摘要
目的:探讨在线动态剂量调节(D-DOM)扫描技术在儿童腹上区CT检查中的应用价值。方法:选取行腹上区CT扫描的患儿100例,研究组和对照组各50例,研究组使用D-DOM技术,对照组不使用D-DOM技术。记录两组病例扫描时机器自动显示的剂量长度乘积(DLP),并计算有效剂量(ED)值,同时记录研究组每例患者扫描图像上每层的mAs值。两组每例均取肝顶部、肝门及肝底部各1帧图像(共300帧),由两位副主任医师采用盲法评价图像质量,测量上述相同层面图像噪声并进行统计学处理。结果:研究组比对照组mAs最大下降54.00,平均下降18.46,两组间差异有统计学意义(P<0.05);图像质量主观评价,研究组肝顶部层面优良率为100%,略高于对照组(98.00%),肝门部两组病例优良率均为100%,但对照组优级片(78%)高于研究组(46%);肝底部两组病例优良率均为100%;研究组图像噪声平均值为3.6±1.1,对照组为3.4±1.0,两组病例图像噪声比较差异无统计学意义(t=0.477,P>0.05)。结论:儿童患者腹上区CT检查使用D-DOM技术进行实时在线mAs调节,既可以提高射线的利用效率从而降低辐射剂量,又能保证图像质量,具有一定的实际应用价值。
Objective：To investigate the value of D-DOM technique in upper abdominal CT examination of children.Methods：100 cases of children in upper abdominal CT examination were included in the study and equally divided into the study group and the contrast group.D-DOM technique was used in the study group while in the contrast group it was not.Dose length product（DLP） automatically displaying in the scanner was recorded respectively for the two groups while scanning.The effective dose（ED） was calculated according to the formula：ED=DLP×W（weighting factor,abdominal 0.015）.Actual mAs value of every image was recorded and the mean value was calculated in cases of the study group.Image quality at the top,portal and bottom of the liver on every image of 300 images was judged by two deputy chief physicians with double blind method,the image noise at the same position was measured and analyzed by statistics.Results：The effective mAs value of the study group maximumly decreased 54 than that of the contrast group with an average decrease of 18.46（12.31%）,the difference was statistically significant.In subjective judgment of the image quality,the ＂fine＂ images of the study group was 100.00% at the top of the liver,slightly higher than that of the contrast group（98.00%）;the ＂fine＂ of the two groups were both 100% at the portal,but the percentage of ＂excellent＂ films of controls（78%） was higher than that of the study group（46%）;the ＂fine＂ rate of the two groups were both 100% at the bottom of the liver.The measurement results of image noise in the two groups had no statistical significance（t=0.477,P0.05）.Conclusion：D-DOM technique provides a function that can regulate mAs real-time on line in the upper abdominal CT examination of children,it not only improves the utilization rate of radiation and decreases the radiation doses,but also ensures image quality,therefore having an obvious clinical application value.
出处
《放射学实践》
2012年第5期549-551,共3页
Radiologic Practice
