DWI在食管癌定量及定期诊断中的价值

The Value of DWI in the Quantitative and Staging Evaluation of Esophageal Cancer

目的探讨磁共振扩散加权成像(DWI)在食管癌诊断及其术前T分期中的临床价值。方法 45例经消化道内镜诊断为食管癌患者行常规MRI及DWI横断面扫描,b=500、800、1000 s/mm2,分别计算表观扩散系数(ADC)值及信噪比(SNR);在不同b值下DWI图像上测量病变长度,并与食管钡餐造影、CT、常规T2WI及手术切除病理大体标本的病变长度进行比较且行相关性分析;分别应用不同影像学方法对食管癌行术前T分期,并与病理分期间行Kappa一致性检验。结果 45例食管癌病灶在MR-DWI上均呈高信号,高于正常食管壁。随着b值增大,病变ADC值逐渐减小,分别为(1.77±0.27)×10-3mm2/s、(1.61±0.29)×10-3mm2/s、(1.39±0.24)×10-3mm2/s,其SNR逐渐减低。b值为500、800、1000 s/mm2时,DWI及T2WI、食管钡餐造影显示病变长度与病理结果间均无显著性差异(P﹥0.05);CT显示病变长度与病理结果间有显著性差异(P=0.039);不同影像学方法测量病变长度与病理标本间相关性系数以b值=500 s/mm2DWI最高(r=0.992)。DWI结合常规序列对于食管癌术前T分期诊断与病理分期间的吻合系数(k值)为0.733(较强),高于常规MRI序列(k值=0.578)和CT检查(k值=0.323)。结论 DWI结合常规序列在食管癌的定量诊断及分期诊断中具有一定的临床价值,可以为临床提供更为丰富的影像学信息。

Objective To evaluate the clinical value of diffusion weighted imaging （DWI） in preoperative diagnosis and T staging of esophageal cancer. Methods 45 patients with gastrointestinal endoscopy esophageal cancer underwent routine MR1 and DWI cross sectional scanning, b = 500,800,1000 s/mm^2 , ADC values and SNR were respectively calculated. In different b value of DWI, the length of lesion was measured and compared with esophageal barium meal, CT, routine T2WI and surgical excision pathological gross specimen lesions length and correlation analysis was taken. Different imaging methods were applied in esophageal preoperative T stage, and Kappa was performed with pathological examination. Results All esophageal cancer lesions had high signal on MR DWI, which was obviously higher than that of the normal feeding tube wallo Along with the b value increased, the lesions ADC values decreased,respectively （ 1.77 ＋ 0.27）× 10^-3 mm^2/s,（ 1.61 ± 0.29） × 10^-3 mm^2/s, （1.39 ＋ 0.24） × 10^-3mm^2/s, and their SNR decreased. When the b value was 500, 800, 1000 s/mm2, there were no significant difference between DWI, T_2WI, esophageal barium meal radiography and pathological results in lesions length （P 〉 0.05 ） ; there were significant difference between CT and pathological results in lesions length（P =0. 039）. The correlation coefficient between different imaging methods measuring lesions length with pathological when b value = 500 s/mm^2 was highest （ r = 0.992）. The match coefficient between DWI combined with convention sequence for esophageal cancer preoperative T stage diagnosis and pathological points was 0. 733 （strong）higher than conventional MRI sequence （k value = 0. 578 ） and CT examination （ k value = 0. 323 ）. Conclusion DWI combined with conventional sequence in quantitative and staging evaluation of esophageal cancer have certain clinical value, it can offer more abundant imaging information for clinical.