新生儿颅脑低剂量CT扫描参数研究  

The Study of Low-dose CT Scanning Technical Parameters in Neonate Brain

作　　者：吴爱琴[1] 郑文龙[2] 许崇永[1] 程建敏[1] 陈宇[1] 陈廷港[1] 

机构地区：[1]温州医学院育英儿童医院放射科,浙江温州325027 [2]温州市第二人民医院放射科

出　　处：《实用放射学杂志》2007年第1期97-99,共3页Journal of Practical Radiology

基　　金：温州市科技局基金资金项目(基金号:Y2004A067)。

摘　　要：目的探讨新生儿颅脑低剂量CT扫描的最佳参数,降低扫描辐射剂量。方法选取颅脑CT检查的新生儿150例,随机等分成5组。扫描参数:管电压120kV,层厚、层间距6mm,管电流分别使用250、200、150、100、50mAs行全颅脑CT扫描,统一于左基底节层面测量各组CT值及标准差(SD)。对5组剂量扫描的CT剂量加权指数(CTDIw)、全头颅扫描剂量长度乘积(DLP)、噪声及图像质量对比分析。结果(1)随着扫描剂量的降低,CTDIw(mGy)及DLP值明显下降,50mAs组仅为常规剂量组的20%;(2)50mAs组扫描图像质量等级以较好和一般为主,100mAs及以上各组以好、较好为主,mAs降低,图像质量也下降;(3)50mAs组图像噪声较大,但颅内正常结构及病变组织显示尚清,且可通过调整窗宽和窗位,使图像质量得到提高,基本不影响诊断。结论50mAs低剂量新生儿颅脑扫描的图像质量有所下降,但不影响诊断,且由于辐射剂量显著降低,有效地保护了新生儿。Objective To investigate the optimal technical parameters of low - dose CT scanning in neonate brain so that to reduce the radiation dose. Methods 150 neonates undergone CT scanning of head were randomly divided into five groups averagely. The technical pa- rameters included ： tube voltage 120 kV, slice thickness and gap 6 ram,tube current 250,200,150,100 and 50 mAs respectively for scanning the whole brain. The CT value of ROI and standard deviation （ SD ） were measured in the region of left basal nucleus. The weighted CT dose index （ CTDIw ） , dose length product （ DLP ） , noise and imaging quality were blindly evaluated in five different dose groups. Results （ 1 ） With the scanning dose reduced, CTDIw and DLP were evidently reduced, the 50 mAs group was only 20% of the conventional dose group ; （2） The imaging quality in 50 mAs group was better and general in majority,in 100 mAs and above groups was good and better in majority. The imaging quality decreased with mAs reduced ; （3）The imaging noise in 50 mAs group was heavy, but it could still demonstrate intracranial normal structure and lesion. The imaging quality could be improved through adjusting the window width and window level, and it did not influence the diagnosis on the whole. Conclusion The imaging quality using 50 mAs during CT scanning of head in neonate is certainly decreased, but do not influence the diagnosis and can protect newborns effectively undergone high radiation dose.

关 键 词：脑 新生儿 辐射剂量 扫描参数 体层摄影术 X线计算机 

分 类 号：R816.1[医药卫生—放射医学] R814.42[医药卫生—临床医学]