探讨3.0T MR扩散加权成像对直肠癌盆腔淋巴结转移的诊断价值。

回顾性分析经手术病理证实的53例直肠癌患者的临床资料、术前常规MRI及扩散加权成像(DWI)资料，以病理结果为参照，将淋巴结分为转移性和非转移性两组，分别测量定量参数ADC值，采用SPSS19.0软件包进行统计学处理，诊断效能采用ROC曲线分析，确定诊断转移性淋巴结的最佳临界点，计算诊断的敏感度、特异度和准确度。以P<0.05认为差异具有统计学意义。

116枚淋巴结中，转移性淋巴结47枚(40.5%)，非转移性淋巴结69枚(59.5%)。转移性淋巴结的ADC值为(0.81±0.10)×10^－3mm²/s明显低于非转移性淋巴结ADC值(1.06±0.13)×10^－3mm²/s，差异具有显著统计学意义(t＝10.47, P<0.01)；ROC曲线分析显示ADC值用于诊断转移性淋巴结的最佳临界点为0.95×10^－3mm²/s，其敏感度为91.5%，特异度为78.3%，准确度为83.6%。

3.0T MR扩散加权成像ADC值对直肠癌盆腔淋巴结转移具有较高的鉴别诊断价值，可为患者手术方案的选择和预后的评估提供更多的参考。

To investigate the diagnostic value of 3.0T MR diffusion weighted imaging (DWI) in pelvic lymph node metastasis of rectal cancer.

The clinical data and the conventional MRI and DWI data of 53 patients with postoperative pathological-proved rectal cancer were retrospectively analyzed. The lymph nodes were divided into metastatic and non-metastatic lesions according to pathological finding. ADC values of metastatic and non-metastatic lymph nodes were measured respectively. Statistical analysis was done by SPSS 19.0 program software. ROC curve was drawn, and the cutoff value for metastatic lymph nodes detection was determined, the sensitivity, specificity and accuracy were calculated. A P value <0.05 was considered as statistically significant.

In all 116 lymph nodes, there were 47 metastatic lymph nodes and 69 non-metastatic lymph nodes. ADC values of metastatic and non-metastatic lymph nodes were (0.81±0.10)×10^-3 mm²/s and (1.06±0.13)×10^-3 mm²/s respectively, the ADC values of metastatic lymph nodes were significantly lower than that of non-metastatic lymph nodes, the difference was statistically significant (t=10.47, P<0.05). ROC curve analysis showed that the ADC value for the best critical point of diagnosis for metastatic lymph nodes was 0.95×10^-3 mm²/s. The sensitivity was 91.5%, specificity was 78.3%, accuracy was 83.6%.

The value of 3.0T MR DWI ADC has high diagnostic value in pelvic lymph node metastasis of rectal cancer, which can provide more information for treatment and prognostic evaluation.