磁共振扩散加权成像对直肠癌T分期的诊断价值

Value of diffusion-weighted MRI in the diagnosis of T staging for rectal cancer

目的：探讨磁共振扩散加权成像（DWI）对直肠癌T分期的诊断价值。方法回顾性分析2013年7月至2014年9月间苏州大学附属常熟医院收治的46例直肠癌患者的临床病理和资料。比较磁共振单纯T2加权像（T2WI）与T2WI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。结果单纯T2WI与T2WI联合DWI两种成像方法诊断直肠癌T分期灵敏度、特异度和准确率的差异均无统计学意义（均P＞0．05）。病理T2、T3a、T3b、T3c和T4分期直肠癌DWI的ADC值分别为（1．110±0．117）×10-3 mm2／s、（1．035±0．121）×10-3 mm2／s、（0．948±0．109）×10-3 mm2／s、（0．932±0．122）×10-3 mm2／s 和（0．843±0．050）×10-3 mm2／s，差异有统计学意义（F＝6．972，P＝0．000）。结论 DWI可作为T2WI诊断直肠癌患者T分期的补充序列，肿瘤的ADC值随着直肠癌T分期的进展呈现下降趋势。

Objective To investigate the value of diffusion-weighted imaging （DWI） in the diagnosis of T staging for rectal cancer. Methods Clinicopathologic data and MR images of 46 patients with rectal cancer in our hospital from July 2013 to September 2014 were retrospectively analyzed. The diagnostic sensitivity, specificity and accuracy of T2WI were compared with those of T2WI plus DWI in T staging for rectal cancer. The relationship of mean apparent diffusion coefficient （ADC） value with different T stages of rectal cancer was analyzed. Results There were no significant differences in the diagnostic sensitivity, specificity and accuracy between T2WI and T2WI plus DWI （all P〉0.05）. The mean ADC value of DWI performed in pathologic T2, T3a, T3b, T3c and T4 stage was （1.110±0.117） ×10-3 mm2/s, （1.035±0.121）×10-3 mm2/s, （0.948±0.109）×10-3 mm2/s, （0.932±0.122）×10-3 mm2/s and （0.843±0.050）×10-3 mm2/s, respectively （F=6.972, P=0.000）. Conclusion DWI can serve as a complement for T2WI in the diagnosis of T stage patients with rectal cancer , and its ADC value presents a downward trend with the advance of T stage.