Department of Radiology, Zibo Central Hospital, Zibo, Shandong, China; Zibo Key Laboratory of Precision Neuroimaging, China.
Department of Nephrology, Zibo Central Hospital, Shandong, China.
Eur J Radiol. 2020 Sep;130:109195. doi: 10.1016/j.ejrad.2020.109195. Epub 2020 Jul 26.
To evaluate the role of diffusion kurtosis imaging (DKI) in the characterization of clear cell renal cell carcinoma (ccRCC) compared with standard diffusion-weighted imaging (DWI).
89 patients with histologically proven ccRCC were evaluated by DKI and DWI on a 3-T scanner. All ccRCCs were classified as grade 1-4 according to the Fuhrman classification system. The apparent diffusion coefficient (ADC), fractional anisotropy (FA), mean diffusivity (MD), mean kurtosis (MK), axial kurtosis (Ka) and radial kurtosis (Kr) values were recorded. The differences in DWI and DKI parameters were evaluated by independent-sample t test and a receiver operating characteristic (ROC) analysis was performed. The DeLong test was performed to compare the ROCs.
Compared to normal renal parenchyma, ADC and MD values of ccRCC decreased and MK, Ka, and Kr values increased (p < 0.05). ADC and MD values of ccRCC decreased with the increase in pathological grade, while MK, Ka, and Kr values were increased (p < 0.05). ADC could discriminate G1 vs G3, G1 vs G4, G2 vs G3, G2 vs G4, and G3 vs G4 (p < 0.05) except for G1 vs G2 (p > 0.05). Ka and Kr could discriminate G1 vs G2, G1 vs G3, G1 vs G4, G2 vs G4, and G3 vs G4 (p < 0.05) except for G2 vs G3 (p > 0.05). MD and MK could discriminate G1 vs G2, G1 vs G3, G1 vs G4, G2 vs G3, G2 vs G4, and G3 vs G4 (p < 0.05). The AUC of MK was the highest. The DeLong test showed that there were significant differences regarding ROCs between ADC/MK, ADC/Ka, ADC/Kr in grading G1/G2, and ADC/MK, MK/Ka in grading G3/G4 (p < 0.05).
DKI was superior compared to the mono-exponential mode of DWI in grading ccRCC.
评估扩散峰度成像（DKI）在鉴别肾透明细胞癌（ccRCC）方面的作用，与标准扩散加权成像（DWI）进行比较。
对 89 例经组织学证实的 ccRCC 患者在 3T 扫描仪上进行 DKI 和 DWI 检查。所有 ccRCC 根据 Fuhrman 分级系统分为 1-4 级。记录表观扩散系数（ADC）、各向异性分数（FA）、平均扩散系数（MD）、平均峰度（MK）、轴向峰度（Ka）和径向峰度（Kr）值。采用独立样本 t 检验比较 DWI 和 DKI 参数的差异，并进行受试者工作特征（ROC）分析。采用 DeLong 检验比较 ROC。
与正常肾实质相比，ccRCC 的 ADC 和 MD 值降低，MK、Ka 和 Kr 值升高（p<0.05）。ccRCC 的 ADC 和 MD 值随病理分级的增加而降低，而 MK、Ka 和 Kr 值升高（p<0.05）。ADC 可鉴别 G1 与 G3、G1 与 G4、G2 与 G3、G2 与 G4 和 G3 与 G4（p<0.05），但 G1 与 G2 除外（p>0.05）。Ka 和 Kr 可鉴别 G1 与 G2、G1 与 G3、G1 与 G4、G2 与 G4 和 G3 与 G4（p<0.05），但 G2 与 G3 除外（p>0.05）。MD 和 MK 可鉴别 G1 与 G2、G1 与 G3、G1 与 G4、G2 与 G3、G2 与 G4 和 G3 与 G4（p<0.05）。MK 的 AUC 最高。DeLong 检验显示，在 G1/G2 分级中，ADC/MK、ADC/Ka、ADC/Kr 的 ROC 之间，以及在 G3/G4 分级中，ADC/MK、MK/Ka 的 ROC 之间存在显著差异（p<0.05）。
与单指数 DWI 模式相比，DKI 更有助于对 ccRCC 进行分级。
