功能CT中图像预处理对评估肿瘤的影响

Influence of image preprocessing on the assessment of tumors with functional CT

目的探索一种合适的AM中值滤波窗口,以使通过示踪剂动力学模型得到的功能参数和功能图片可以准确表征肿瘤的生长状态。方法对原始CT序列图像进行不同窗口下的AM中值滤波,通过示踪剂动力学模型获取相应的功能参数及其功能图片;对功能图片中的肿瘤进行分割和测量,比较不同滤波窗口下肿瘤形态的差异性。结果滤波窗口越大,所获得的功能参数值越准确;同时肿瘤区域逐渐增大,肿瘤的面积变大,由于边缘的毛刺、突起等得到平滑,周长反而减小;不同滤波窗口下肿瘤区域的灌注参数与正常组织的灌注参数值差异均有统计学意义,且滤波窗口越大,差异性越明显。结论在3×3AM中值滤波预处理基础上得到的功能参数和功能图片可以准确地表征肿瘤的生成状态。

Objective To explore appropriate filter template in order to obtain the perfusion values and functional maps that can accurately represent the angiogenesis of tumors. Methods First,the method of AM median filter in different template was used to preprocess the original CT sequence images,and the perfusion values and functional maps were obtained through physiological models. Then the difference of tumor shapes in different filter template,and the difference of perfusion value between normal tissue and tumor regions were compared. Results The functional parameters became more accurate and tumor region and tumor area gradually increased with the increase of the filter window. However,as a result of the smooth of the protuberance and burr,tumor perimeter decreased. There were statistical differences between normal tissue and tumor region at different filter windows,and the differences became more obvious with the increase of the filter window. Conclusion The perfusion values and functional maps obtained after image processing at the case of the template of 3×3 can accurately represent the angiogenesis of tumors.