目的 探讨磁共振成像(MRI)在直 肠癌术前TN分期中的诊断价值。方法 选 取2016年2月至2017年3月在我院治疗的直 肠癌患者68例，术前行MRI扫描，扫描序 列包括T2WI和磁共振弥散加权成像(DWI) (b=0,1000s/mm2 )，分析T2WI术前TN分期 与术后病理结果，DWI测量不同T分期病 灶表观弥散系数(ADC)值。结果 术后病 理T分期：≤T2期10例、T3期39例、T4期 19例；术后病理N分期：N0期45例、N1期 17例、N2期6例；MRI术前T分期与病理结 果一致性Kappa值=0.642，P＜0.05，MRI 术前T分期准确率为79.41%；MRI术前N分 期与病理结果一致性Kappa值=0.244，P ＜0.05，MRI术前N分期准确率为57.35%； T1+2期病灶ADC值为(1.104±0.122)×10- 3 mm2 /s，明显高于T3期和T4期(P＜0.05)。 结论 MRI在直肠癌术前T分期诊断中有较 好的应用价值，在N分期诊断中准确率较 低；ADC值在术前T分期诊断中有一定价 值。

Objective To investigate the diagnostic value of magnetic resonance imaging (MRI) in the preoperative TN staging of rectal cancer. Methods 68 cases of rectal cancer treated in our hospital from February 2016 to March 2017 were selected, MRI scan was performed before the operation, and the scanning sequence included T2WI and magnetic resonance diffusion weighted imaging (DWI) (b=0,1000s/mm2 ). The preoperation TN staging of T2WI and postoperative pathological results were analyzed, the apparent diffusion coefficient (ADC) of different T staging lesions (ADC) was measured by DWI. Results The postoperative pathological T staging: 10 cases of ≤T2, 39 cases of T3, 19 cases of T4, postoperative pathological N staging: 45 cases of N0, 17 cases of N1, 6 cases of N2. The Kappa value of T staging of MRI before operation and pathological results was=0.642, P<0.05, and the accuracy rate of T staging of MRI before operation was 79.41%. The Kappa value of N staging of MRI before operation and pathological results was=0.244, P<0.05, and the accuracy rate of N staging of MRI before operation was 57.35%. The ADC value of the T1+2 phase was (1.104±0.122)×10-3mm2 /s, which was significantly higher than that of T3 and T4 (P<0.05). Conclusion MRI has a good application value in the diagnosis of preoperative T staging of rectal cancer, and its N stage diagnosis accuracy is low. ADC value plays a certain role in preoperative T stage diagnosis.