管电压对增强CT影像组学特征影响的体模研究

The Effect of Tube Voltage on Features of Contrast Enhanced CT Images

目的探讨管电压对增强CT影像组学特征的影响。方法把碘帕醇注射液稀释后溶液(含碘浓度范围为370~0 mg/ml)分别编为1~17号,模拟不同的强化程度。在自制体模中装满蒸馏水,然后将5 ml溶液和5 ml蒸馏水试管固定其中。应用Siemens 64排Siemens Definition AS+CT机对体模进行头部序列扫描,使用Caredose4D,层厚5 mm,软组织重组算法,管电压分别为70 kV、80 kV、100 kV、120 kV、140 kV,视野(FOV)为300 mm×300 mm。在基于ITK4.3.2/VTK5.10.1/Qt2013.12.00的GE AK影像组学平台上进行目标勾画。然后提取灰度直方图特征42个、灰度区域矩阵特征(GLSZM)11个、Haralick特征(Haralick)10个、灰度运程矩阵特征(GLRLM)180个,采用变异系数(CV)评价特征的稳定性。结果4~17号溶液十分稳定的特征个数分别为151、147、135、143、97、49、45、42、33、34、33、33、33、32个。在一定强化范围内,稳定的特征个数随着强化程度的升高而增加,但部分浓度溶液某些特征的稳定性基本不受管电压影响。结论管电压对增强CT图像的影像组学特征影响很大,强化程度的变化会导致部分特征对管电压的敏感性改变,高强化程度的增强CT图像能提供更多的稳定特征。

Objective To explore the influence of tube voltage on the imaging characteristics of enhanced CT imaging.Methods The iodine concentration range of the diluted iopamidol injection solution was 370~0 mg/ml,numbered 1~17 respectively,to simulate different degrees of enhancement.We filled the self-made phantom with distilled water,and then fixed the 5 ml solution and 5 ml distilled water test tube in it.We used Siemens 64-row Siemens definition AS+CT to scan the head sequence of the phantom,using Caredose4 D,layer thickness 5 mm,soft tissue reconstruction algorithm,tube voltages were 70 kV,80 kV,100 kV,120 kV,140 kV,FOV is 300×300 mm.The target is delineated on the GE AK imaging platform based on ITK4.3.2/VTK5.10.1/Qt2013.12.00.We then extracted 42 gray histogram features(Histogram),gray level size zone matrix features(Gray Level Size Zone Matrix,GLSZM)11,Haralick features(Haralick)10,gray level run length matrix features(Gray Level Run Length Matrix.There were 180 GLRLMs,and the coefficient of variation(CV)was used to evaluate the stability of features.Results The number of stable features were 151、147、135、143、97、49、45、42、33、34、33、33、33、32,respectively,in corresponding to different solutions from number 4 to 17.In a certain range,the number of stable features increases with the increase of the concentration of solution,butthe stability of partial features is insensitive to tube Voltage.Conclusion The study shows that tube voltage has a great influence on contrast-enhanced CT imaging features,and the change of enhancement degree will lead to the change of sensitivity of some features to tube voltage,and enhanced CT images with high enhancement degree can provide more stable features.