多排CT低剂量不同扫描方法在新生儿颅脑检查中应用

Study on the decrease in scanning radiation of 64 Row of Spiral CT in the Skull & brain of newborn

目的探讨多排CT低剂量不同扫描方法在新生儿颅脑检查中的应用,用最佳的检查方法,最小辐射剂量,减少辐射损害。方法用螺旋和横断两种不同扫描方式,采用逐渐降低扫描参数方法,得出新生儿颅脑多排CT扫描可用的最佳方法和最低扫描参数。固定KVP值120KV和其他扫描参数,每次降低10mAs。横断法低剂量组扫描参数从120KVP.60mAs开始,螺旋法低剂量组扫描参数从120KV.90mAs开始。每组扫描20例患儿,每组扫描所得图像由二位高级职称影像诊断专家按图像清晰度、脑组织层次对比度、脑室、脑沟解剖结构及病变显示能力,将图像质量分为优质、良好、一般、较差、差5个等级,分别被评为5,4,3,2,1分,3分及以上的图像认为满足诊断要求。结果多排CT螺旋扫描120KVP.70mAs是可用的最低扫描参数;横断扫描120KV.40mAs是可用最低参数。两组最低扫描参数辐射剂量分别是常规螺旋扫描120KVP.150mAs的47%和横断常规的40%。同时低剂量横断扫描是螺旋扫描剂量的31%。结论多排螺旋CT新生儿颅脑扫描的最佳方法是横断扫描,可用的最低扫描参数120KV.40mAs。

Objective Study the lowest parameter of scanning radiation in 64Row of Spiral CT used in Skull&brain of newborn,aiming to decrease radiation.Methods To find the best method and the lowest parameter used in Skull&brain of newborn,spiral scanning and section scanning were used by gradually decreasing scanning parameter.KVP was fixed at 120KV,other scanning parameter were gradually decreased by 10mAs.low dose group of section scanning began from 120KV.60mAs,low dose group of spiral scanning began from120KV.90mAs.20newborn were scanned at each group,images of each group were by three image diagnosis expert with senior title,according to image definition,gradation and contrast,concrete anatomy structure in brain tissue,ventricle,sulcus as well as detectabilities of lesions,divided into five levels,named as high,good,general,poor,worse quality.,scored 5,4,3,2,1respectively.3and above 3were thought as qualified.Results 120KVP.70mAs is the lowest scanning parameter accesable in 64Row of Spiral CT.120KVP.30mAs is the lowest scanning parameter accesable in section scanning. cmin section scanning.the scanning parameter of two group is 47%and 40%to general scanning respectively.Theparameter in section scanning is 31%to that of spiral scanning.Accordingly,.Conclusion The best method in 64Row of Spiral CT used in skull& brain of newborn is section scanning.the lowest scanning parameter is 120KV.40mAs