64排螺旋CT轴扫节段扫描对降低腹部CT检查辐射剂量的作用

Radiation dose reduction with cine segment technique in abdominal CT scan

目的研究轴扫节段扫描对降低腹部CT检查辐射剂量的作用。方法 54例患者按照就诊顺序分成3组,A组20例螺旋扫描,B组16例轴扫扫描,C组18例轴扫节段扫描,均使用120 kV,自动毫安,噪声指数=8,分别进行平扫和增强扫描,比较各组图像质量、噪声水平和平均辐射剂量。结果各组图像质量得分之间差异无统计学意义(P>0.05)。平扫3组图像噪声差异无统计学意义,增强后A组和B组图像噪声之间差异无统计学意义(P>0.05),C组和其他两组之间差异有统计学意义(P<0.01)。有效剂量C组比A组降低约47%,比B组降低约25%的,差异有统计学意义(P<0.01)。结论自动毫安技术和轴扫节段扫描能有效降低腹部CT扫描的辐射剂量,保证图像质量。

Objective To evaluate the value of low-dose multi-slice CT（MSCT） scanning with smart-mA and Cine Segment technique in radiation dose reduction in abdominal CT scan.Methods A total of 54 patients with abdominal CT scan were divided into three groups,Group A（Smart-mA scanning with 120 kV,n=20）,Group B（Smart-mA with Noise Index（NI） =8;Cine scanning with 120 kV;n=16） and Group C（Smart-mA,NI=8;Cine segment scanning with 120 kV;n=8）.Radiation dose,and quality score and noise of image were compared.Results There was no significant difference in image quality score among the 3 groups.Image noise in Group C was significant higher than those in the other 2 groups after contrast injection（P0.01）.However,significant reduction of radiation dose by 47% revealed in Group C when comparing with that in Group A;and by 25% when comparing with that in Group A（P0.01）.Conclusion Smart-mA and Cine Segment scanning techniques effectively reduce the radiation dose in abdominal CT scan.