Double Flash扫描方式在冠状动脉计算机断层扫描中的应用

Value of Double Flash scanning in coronary computerized tomography angiography

目的探讨双源计算机断层扫描(computerized tomography,CT)大螺距前瞻性心电触发采集模式(Flash模式)在冠状动脉CT中的应用价值。方法随访中国人民解放军总医院行冠状动脉CT检查的患者120例,其中采用Double Flash扫描方式组60例(A组),常规螺旋扫描方式组60例(B组)。入选患者在CT检查过程中心率均<70次/min,窦性心律且节律整齐,且体质量<100 kg。采用4分法对图像质量进行评价(1分为图像质量极好,2分为图像质量好,3分为图像质量一般,4分为图像质量差),并记录两组患者整个扫描过程中的总有效剂量值及总剂量长度乘积。结果两组间图像质量评分比较,差异无统计学意义(P>0.05)。A组整个扫描过程中的总有效剂量值明显低于B组,差异有统计学意义[(2.6±0.8)mSv vs.(8.6±1.3)mSv,P<0.05];总剂量长度乘积也明显低于B组,差异有统计学意义[(145.8±13.5)mGy·cm vs.(621.4±129.8)mGy·cm,P<0.05]。结论双源CT大螺距前瞻性心电触发采集模式应用于心率<70次/min的患者时与常规螺旋扫描模式比较,在保证图像质量的同时,还可显著降低辐射剂量。

Objectives To explore the value of double prospectively ECG-triggered high-pitch spiral acquisition （Double Flash） for coronary computerized tomography （CT） angiography.Methods Totally 120 patients who received coronary artery CT examination in Chinese People＇s Liberation Army General Hospital were followed up.They were divided into group A and group B according to different scan modes.Group A was given Double Flash scanning and group B was given Spiral scanning.All the patients were with heart rate below 70 beats per minute,sinus rhythm and body weight below 100 kg.The image quality was evaluated by 4 point scale （1 =excellent,2=good,3 =normal,4=poor or non-diagnostic）.The total effective dose equivalent and total dose length product of the two groups were recorded respectively.Results The two groups had no statistical significance in image quality score （P〉0.05）.The total effective dose [（2.6±0.8） mSv vs.（8.6±1.3） mSv,P〈0.05] and total dose length product [（145.8±13.5） mGy·cm vs.（621.4±129.8） mGy·cm,P〈0.05]of the entire scan process were significantly lower in group A than in group B （P〈0.05）.Conclusions It is clinically feasible to use flash dual-source spiral acquisition for coronary CT angiography in patients with heart rate below 70 beats per minute.This new process can substantially reduce the radiation dose while preserving good imaging quality.