,C组对比剂方案优于其他组。结论:本研究采用个性化的对比剂方案,对比剂用量=扫描采集时间×流率+10ml,结合患者体质量和体质量指数(BMI)计算对比剂注射流率,可以获得良好的冠脉CTA图像及较为满意的心脏结构、肺动脉显示效果,有一定临床应用价值。

Different contrast medium protocols in dual-source CT coronary artery angiography and cardiac structure research

Objective： To Select the appropriate contrast medium volume in order to improve the capabilities of cardiac structure display in dual source CT coronary angiography. Methods： One hundred and sixty patients undergoing dual source CT coronary angiography examination were randomly divided into 4 groups,contrast medium volume were as the following：group A= acqui sition time（AT） · injection flow rate（R）=X ml,group B= （X＋5）ml,group C= （X＋10）ml and group D X＋（15-20）]ml. All groups were using iohexol（350 mgI/ml） ,the injection rates were（4.8-5）ml/s（weight〈75 kg）and 5.5 ml/s（weight〉75 kg）. Image quality was evaluated by using circulation analysis software in double blind method. Attenuation was measured in the cor- onary artery segments, left ventricle, right ventrieular and others. Observed and recorded the degree of streak artifacts, the visu alization of right and left heart structures. Using one-way analysis of variance compared CT values and image quality scores, u- sing person Chi Square compared the visualization of interventricular septum and contrast artifact. Taking P〈 0.05 as the difference was statistically significant. Results：Among all the groups in general, quality scores, coronary segments and left ven tricular CT values had no significant difference（Pall〉0.05）. The attenuation of right ventricular cavity from group A to group Dwas（142.1±35.5）,（144.4±43. g）,（186.1±66.1）,（223.3±119.3）HU respectively. There were significant difference a- mong group C and group A, B, D. The cases of ventricular septurn showed better（2 score）were not significantly different among the groups,but the showed clear cases（3 score）in group C and D were more than that in group A and B. Streak artifacts in group C were less than that in group D. In summary, the contrast medium protocol in Group C was better than the other groups. Conclusions： This study used personalized contrast medium protocols, contrast medium volume= AT · R＋10 ml, combi ning with body weight and BMI calculation of injection rate, could ogtain satisfactory coronary CTA image, provide higher atten- uation of RV,get clear visualization of cardiac structure and pulmonary artery,has certain clinical application value.