成人脑室相关病变低剂量CT复查的应用研究

目的：探讨成人脑室相关病变低剂量CT复查的可行性。方法：随机数字表法选取因脑室相关病变需行头部CT复查的成人患者68例,于常规剂量（Ⅰ组）CT扫描后,对含病变且无部分容积效应影响的层面行75%（Ⅱ组）和50%（Ⅲ组）常规剂量CT扫描。评价不同剂量组的图像质量及诊断效能。结果：图像质量比较经Wilcoxon符号秩检验Ⅰ组与Ⅱ组无统计学差异显著性（Z=-1.604,P=0.109）;Ⅰ组与Ⅲ组有统计学差异显著性（Z=-5.684,P=0.000）。诊断效能比较经McNemar检验Ⅰ组与Ⅲ组、Ⅱ组与Ⅲ组无统计学差异显著性（P=1）。结论：对于成人脑室相关病变CT复查病例,50%常规剂量CT扫描对临床诊断效能无显著影响。

The application study on low-dose CT for follow up of adult head with ventricular related lesions

Objective：To assess the feasibility of using low-dose CT for scanning adult head with ventricular related lesions in follow up cases.Methods：68 adult patients with ventricular related lesions who need follow up scans of CT were chosen with random number list method for a study of low-dose CT.After scans of the standard-dose（groupⅠ） CT,a slice containing lesion and without partial volume effect was chosen for the scans of 75% standard-dose（groupⅡ） and 50% standard-dose（group Ⅲ） CT.The image quality of all the three group of images was assessed with a 5-point scale.Randomized block designed Friedman M test was used for the comparison of the total difference of image quality rank among the three different dose levels.Wilcoxon signed-rank test was used for interblock comparison of the difference in image quality rank between images scanned with low-dose CT and standard-dose CT.If the difference in image quality rank between images scanned with different dose levels was statistically significant,McNemar test was applied to evaluate the difference in the CT diagnostic efficacy between different dose levels.Results：The total difference of image quality rank among the three different dose levels was statistically significant（X2=62.20,P=0.000）.The interblock comparison of the difference in image quality rank showed that the difference of image quality rank between groupⅠ and groupⅡwas not statistically significant（Z=-1.604,P=0.109）,the difference of image quality rank between group Ⅰ and group Ⅲ was statistically significant（Z=-5.684,P=0.000）,and the difference of image quality rank between group Ⅱ and group Ⅲ was also statistically significant（Z=-5.808,P=0.000）.However,the difference of CT diagnostic efficacy between group Ⅰ and group Ⅲ was not statistically significant（P=1）,and the difference of CT diagnostic efficacy between groupⅡ and group Ⅲ was also not statistically significant（P=1）.Conclusion：For follow up cases in adults with ventricle related lesions,low-dose CT with 50% dosage of standard-dose level can be used without obvious influence on diagnostic efficacy.