低浓度等渗对比剂碘克沙醇(270mg I/mL)联合低管电压在640层容积CT冠脉CTA检查中的可行性研究

Feasibility Research of Low Concentration Contrast Agent Iodixanol(270 mg I/mL)Combined with the Lower Tube Voltage in Coronary CTA with 640-slice Volumetric CT

目的探讨低管电压(100kV)结合低浓度等渗对比剂碘克沙醇(270mg I/mL)在640层动态容积CT冠脉CTA检查中的可行性。方法将临床拟行冠脉CTA检查的89例患者随机分成A、B组:A组44例,B组45例;A组低管电压120kV,对比剂为320 mg I/mL碘克沙醇;B组低管电压100kV,对比剂为270mg I/mL碘克沙醇。由2名心血管影像诊断医师对图像按5分法进行主观评价,同时按15段法测量冠脉的CT值和背景噪声,计算对比噪声比(CNR)和信噪比(SNR),以此来进行客观评价,并比较2组的有效辐射剂量。结果 A组主动脉根部CT值明显高于B组,但2组CT值均高于250 HU,因此能够满足诊断需要;B组其余各节段血管腔CT值均高于A组;比较A组与B组的主动脉根部SNR值、CNR值,差异有统计学意义(P<0.05);比较2组其余血管各节段的SNR值、CNR值,差异无统计学意义(P>0.05)。有效辐射剂量B组较A组显著降低,差异有统计学意义(P<0.05)。结论在640层容积CT冠脉CTA检查中,使用碘克沙醇(270mg I/mL)并结合低管电压(100kV),可得到能够满足诊断需求的高质量图像,显著降低辐射剂量和对比剂肾病的风险,可行性较好。

To evluate the feasibility of the lower tube voltage combined with low concentration contrast agent iodixanol(270 mg I/mL)in coronary CTA with 640-slice volumetric CT.Methods 89 patients receiving coronary CTA examination were randomly divided into two groups.Group A(44 cases)received iodixanol(320 mgI/mL)combined with 120 kV,while group B(45 cases)received iodixanol(270 mg I/mL)combined with 100 kV.Subjective evaluation was done by two experienced doctors of cardiovascular imaging diagnosis by five-point method.CT value,image noise,CNR,SNR and effective radiation dose were calculated to do objective evaluation.Results The CT value of aortic root in group A was significantly higher than that in group B,but the CT value in both groups were higher than 250 HU,which could meet the diagnostic requirements;The CT value of rest each vascular segment in group B was higher than those in group A;CNR and SNR of aortic root in two groups were of statistically significant difference(P<0.05),while CNR and SNR of the rest each vascular segment in two groups were of no statistically significant difference(P>0.05);effective radiation dose in group B was significantly lower than that in group A,and the difference was statistically significant(P<0.05).Conclusion In coronary CTA with 640-slice volumetric CT,the application of iodixanol(270 mg I/mL)combined with the lower tuber voltage can get a better image quality that could meet the diagnostic requirements,reduce the risk of CIN,and significantly lower the radiation dose at the same time,so the feasibility is better.