Comparison of Monoexponential, Biexponential, Stretched-Exponential, and Kurtosis Models of Diffusion-Weighted Imaging in Differentiation of Renal Solid Masses
Comparison of Monoexponential, Biexponential, Stretched-Exponential, and Kurtosis Models of Diffusion-Weighted Imaging in Differentiation of Renal Solid Masses
复制标题
扩散加权成像的单指数、双指数、拉伸指数和峭度模型在肾脏实性肿块鉴别中的比较
DOI：
10.3348/kjr.2018.0474
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发表时间：
2019-05-01
影响因子：
4.8
通讯作者：
Wu，Guangyu
中科院分区：
文献类型：
--
作者：
Zhang，Jianjian;Suo，Shiteng;Wu，Guangyu
目的比较单指数表观扩散系数（ADC）、双指数（快扩散系数[Df]、慢扩散系数[Ds]和快扩散分数）、拉伸指数（分布扩散系数和异常指数项[α]）和峰度（平均扩散系数和平均峰度[MK]）模型在肾实质性肿块鉴别诊断中的作用。材料与方法81例（男56例，女25例;年龄30-69岁，平均57岁）良性病变18例，恶性病变63例。使用Akaike信息标准在每个病变中研究扩散模型选择。采用Mann-Whitney U检验和受试者工作特征（ROC）分析进行统计学评价。结果拟合优度分析显示，拉伸指数模型在良恶性病变中的体素比例最高（分别为90.7%和51.4%）。ADC、Ds和MK在良性病变与恶性病变之间（p < 0.05）以及在低级别透明细胞肾细胞癌（ccRCC）与高级别透明细胞肾细胞癌之间（p < 0.05）显示出显著差异。良性组α值明显低于恶性组（P < 0.05）。除Df和α（分别为p = 0.143和0.112）外，ccRCC和非ccRCC之间的所有扩散指标均显示出显着差异（p < 0.05）。α在区分良恶性病变方面显示出最高的诊断准确性，ROC曲线下面积为0.923，但这些先进模型的参数在区分肾细胞癌（RCC）的亚型或级别方面均未显示出明显优于ADC的性能（p > 0.05）。结论与常规弥散参数相比，α可为鉴别肾脏良恶性肿块提供更多信息，而ADC仍是鉴别RCC亚型和ccRCC分级最有价值的参数。
Objective To compare various models of diffusion-weighted imaging including monoexponential apparent diffusion coefficient (ADC), biexponential (fast diffusion coefficient [Df], slow diffusion coefficient [Ds], and fraction of fast diffusion), stretched-exponential (distributed diffusion coefficient and anomalous exponent term [α]), and kurtosis (mean diffusivity and mean kurtosis [MK]) models in the differentiation of renal solid masses. Materials and Methods A total of 81 patients (56 men and 25 women; mean age, 57 years; age range, 30–69 years) with 18 benign and 63 malignant lesions were imaged using 3T diffusion-weighted MRI. Diffusion model selection was investigated in each lesion using the Akaike information criteria. Mann-Whitney U test and receiver operating characteristic (ROC) analysis were used for statistical evaluations. Results Goodness-of-fit analysis showed that the stretched-exponential model had the highest voxel percentages in benign and malignant lesions (90.7% and 51.4%, respectively). ADC, Ds, and MK showed significant differences between benign and malignant lesions (p < 0.05) and between low- and high-grade clear cell renal cell carcinoma (ccRCC) (p < 0.05). α was significantly lower in the benign group than in the malignant group (p < 0.05). All diffusion measures showed significant differences between ccRCC and non-ccRCC (p < 0.05) except Df and α (p = 0.143 and 0.112, respectively). α showed the highest diagnostic accuracy in differentiating benign and malignant lesions with an area under the ROC curve of 0.923, but none of the parameters from these advanced models revealed significantly better performance over ADC in discriminating subtypes or grades of renal cell carcinoma (RCC) (p > 0.05). Conclusion Compared with conventional diffusion parameters, α may provide additional information for differentiating benign and malignant renal masses, while ADC remains the most valuable parameter for differentiation of RCC subtypes and for ccRCC grading.