婴幼儿肾脏64排螺旋CT低剂量的扫描研究初探  

The study of infant renal scanning with low-dose by 64-slice spiral CT

作　　者：彭谦[1] 范淼[1] 孟悛非[1] 陈星[1] 

机构地区：[1]中山大学附属第一医院放射科,广州510080

出　　处：《影像诊断与介入放射学》2008年第5期215-218,共4页Diagnostic Imaging & Interventional Radiology

摘　　要：目的探讨婴幼儿肾脏64排螺旋CT低剂量扫描技术的可行性。方法应用东芝Aquilion64排螺旋CT机(multi-slice computed tomography,MSCT),选取婴幼儿肾脏扫描四期中的一期降低剂量,先行预实验。按照100mA、40mA、30mA、20mA、10mA分组。从①图像伪影;②质地(噪声);③肾脏结构的显示;④肾脏与周围组织的对比4个方面评价。图像不满足诊断要求(不合格)即不再进行更低剂量组扫描。根据预实验计算出样本量并进行实验,同时记录权重CT剂量指数(Weighted CT dose index,CTDIW),进行统计学分析。结果20mA以上组剂量基本可以满足临床诊断的需要。通过秩和检验,两两比较,其中仅20mA与10mA比较时P<0.0001。因而得出结论,在控制总的假阳性率不超过0.05的情况下,20mA以上组之间的图像质量评分差异无统计学意义,20mA与10mA的图像质量评分差异有统计学意义。20mA时的CTDIW较100mA时的CTDIW降低了80.7%。结论婴幼儿肾脏MSCT扫描时,我们获得的初步最低管电流为20mA。婴幼儿肾脏低剂量扫描的研究为降低应用于儿童检查的MSCT辐射剂量提供了借鉴。Objective To study the possibility of 64 slice spiral CT in the examination of the infant with low dosescanning. Methods Choosing one phase in infant renal CT scanning to decrease CT radiation dose with Toshiba aquilion 64-slice spiral CT. Made preliminary test at first. Divided into different mA groups （100mA, 40mA, 30mA, 20mA, 10mA）. To evaluate image quality from 4 parts： ①artfact ;②noise;③renai structure;④renal edge. Dose was not be decreased lower if the image couldn＇t gratify the diagnostic standard. Calculated sample size and did experiment on the basis of preliminary test. Recorded the weighted CT dose index （CTDIW） at the same time and made statistical analysis. Results The groups dose more than 20mA could satisfy clinical diagnostic standard. Through rank sum test among different dose groups, P〈 0.0001 only between 20mA and 10mA groups. We could arrive at results that no significant difference among the groups dose more than 20mA and significant difference between 20mA and 10mA groups. CTDIw decreased 80.7% when current decreased from 100mA to 20 mA. Conclusion The minimum mA we gained primarily was 20mA in the infant renal scanning with low-dose by 64-slice spiral CT. This investigation can decrease infant MSCT radiation dose and be referenced by the examinations in other infant organ.

关 键 词：婴幼儿 断层摄影术 X线计算机 低剂量 

分 类 号：R816.92[医药卫生—放射医学]