低浓度对比剂大螺距前门控双源CT冠状动脉成像初步研究  

Preliminary study of low concentration contrast material for high-pitch dual-source CT coronary angiography

作　　者：武永杰[1] 赵宏亮[1] 魏梦绮[1] 刘莹[1] 石明国[1] 宦怡[1] 郑敏文[1] 

机构地区：[1]第四军医大学西京医院放射科,陕西710032

出　　处：《放射学实践》2015年第5期554-559,共6页Radiologic Practice

基　　金：陕西省社会发展攻关课题(2013K12-20-03)

摘　　要：目的:评价低浓度对比剂Flash双源CT大螺距冠状动脉成像联合应用低kV和迭代重建算法对血管强化程度、图像质量和辐射剂量的影响。方法:对120例体重指数(BMI)<25kg/m2、心率≤65次/分且稳定的患者进行前瞻性心电触发大螺距双源CT冠状动脉扫描,检查者随机分成低浓度对比剂组(A组,60例)和高浓度对比剂组(B组,60例)。A组对比剂使用碘克沙醇(浓度为270mg I/mL),管电压为80kV,图像重建采用迭代重建算法(SAFIRE);B组对比剂使用碘普罗胺(浓度为370mg I/mL),管电压为100kV,图像重建采用滤波反投影算法(FBP)。两组图像均测量左右冠状动脉开口处、升主动脉根部及心底层面的胸主动脉CT值,并比较两组图像的噪声、信噪比(SNR)、对比噪声比(CNR)、主观图像质量评分和有效辐射剂量。结果:碘克沙醇270组各解剖部位平均强化CT值均明显高于碘普罗胺370组,差异均具有统计学意义(P<0.05)。碘克沙醇270组图像噪声、SNR、CNR较碘普罗胺370组略高,但差异均无统计学意义(P>0.05)。两组主观图像质量评分分别为(1.62±0.69)和(1.51±0.65),差异克统计学意义(P>0.05)。碘克沙醇270组有效辐射剂量较碘普罗胺370组明显降低[分别为(0.25±0.05)mSv和(0.55±0.11)mSv,P<0.001],低浓度组辐射剂量较高浓度组降低了54.5%。结论:当联合应用低kV和迭代重建算法时,即使使用低浓度对比剂(270mg I/mL)进行Flash双源CT大螺距冠状动脉成像,依然可以提高血管的对比强化效果且不降低图像质量,还能大幅度降低有效辐射剂量。Objective：To assess the impact of low concentration contrast medium with FLASH dual source high-pitch CT coronary angiography in combination with low kV and iterative reconstruction on the vascular enhancement,image quali- ty and radiation dosage, Methods： 120 patients with BMI〈25kg/m2 , heart beat≤65/m stably were recruited in this study. ECG-triggered high-pitch spiral acquisition dual-source CT coronary angiography was performed prospectively. Patients were randomly divided into a low contrast medium concentration group （group A） and high concentration group （Group B） with 60 patients for each group. Iodixanol 270 （270mg I/mL） were injected and low tube output （80kV） were used in Group A,images were reconstructed using iterative reconstruction technique （SAFIRE）. Iopromide 370 （370mg I/mL） and 100kV tube output were used in Group B,images were reconstructed using filtered back projection （FBP）. CT values were measured at the orifice of left and right coronary artery,root of ascending aorta and base of heart. Image quality was scored subjectively,the noise, SNR,CNR and effective radiation dose of the two groups were compared. Results：The mean CT val- ues after enhancement achieved at different anatomic sites of Group A was obviously higher than that of Group B,with sta- tistical difference （P〈0.05）. The image noise,SNR and CNR of Group A were slightly higher than that of Group B, with no statistic difference （P〉0.05）. The subjective score of image quality of the two groups was （1. 62±0.69） and （1.51± 0.65） respectively, with no statistic difference （P〉0.05）. The effective radiation dose was （0.25±0.05） roSy in Group A, which was markedly lower than that of Group B, （0.55 ±0.11 ） roSy, with significant statistic difference （P〉0.001 ）, with the reduction of dosage as 54.5%. Conclusions： The results demonstrated that with FLASH dual-source high-pitch spiral acquisition mode in combination with iterative reconstruction and low tube

关 键 词：冠状动脉 对比剂 体层摄影术 X线计算机 图像处理 计算机辅助 

分 类 号：R541.4[医药卫生—心血管疾病] R814.42[医药卫生—内科学]