CT重建层厚和定位光精度自动分析方法研究  

Automatic analysis method of CT reconstruction layer thickness and localization optical accuracy

作　　者：徐小三[1] 杜翔[1] 杨春勇[1] 王进[1] XU Xiao-san;DU Xiang;YANG Chun-yong;WANG Jin(Jiangsu Provincial Center for Disease Control and Prevention(Jiangsu Provincial Academy of Preventive Medicine),Nanjing 210009,China)

机构地区：[1]江苏省疾病预防控制中心(江苏省预防医学科学院),南京210009

出　　处：《医疗卫生装备》2024年第12期50-54,共5页Chinese Medical Equipment Journal

基　　金：江苏省医学重点学科(ZDXK202249)。

摘　　要：目的:提出一种用于测量CT重建层厚和定位光精度的自动分析方法。方法:以CT扫描Catphan500型检测模体的CTP401模块重建后的图像为研究对象,采用斜线法和交叉斜线法,借助MATLAB软件,利用OTSU算法实现对CT重建层厚和定位光精度的自动分析,得出CT重建层厚和定位光精度的测量结果,并对2种方法测量结果的准确性进行对比分析。结果:采用斜线法根据3点、6点、9点和12点处金属丝的长度计算所得的CT重建层厚分别为10.69、10.69、10.49和10.69 mm,根据3点、6点、9点和12点处金属丝影像中心到模块中心的距离计算所得的定位光精度分别为-0.092、0.079、0.060和-0.014 mm;采用交叉斜线法根据3点和9点处金属丝的长度计算所得的CT重建层厚为10.70 mm,根据6点和12点处金属丝的长度计算所得的CT重建层厚为10.80 mm,根据3点、6点、9点和12点处金属丝影像中心到模块中心的距离计算所得的定位光精度分别为-0.092、0.080、0.061和-0.014 mm。采用交叉斜线法计算得到的CT重建层厚更接近真实值,采用斜线法和交叉斜线法测得的定位光精度在相应点位处的数值基本相同。结论:提出的自动分析方法可客观、准确地测量CT重建层厚和定位光精度。Objective To propose an automatic analysis method for CT reconstruction layer thickness and localization optical accuracy.Methods The reconstructed images by scanning the CTP401 module of Catphan500 detection phantom with an X-ray computed tomography device were selected as the research objects.The oblique line method and cross diagonal method were used for the automatic analyses of CT reconstruction layer thickness and localization optical accuracy by using MATLAB software and OTSU algorithm,so as to obtain the detection results for CT reconstruction layer thickness and localization optical accuracy.The two methods were compared in terms of the accuracy of the detection results.Results By the oblique line method,the CT reconstruction layer thicknesses calculated with the lengths of the wires at 3,6,9 and 12 o'clock positions were 10.69,10.69,10.49 and 10.69 mm respectively,and the localization optical accracies calcultaed with the the distance from the center of the wire image to the center of the module at 3,6,9 and 12 o'clock positions were-0.092,0.079,0.060 and-0.014 mm respectively;by the cross diagonal method,the CT reconstruction layer thicknesses calculated with the lengths of the wires at 3 and 9 o'clock positions and at 6 and 12 o'clock positions were 10.70 mm and 10.80 mm respectively,and the localization optical accracies calcultaed with the the distance from the center of the wire image to the center of the module at 3,6,9 and 12 o'clock positions were-0.092,0.080,0.061 and-0.014 mm respectively.The CT reconstruction layer thicknesses by the oblique line method were closer to the true values than those by the cross diagonal method,and the localization optical accuracies by the two methods were basically the same at the corresponding positions.Conclusion The automatic analysis methods proposed can detect CT reconstruction layer thickness and localization optical accuracy objectively and accurately.

关 键 词：CT重建层厚 定位光精度 斜线法 交叉斜线法 

分 类 号：R318.6[医药卫生—生物医学工程] TH774[医药卫生—基础医学]