DWI对直肠黏液腺癌与非黏液腺癌的鉴别诊断价值

目的:探讨磁共振扩散加权成像(DWI)及其表现扩散系数(ADC)值对直肠黏液腺癌与非黏液腺癌的鉴别诊断价值.方法:回顾性分析经手术病理证实的16例直肠黏液腺癌与64例非黏液腺癌患者的MR资料,观察所有肿瘤的DWI信号强度,测量肿瘤ADC值及相对ADC(rADC)值,并绘制受试者工作特性(ROC)曲线,计算ADC值及rADC值对直肠黏液腺癌与非黏液腺癌的鉴别诊断效能.结果:16例直肠黏液腺癌中4例在DWI图像上呈低号,12例呈高信号,64例非黏液腺癌中1例呈低信号,63例呈高信号,两者DWI信号强度差异有统计学意义(x2=8.333,P=0.004).黏液腺癌的ADC值[(1.48±0.25)×10 3 mm2/s]及rADC值(1.22±0.18)均高于非黏液腺癌[(1.08±0.11)×101 mm2/s,(0.95±0.11)],差异均具有统计学意义(t=6.162,P＜0.001;t=5.810,P＜0.001).以ADC值=1.209×10 3mm2/s鉴别诊断黏液腺癌与非黏液腺癌的效能最高(AUC 0.923,敏感度93.8％,特异度89.1％).结论:DWI及ADC值在直肠黏液腺癌与非黏液腺癌的鉴别诊断中具有重要价值.

The value of DWI and ADC in differentiating mucinous and nonmucinous rectal adenocarcinoma

Objective:To investigate the role of DWI and ADC value in differentiating mucinous and nonmucinous rectal adenocarcinoma.Methods:Sixteen patients with mucinous rectal adenocarcinoma and sixty-four patients with nonmucinous adenocarcinoma proved by surgery and pathology were enrolled and analyzed retrospectively.The signal intensity of DWI in all tumors were asscessed.ADC and rADC values were calculated in the region of interest (ROD of tumor.The significance of ADC and rADC values in differentiating mucinous and nonmucinous adenocarcinoma were calculated.Results:Of the 16 patients with mucinous adenocarcinoma,there were 4 patients showing low signal intensity on DWI and 12 patients showing high signal intensity;of the 64 patients with non-mucinous adenocarcinoma,1 patient showed low signal intensity and 63 patients showed high signal intensity,with significant statistic difference (x2 =8.333,P=0.004).The ADC and rADC values of mucinous adenocarcinoma [(1.48 ± 0.25) × 10 3 mm2/s;(1.22 ± 0.18) respectively] were significantly higher than those of nonmucinous adenocarcinoma [(1.08±0.11) × 10 3mm2/s,(0.95±0.11) respectively],with significant statistic differences (t=6.162,P＜0.001;t=5.810,P＜0.001 respectively).Setting the ADC value 1.209× 10-3mm2/s as the threshold for differentiating mucinous adenocarcinoma and nonmucinous adenocarcinoma,the optimal diagnostic value could be achieved (AUC,0.923;sensitivity,93.8 ％;specificity,89.1％).Conclusion:DWI and ADC value played an important role in differentiating mucinous and nonmucinous rectal adenocarcinoma.