CT/MR图像融合在食管癌精确放疗大体肿瘤靶区勾画中的应用价值

目的 探讨CT与MR图像融合在食管癌大体肿瘤靶区（GTV）勾画中的应用价值。方法 收集行根治性食管癌切除术的29例食管鳞癌患者，术前行常规CT扫描及磁共振T2WI、磁共振扩散加权成像（DWI），扩散敏感梯度b值取400、600、800 s/mm²，分别在CT图像、CT/MR T2WI融合图像以及CT/MR DWI融合图像上勾画食管癌GTV，测量GTV长度，并与术后病理标本的病变长度比较，探讨CT/MR融合图像上勾画的食管癌GTV长度的准确性。结果 CT图像上测量的食管癌GTV长度为 （44.94±18.46）mm，CT/MR T2WI融合图像上测量食管癌GTV长度为（45.05±21.47）mm。b值为400、600、800 s/mm²时，CT/MR DWI融合图像上测量的GTV长度分别为（42.12±17.79）、（41.18±17.17）、（39.77±17.66）mm；与术后病理标本的病变长度的相关系数分别为0.928、0.926和0.927。结论 CT与MR DWI图像进行图像融合，能够为食管癌GTV长度的确定提供帮助，从而对GTV的勾画起到一定的指导作用。

Application of CT/MR image fusing in gross tumor volume delineation of esophageal squamous cell carcinoma

Objective To investigate the application value of CT/MR image fusing in gross tumor volume (GTV) delineation of esophageal squamous cell carcinoma. Methods Twenty-nine patients with esophageal squamous cell carcinoma to be treated with radical surgery underwent routine CT scanning, MR T2-weighted imaging (T2WI) and diffusion weighted imaging(DWI)before surgery. Diffusion-sensitive gradient b values were taken at 400, 600, and 800 s/mm². GTVs were delineated on the CT image, CT/MR T2WI, and CT/MR DWI respectively. The MR T2W1 image was used as the intermediary for the fusion of the CT image and MR DWI image. The length of GTVs measured under different imaging conditions were compared with the length of the resected specimen of esophagus. Results The GTV length was (44.94±18.46) and (45.05±21.47) mm on the CT images and CT/MR T2WI images respectively. When the b values were 400, 600, and 800 s/mm², the esophageal carcinoma GTV length on CT/MR DWI images was (42.12±17.79), (41.18±17.17) and (39.77±17.66) mm, respectively. The coefficient between the esophageal carcinoma GTV lengths on CT/MR DWI images and the pathological lesion lengths was 0.928, 0.926 and 0.927 respectively. Conclusions CT/MR DWI images displays esophageal carcinoma GTV length more accurately, thus guiding the delineation of GTV effectively.