磁共振扩散加权成像对直肠癌T分期的诊断价值分析

Diagnostic value of magnetic resonance diffusion weighted imaging （DWI）in T staging of rectal cancer

目的：探讨磁共振扩散加权成像（diffusion-weighted imaging，DWI）在直肠癌 T 分期诊断中的临床应用价值。方法对2015年1-12月在武警浙江省总队嘉兴医院接受诊断与治疗的直肠癌患者采用磁共振单纯 T2加权像（T2 WI）和磁共振扩散加权成像（DWI）进行检查，对直肠癌进行术前 T 分期，比较单纯 T2 WI与 T2 WI 联合 DWI 两种成像方法诊断直肠癌 T 分期的灵敏度、特异度和准确率，分析直肠癌 DWI 的表观扩散系数（ADC 值）与 T 分期的关系。结果经统计 T2 WI 诊断准确率为65．22％（60／92），T2 WI 联合 DWI 诊断准确率为76．09％（70／92），两种诊断方法对直肠癌的 T 分期诊断准确率差异无统计学意义（χ2＝1．18，P ＞0.05）。T2和 T3 a 期 ADC 值明显高于 T3 b、T3 c 及 T4期，差异均有统计学意义（均 P ＜0．05）。结论DWI 可作为 T2 WI 诊断直肠癌 T 分期的补充序列，与病理分期一致性更好，肿瘤的 ADC 值随着直肠癌 T 分期的进展呈现下降趋势，为术前治疗方案的制定提供可靠的参考信息。

Objective To evaluate the clinical value of magnetic resonance diffusion weighted imaging （DWI）in T staging of rectal cancer.Methods Rectal cancer patients were accepted in our hospital from January 2015 to December 2015.Rectal cancer patients were examined with T2 weighted imaging （T2 WI）and magnetic resonance DWI and given preoperative T staging.The sensitivity,specificity and accuracy of T2 WI and T2 WI combined with DWI in the diagnosis of DWI staging of rectal cancer were compared,and the relationship between the apparent diffusion coefficient （ADC value）and T staging of rectal cancer was analyzed.Results The accurate rate of T2 WI in diagnosis was 65.22%（60 /92）,T2 WI and DWI diagnosis accurate rate was 76.09% （70 /92）.The two diagnostic methods of colorectal cancer T staging diagnosis accurate rate had no significant difference （χ2 =1.18,P 〉0.05）. Patients with good prognosis （T2 and T3 a）ADC value were significantly higher than the patients with poor prognosis in patients with ADC （T3 b,T3 c and T4 ）,and the differences were statistically significant （all P 〈0.05）.Conclusion DWI can be used as a complementary sequence for the diagnosis of T staging of rectal cancer by T2 WI.It had better consistency with pathologic stage.The ADC value of the tumor showed a decreasing trend along with the progression of T staging of rectal cancer,and provided reliable reference information for the preoperative treatment plan.