融合图像放疗靶区定位精度的检验和初步临床结果

目的：探讨以图像融合技术为基础的肿瘤三维适形放疗靶区定位精度的检验及依据融合图像放疗靶区的确定与单纯CT影像放疗靶区确定的初步临床结果。方法：利用定制的模体分别行CT、MRI和PET成像，进行CT与MRI，CT与PET融合。检验融合后定制标记点的定位精度。对3例特殊病例分别以单纯CT图像为基础和融合图像为基础，进行三维适形放疗靶区认定，对不同医生之间和同一医生在不同时间，放疗靶区定义情况进行对照分析。结果：MRI／CT融合图像总定位精度小于2mm，PET／CT图像融合图像融合精度情况（包括同机融合和异机融合），采用不同的融合算法。定位精度有显著差异（P〈0．01，t=5．385）。单纯利用CT图像进行靶区的定义，不同医生之间，在不同的时间存在差异（P〈0．05），而采用融合技术可减少他们的争议和差异。结论：利用多模式图像融合可以提高靶区定义的准确性．有利于三维适形精确放射治疗。

Analysis Precise of Fused Medical Images and Preliminary Clinical Results

Objective： To analyze the precise of fused medical images and discuss the preliminary clinical results based on fused images. Methods： Based on brain and body phantom CT,MRI and PET images, we got CT and MRI fusion images, PET and CT fusion images. These special points were calculated in the fusion images and compared with the same points in the X ray films to find location error. As simply using CT images to find tumor site, it is normally some deviation and not definition position. We let different doctors definition three different tumors in the three patients to fred the deviation and error position, and the images which have different mode images （CT, MRI, and PET image ） fusion based on internal information algorithm and external markers algorithm. Results： To analyze these different results in different fusion images, we found that the precise of location in CT and MRI fusion images was less than 2 mm （range, 1 mm-2 mm）.Using different image registration methods, we found the accuracy of PET/CT was 2 mm-3 mm, 2 mm-5 mm respectively and there was statistical difference between two registration methods （P 〈0.01 t =5.385） in the same PET/CT scanner. In the CT images definition tumor areas, different doctors and different time have different results, which have some disputes and these differences have statistical effects （P〈0.05）. But for the image fusion defmition, these disputes have statistically decreased in the different doctors＇ definitions and on the different time. Conclusions： To utilize multiple mode images fusion can increase precise definition targets＇ positions and take advantage of three dimension precise radiotherapy.