目的 分析扩散峰度成像(DKI)在 局部晚期直肠癌患者新辅助放化疗早期疗 效的预测价值。方法 回顾性分析2014年 9月-2017年6月在我院接受新辅助放化疗 的36例局部晚期直肠癌患者的MRI影像资 料，行DKI后处理获取治疗前、治疗2周及 3周时的ADC、D、K等定量值，分析DKI在 局部晚期直肠癌患者新辅助放化疗早期疗 效预测价值。结果 36例局部晚期直肠癌 中新辅助放化疗有效率41.67%(15/36)； 且治疗2周时、3周时有效组ADC值高于无 效组(P﹤0.05)；新辅助放化疗前、治疗 2周时有效组D值均显著低于无效组(P﹤ 0.05)，2周及3周时△D值高于无效组(P﹤ 0.05)；但两组任意时间点的定量值K、 △K组间差异无统计学意义(P﹥0.05)；而 ADC、△ADC、D、△D、△K均与TRG评分有 显著相关性(P﹤0.05)，K值相关性不显著 (P﹥0.05)；且△ADC、△D预测新辅助放化 疗早期疗效时效能最佳，ROC曲线下面积 分别为0.769、0.845，诊断的敏感性及 特异性分别为57.25%、100%及100.00%、 62.49%。结论 DKI或可成为预测局部晚期 直肠癌患者新辅助放化疗早期疗效的有效 手段，于此类患者治疗方案的确定有重要 指导价值。

Objective To analyze the value of diffusion kurtosis imaging (DKI) in predicting early curative effect of neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer. Methods The MRI data of 36 patients with locally advanced rectal cancer who underwent neoadjuvant chemoradiotherapy in the hospital from September 2014 to June 2017 were analyzed retrospectively. DKI was performed to obtain ADC, D, K and other quantitative values before the treatment and after 2 weeks and 3 weeks of treatment. The value of DKI in predicting early curative effect of neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer was analyzed. Results The effective rate of neoadjuvant chemoradiotherapy in the 36 cases was 41.67% (15/36), and the ADC values of the effective group were higher than those of the ineffective group after 2 weeks and 3 weeks of treatment (P<0.05).D values of the effective group were significantly lower than those of the ineffective group before neoadjuvant chemotherapy and after 2 weeks of treatment (P<0.05). Besides, △D values were higher than those of the ineffective group after 2 weeks and 3 weeks of treatment (P<0.05). However, there was no statistically significant difference in K values or △K values between the two groups at any time point (P>0.05). There was an obvious correlation between ADC, △ADC, D, △D, △K and TRG score(P<0.05), but the correlation of K value was not significant (P>0.05). The efficiencies of △ADC and △D were the best in predicting early curative effect of neoadjuvant chemoradiotherapy. The areas under the ROC curve were 0.769 and 0.845, and the sensitivities and specificities were 57.25%, 100% and 100%, 62.49%, respectively. Conclusion DKI is an effective way to predict the early curative effect of neoadjuvant chemoradiotherapy for locally advanced rectal cancer, which is of guiding value in the treatment of such patients.