直肠MR扩散加权成像对淋巴结性质的判定与病理学的对照研究

目的：探讨磁共振扩散加权成像对直肠肿瘤肠周淋巴结性质的鉴别诊断价值。方法：采用PHILIPS3．0T超导型磁共振成像仪及体部相控阵线圈对43例直肠癌、2例淋巴瘤行常规MRI及DWI扫描．选取≥5mm同时在DwI图像上表现为高信号的淋巴结测量ADC值．与病理学对照其性质并进行统计学分析：依据美国癌症联合委员会直肠癌TNM分期标准，采用双盲法对直肠癌常规MRI及常规MRI＋DWI2种检查方法术前N分期的准确性进行比较。结果：直肠癌病例转移性淋巴结与非转移性淋巴结的ADC值差异无统计学意义（P〉0．05）．直肠淋巴瘤病例淋巴结的ADC值低于直肠癌转移性淋巴结及非转移性淋巴结，差异有统计学意义（P〈0．05）；常规MRI及常规MRI＋DWI对术前N分期的结果差异无统计学意义（P〉0．05）。结论：扩散加权成像可以快速发现可疑、异常淋巴结，在淋巴结性质的判定方面具有一定的诊断价值。

Comparative Study of MR Diffusion Weighted Imaging and Pathological Examination for Rectum Lymph Node

Objective To evaluate the role of diffusion-weighted imaging in the differential diagnosis of rectal tumor lymph nodes properties. Mothods Conventional MR imaging and DWI were performed in 43 cases of rectal cancers and 2 cases of lymphoma by using PHILIPS 3.0T scanner and body phased-aiTay coil. The lymph nodes with the diameter not less than 5ram and high signals in DWI image had their ADC values measured, and the results were compared with those by pathological examination and analyzed statistically. The preoperative staging（N） accuracies by conventional MRI or conventional MRI combined with DWI were compared by double-blinded pattern according to the TNM staging system of AJCC. Results For rectum cancer patient, there was no statistical difference between the ADC values of the metastatic lymph nodes and those of non-metastatic ones, with P〈0.05. The ADC values of the lymph nodes of the rectum lymphoma patient were significantly less than those of the rectum cancer patient, with P〈0.05. There was no statistical difference between the preoperative staging（N） results by conventional MRI and combined MRI and DWI, with P〉0.05. Conclusion Diffusion-weighted imaging can quickly find abnormal lymph nodes, and has a certain diagnostic value in the determination of lymph node properties