摘要目的 评估64层螺旋cT自动管电流调节技术对婴幼儿头颅的图像质量和辐射剂量的影响.方法 按2.5、2.75、3.0和4.0的SD(标准差)值将200例婴幼儿随机分成4组,用自动管电流调节技术行头颅cT扫描,每组各50例,回顾性统计分析各组的图像质量和辐射剂量.结果 当SD为2.5、2.75、3.0和4.0时,CTDI_(vol)最高值分别为60、49.8、42.9和25.8 mGy,有效剂量分别为(3.27±1.01)、(2.78±0.85)、(2.40±0.74)和(1.49±0.45)mSv·mGy~(-1)·cm~(-1),各组比较差异均有统计学意义(F=48.99,P<0.05);图像质量优秀率分别为100%、96%、70%和20%,其中SD 2.5组新生儿12例,sD 2.75组新生儿(2例)的图像质量均为良,SD 3.0组图像质量良以下均为<1周岁的病例,sD 4.0组图像质量优均为>2岁6个月和头围较大的病例.结论 ATCM的个性化应用可实现婴幼儿头颅cT的图像质量、辐射剂量和诊断图像的最佳平衡,建议对新生儿、1个月～1周岁、l～3周岁和头围较大或复古病例分别采用2.5、2.75、3.0和4.0的sD值.

abstractsObjective To evaluate the effect of automatic tube current modulation on imaging qualitv and iesion revealed in infant brain.Methods The infant patients of 200 cases were divided into four groups according to the values of SD (2.5,2.75,3.0,4.0),50 cases in each group.They were perfbrmed with the automatic tube current modulation scanning in brain.The imaging quality and radiation dose were analyzed.Results When the values of SD were 2.5,2.75,3.0 and 4.0,the high values of CTDl_(vol) were 60.0,49.8,42.9 and 25.8 mGy,respectively.The effective doses were (3.27±1.01),(2.78±0.85),(2.40±0.74)and (1.491.45)mSv·mGy·~(-1)·cm~(-1),respectively.There wassignifieant difference among those groups (F=48.99,P<0.05).The excellent imaging qualities were 100%,96%,70%and 20%.12 cases were neonate in SD 2.5 group.In SD 2.75 group,the imaging quality of neonate (2 cases) were all fine.In SD 3.0 group,the imaging quality was not ideal for the ages less than 1 vear.In SD 4.0 group,when the infants aged over 2 years and 6 months,or with the larger head circumference.their imaging quality were all excellent.Conclusions The individual application of ATCM could obtain the best balance among imaging quality,radiation dose and diagnostic quality.The SD 2.5.2.75.3.0 and 4.0 might be suitable to infants of newborn,1 month to 1 year old,1 to 3 years,the larger head circumference and part of the reviewed cases.