磁共振弥散加权成像结合常规序列在食管癌显示及术前分期中的应用

目的探讨磁共振弥散加权成像(DWI)结合常规序列对食管癌诊断及其在术前T分期中的临床应用价值。方法对30例被消化道内镜确诊为食管癌患者做常规MRI序列和DWI横断面扫描,b=500、800、1 000 s/mm2,然后分别计算其表观弥散系数值。在DWI结合常规序列图像上测量病变的长度,并与食管钡餐检查、CT、常规T2WI及手术切除病理大体标本的病变长度进行比较。结果所有食管癌病灶在MR-DWI上都是表现为高信号,且明显高于正常食管壁。随着b值增大,病灶的ADC值是逐渐减小的。MR-DWI结合常规序列显示的病变长度与病理结果显示的长度无统计学差异(P=0.955)且有着较高的相关性,与病理大体标本显示病变长度间的相关系数达到0.999,优于食管钡餐检查(r=0.858)、CT(r=0.971)和常规T2WI(r=0.985)。MR-DWI结合常规序列对于食管癌术前T3和T4期诊断准确率分别为85.71%和86.67%,优于常规MRI序列和CT检查,而对T1~2期诊断准确率仅为33.33%。结论 DWI结合常规序列在食管癌的诊断及T分期中具有一定的临床价值,可以为临床提供更多的影像学信息。

Magnetic resonance diffusion weighted imaging combined with conventional sequence in diagnosis of esophageal cancer and preoperative staging

Objective To evaluate the role of diffusion weighted imaging（ DWI） combined with conventional sequence in diagnosis of esophageal cancer and preoperative T staging. Methods Thirty patients diagnosed as esophageal cancer by gastrointestinal endoscopy underwent routine MRl and DWI crosssectional scanning（ b = 500,800,1 000 s /mm2）. And apparent diffusion coefficient（ ADC） was calculated.Lesion length was measured on the images of DWI combined with conventional sequences. Then the result was compared with esophageal barium meal,CT,routine T2 WI and surgical excision pathological specimen.Results Compared with normal esophageal vessel wall,strong signal presented in all esophageal cancer lesions in MR-DWI. The ADC of lesions was decreased when b value increased. The lesion length measured by MR-DWI combined with conventional sequence was not significantly different from pathological results（ P =0.955）. The correlation coefficient between MR-DWI and pathological results was 0.999,which was better than esophageal barium meal（ r = 0. 858）,CT（ r = 0. 971） and conventional T2WI（ r = 0. 985）. The diagnostic accuracy of MR-DWI combined with conventional sequence for preoperative T3 and T4 of esophageal cancer were 85. 71% and 86. 67%,respectively. It was superior to conventional MRI sequence and CT scanning. But the diagnostic accuracy of MR-DWI for T1-2 period was only 33. 33%. Conclusions DWI combined with conventional sequence is helpful in preoperative diagnosis of esophageal cancer and T staging.It can offer abundant imaging information for clinic.