表观扩散系数值及相对表观扩散系数值对直肠腺癌分化程度的诊断价值

Value of Apparent Diffusion Coefficient and RelativeApparent Diffusion Coefficient in Grading Rectal Adenocarcinoma

目的探讨扩散加权成像(DWI)表观扩散系数(ADC)值和其与同层臀部肌肉的相对表观扩散系数(rADC)值对直肠腺癌的诊断价值。资料与方法 53例经肠镜确诊的直肠腺癌患者行常规MRI及DWI检查,测量瘤体ADC值并计算rADC值,比较不同分化程度直肠癌的ADC值及rADC值,分析ADC值及rADC值对低分化直肠腺癌的诊断效能。结果 53例直肠腺癌中,低分化13例,中分化30例,高分化10例;高、中、低分化直肠腺癌ADC值及rADC值分别为(1.180±0.110)×10-3mm2/s、0.964±0.097,(1.072±0.048)×10-3mm2/s、0.862±0.532,(0.882±0.109)×10-3mm2/s、0.677±0.109,差异有统计学意义(F=41.51、43.213,P<0.05)。以低分化程度为变量检验值绘制ADC值和rADC值ROC曲线,当ADC值为0.983×10-3mm2/s时,诊断低分化直肠腺癌的敏感度为92.3%,特异度为100.0%;rADC值为0.781时,诊断敏感度为92.3%,特异度为92.5%。结论 ADC值及rADC值与直肠腺癌的分化程度有关,有助于提高直肠腺癌的诊断准确性。

Purpose To determine the value of＂ apparent diffusion coefficient （ADC） and relative apparent diffusion coefficient （rADC） of diffusion weighted imaging （DWI） in the diagnosis of rectal adenocarcinoma. Materials and Methods Fifty-three patients with rectal adenocarcinoma confirmed by colonoscopy underwent routine MRI and DWI. The ADC value of tumors was measured and the rADC value was calculated. The results were compared among tumors with different differentiation degrees, and in particular, the values of ADC and rADC were analyzed among poorly differentiated rectal adenocarcinomas. Results Among all the 53 cases, 13 were poorly differentiated, 30 were moderately differentiated and 10 were well differentiated. The values of ADC value and rADC value with different degree were （ 1.180 ~ 0.110）x I 0~ mm2/s, 0.964 ~ 0.097; （ 1.072 ~ 0.048）x 103 mm2/s, 0.862 ~ 0.532; （0.882 ~ 0.109）~ 10.3 mm2/s, 0.677 ~ 0.109, respectively, with a significant difference （F-41.51 and 43.213, P〈0.05）. The ROC curve using poorly differentiated tumor as test variable of ADC and rADC values in tile diagnosis of illustrated that the sensitivity was 92.3% and specificity was 100.0% when tile cut-off of ADC value was 0.983x 10 ~ mm-~/s, while the sensitivity was 92.3% and specificity 92.5 % when the cut- offof rADC was 0.781. Conclusion The value of ADC and rADC is associated with tile differentiation degree of rectal adenocarcilaoma, thus is helpful to improve the accuracy of rectal adenocarcinoma diagnosis.