320排CT高管电压在低剂量扫描中的应用

Application of high tube voltage in low dose CT scan with 320-slice CT

目的探讨管电压对320排CT颅脑扫描辐射剂量及图像质量的相关影响,优化CT低剂量扫描参数。方法随机把60例颅脑平扫受检者分成3组,每组20例。分别以100 kV,400 mAs、120 kV,220 mAs和135 kV,160mAs进行扫描。记录不同管电压扫描的辐射剂量长度乘积(DLP),测量扫描所得图像中豆状核和丘脑区的CT值标准差,并由两位副主任医师对图像质量进行盲法评分,对比分析不同管电压CT扫描的辐射剂量及图像质量。结果 3组辐射剂量长度乘积(DLP)100kV组为601.7mGy,120kV组为551.0mGy,135kV组为533.8mGy,135kV组明显低于100kV组。3组图像质量差异无统计学意义(P>O.05),结论高管电压颅脑CT扫描,有助于降低扫描辐射剂量。

Objective To assess the influence of different tube voltage on image quality and scanning radiation does with 320-slices CT to optimize the low dose CT scan parameters. Methods 60 patients were devided into 3 groups randomly. Patients in group A, B and C received scanning with the tube voltage and tube current as 100 kV 400 mAs, 120 kV, 220 mAs, 135 kV and 160mAs, respectively. Radiation dose length product （DLP） was recorded and the standard deviation of CT value in lenticular nucleus and thalamus was acquired. The image quality with different scanning parameters was assessed by two associate chief physicians blindly. Results DLP of the three group was 601.7 mGy, 551.0 mGy and 533.8 mGy. DLP of group C was significantly lower than those of group A. And there is no no statistically significant differences （P〉0.05）on and the image quality among the groups. Conclusion High voltage CT scans can decrease the does of CT scan without lowering the image quality.