目的 探讨不同b值ADC图对宫颈 癌放化疗早期疗效价值。方法 40例IIbIVa期宫颈癌患者，于治疗前、外照射2-3 周、3次后装及放化疗后,行常规MRI及DWI 扫描。按随访结果将患者分为完全缓解组 (24例)、部分有效组(16例)，测肿瘤最大 径、ADC值，根据ROC曲线评价不同b值ADC 图价值。结果 在外照射2-3周及3次后装 后，两组肿瘤缩小比差异无统计学意义 (P>0.05)。外照射2-3周后，b=0、200， 0、400，0、600,0、800,0，1000s/mm2 的ROC下面积为0.844、0.833、0.948、 0.950、0.958；灵敏度为66.7％、75％、 83.3％、84.5％、91.7％，特异度均 为100％；3次后装后，b=0、200，0、 400，0、600,0、800,0，1000s/mm2的ROC 下面积为0.885、0.802、0.948、0.949、 0.974；灵敏度为75％、75％、85％、 83.3％、91.8％，特异度均为100％；结 论 评价宫颈癌早期放化疗疗效时，高b值 (b=0、600，0、800，1000s/mm2)较低b值 (b=0、200，0、400s/mm2)价值高。

Objective To observe the evaluation of early chemoradiothempy efficacy in uterine cervical cancer by the different b-value ADC images. Methods 40 patients with middle and advanced stage uterine cervical cancer in stage IIb-IVa were recruited and received 4 conventional MRI and DWI exams before treatment, after 2-3 weeks , 3 times after intracavitary irradiation treatment and after treatment.The patients were divided into complete remission(CR)group(24 cases), partial remission(PR)group(16 cases)according to the changes in tumor size after 8 months of treatment. The tumor size and apparent diffusion coefficient(ADC)of uterine cervical cancer were measured at each examination among the 2 groups. According the receiver operating characteristic(ROC)curve, chemoradiotherapy efficacy and prognosis value of different b-value of ADC images in uterine cervical cancer were compared. Results There were no significant differences of the tumor shrinking rate after 2-3 weeks and 3 times after intracavitary irradiation treatment in the 2 groups(P>0.05). After 2-3 weeks treatment, at b=0,200, 0,400, 0,600, 0,800, 0,1000 s/mm2 ADC images, ROC area under curve was 0.844、0.833、0.948、 0.950, 0.958, sensitivity Was 66.7％, 75％, 83.3％, 84.5％, 91.7％, specificity was 100％, in 3 times after intracavitary irradiation treatment, at b=0,200, 0,400, 0,600, 0,800, 0,1000 s/mm2 ADC images, ROC area under curve was 0.885, 0.802, 0.948, 0.949, 0.974, sensitivity Was75％, 75％, 85％, 83.3％, 91.8％, specificity was 100％. Conclusion When evaluating the early chemoradiothempy effect of cervical cancer, High value(b=0, 600, 0, 800, 1000 s/mm2 ) are better than lower b value(b=0, 200, 0, 400 s/mm2 ).