基于S-G滤波的超声造影分析参数灌注成像

Analysis of Parameter Perfusion Imaging for Contrast-Enhanced Ultrasound Based on S-G Filter

为弥补以往超声造影定量分析软件将感兴趣区(ROI)作为均质的整体区域进行分析的不足,提出一种基于S-G滤波器的在时域内直接处理数据平滑问题的定量分析方法,针对ROI区域内部像素点进行灌注成像参数分析,快速并可最大限度地保留原始有用信息。首先获得超声造影的原始DICOM动态医学数据,获取ROI内每个像素点的时间强度曲线,用S-G滤波器对时间强度曲线进行分析,得到反映灌注时相和灌注强度的多项定量分析参数,如到达时间(AT)、达峰时间(TTP)、达峰强度(PI)、平均通过时间(MTT)、曲线下面积(AUC)和上升斜率(RS)等;然后再对像素点参数分别进行彩色编码并以不同颜色显示,从而准确量化和直观显示超声造影的各项灌注参数。为评估该分析方法的稳定性,比较3位研究者分别对15个肝细胞癌病灶的分析结果。经统计,所有参数的组间相关系数(ICC)>0.80,验证了该方法的可行性和稳定性。

The previous perfusion analysis software for contrast-enhanced ultrasound（ CEUS） provided quantitative parameters under the assumption that the region of interest（ ROI） was a whole homogeneous perfusion area. To overcome the imperfection,we herein presented a fast data smoothing method with time domain based on S-G filter of ROI＇s internal regional perfusion imaging based on pixel parameter analysis. The time intensity curve（ TIC） of each pixel was obtained from the original DICOM dynamic imaging of CEUS data,the quantitative analysis of parameters of TIC were conducted based on the S-G filter,including time of arrival（ AT）,time to peak（ TTP）,peak intensity（ PI）,mean transit time（ MTT）,the area under the curve（ AUC）,and rising slope（ RS）. After that the pixel perfusion parameters coding was displayed in the color mode accurately and intuitively. The stability test was performed on 15 cases of hepatocellular carcinomas to obtain different quantitative parameters of TIC by three investigators respectively. The intraclass correlation coefficient of all parameters was more than 0. 80.