To combine intravoxel incoherent motion (IVIM) imaging and diffusion kurtosis imaging (DKI) parameters for the evaluation of radiotherapy response in rabbit VX2 malignant bone tumor model. Forty-seven rabbits with bone tumor were prospectively enrolled and divided into pre-treatment, considerable effect and slight effect group. Treatment response was evaluated using IVIM-DKI. IVIM-based parameters (tissue diffusion [Dt], pseudo-diffusion [Dp], perfusion fraction [fp]), and DKI-based parameters (mean diffusion coefficient [MD] and mean kurtosis [MK]) were calculated for each animal. Corresponding changes in MRI parameters before and after radiotherapy in each group were studied with one-way ANOVA. Correlations of diffusion parameters of IVIM and DKI model were computed using Pearson’s correlation test. A diagnostic model combining different diffusion parameters was established using binary logistic regression, and its ROC curve was used to evaluate its diagnostic performance for determining considerable and slight effect to malignant bone tumor. After radiotherapy, Dt and MD increased, whereas fp and MK decreased (p < 0.05). The differences in Dt, fp, MD, and MK between considerable effect and slight effect groups were statistically significant (p < 0.05). A combination of Dt, fp, and MK had the best diagnostic performance for differentiating considerable effect from slight effect (AUC = 0.913, p < 0.001). A combination of IVIM- and DKI-based parameters allowed the non-invasive assessment of cellular, vascular, and microstructural changes in malignant bone tumors after radiotherapy, and holds great potential for monitoring the efficacy of tumor radiotherapy.

中文翻译：

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体素内非相干运动成像结合扩散峰度成像评估兔 VX2 恶性骨肿瘤模型对放射治疗的反应

结合体素内不相干运动（IVIM）成像和弥散峰度成像（DKI）参数评估兔VX2恶性骨肿瘤模型的放射治疗反应。前瞻性入组47只骨肿瘤家兔，分为治疗前组、显效组和微效组。使用 IVIM-DKI 评估治疗反应。计算每只动物的基于 IVIM 的参数（组织扩散 [Dt]、伪扩散 [Dp]、灌注分数 [fp]）和基于 DKI 的参数（平均扩散系数 [MD] 和平均峰度 [MK]）。采用单因素方差分析研究各组放疗前后MRI参数的相应变化。IVIM和DKI模型的扩散参数的相关性使用Pearson相关检验计算。采用二元逻辑回归建立结合不同扩散参数的诊断模型，并利用其ROC曲线评估其诊断性能，以确定对恶性骨肿瘤的显着和轻微影响。放疗后，Dt 和 MD 增加，而 fp 和 MK 减少（p < 0.05）。显着影响组和轻度影响组之间 Dt、fp、MD 和 MK 的差异具有统计学意义（p < 0.05）。Dt、fp 和 MK 的组合在区分显着影响和轻微影响方面具有最佳诊断性能（AUC = 0.913，p < 0.001）。基于 IVIM 和 DKI 的参数的组合允许对放射治疗后恶性骨肿瘤的细胞、血管和微结构变化进行无创评估，