Objective

ADC (Apparent Diffusion Coefficient) derived from Diffusion-Weighted Imaging (DWI) has shown promise as a non-invasive quantitative imaging biomarker in Wilms’ tumours. However, many non-Gaussian models could be applied to DWI. This study aimed to compare the suitability of four diffusion models (mono exponential, IVIM [Intravoxel Incoherent Motion], stretched exponential, and kurtosis) in Wilms’ tumours and the unaffected contralateral kidneys.

Materials and methods

DWI data were retrospectively reviewed (110 Wilms’ tumours and 75 normal kidney datasets). The goodness of fit for each model was measured voxel-wise using Akaike Information Criteria (AIC). Mean AIC was calculated for each tumour volume (or contralateral normal kidney tissue). One-way ANOVAs with Greenhouse–Geisser correction and post hoc tests using the Bonferroni correction evaluated significant differences between AIC values; the lowest AIC indicating the optimum model.

Results

IVIM and stretched exponential provided the best fits to the Wilms’ tumour DWI data. IVIM provided the best fit for the normal kidney data. Mono exponential was the least appropriate fitting method for both Wilms’ tumour and normal kidney data.

Discussion

The diffusion weighted signal in Wilms’ tumours and normal kidney tissue does not exhibit a mono-exponential decay and is better described by non-Gaussian models of diffusion.

中文翻译：

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Wilms 肿瘤和正常对侧肾组织中扩散模型的比较。

客观的

源自扩散加权成像 (DWI) 的 ADC（表观扩散系数）已显示出作为 Wilms 肿瘤中非侵入性定量成像生物标志物的前景。然而，许多非高斯模型可以应用于 DWI。本研究旨在比较四种扩散模型（单指数、IVIM [Intravoxel Incoherent Motion]、拉伸指数和峰态）在 Wilms 肿瘤和未受影响的对侧肾脏中的适用性。

材料和方法

回顾性审查了 DWI 数据（ 110 个维尔姆斯肿瘤和 75 个正常肾脏数据集）。每个模型的拟合优度是使用 Akaike 信息标准 (AIC) 按体素测量的。计算每个肿瘤体积（或对侧正常肾组织）的平均 AIC。使用 Greenhouse-Geisser 校正的单向方差分析和使用 Bonferroni 校正的事后检验评估了 AIC 值之间的显着差异；表示最佳模型的最低 AIC。

结果

IVIM 和拉伸指数提供了与 Wilms 肿瘤 DWI 数据的最佳拟合。IVIM 为正常肾脏数据提供了最佳拟合。单指数是最不适合 Wilms 肿瘤和正常肾脏数据的拟合方法。

讨论

Wilms 肿瘤和正常肾组织中的扩散加权信号没有表现出单指数衰减，并且可以通过非高斯扩散模型更好地描述。