Department of Diagnostic and Interventional Neuroradiology, Eberhard Karls University, Hoppe Seyler Str. 3, 72076, Tübingen, Germany,
Neuroradiology. 2013 Oct;55(10):1189-96. doi: 10.1007/s00234-013-1229-7. Epub 2013 Jul 14.
The purpose of this study was to evaluate the feasibility of intravoxel incoherent motion (IVIM) imaging and its value in differentiating the histologic grade among human gliomas.
The IVIM model generated parametric images for apparent diffusion coefficient ADC, slow diffusion coefficient D (or D slow), fast diffusion coefficient D* (or D fast), and fractional perfusion-related volume f in 22 patients with gliomas (WHO grade II-IV) using monopolar Stejskal-Tanner diffusion-weighted imaging (DWI) scheme and 14 b values ranging from 0 s/mm2 to a maximum of 1,300 s/mm2. A region-of-interest analysis on the tumor as well as in the white matter was conducted. The parameter values were tested for significant differences. The repeatability of the measurements was tested by coefficient of variation and Bland-Altman plots.
D, D*, and f in the high-grade gliomas demonstrated significant differences compared to the healthy white matter. D* and f showed a significant difference between low- and high-grade gliomas. D tended to be slightly lower in the WHO grade II compared to WHO grade III-IV tumors. f and D* demonstrated higher coefficients of variation than the ADC and D in tumor. The Bland-Altman plots demonstrated satisfactory results without any outliers outside the mean ± 1.96 standard deviation.
The IVIM-fitted post-processing of DWI-signal decay in human gliomas could show significantly different values of fractional perfusion-related volume and fast diffusion coefficient between low- and high-grade tumors, which might enable a noninvasive WHO grading in vivo.
本研究旨在评估体素内不相干运动（IVIM）成像的可行性及其在区分人类脑胶质瘤组织学分级中的价值。
使用单极 Stejskal-Tanner 扩散加权成像（DWI）方案和 14 个 b 值（范围从 0 s/mm2 到 1,300 s/mm2），对 22 例脑胶质瘤（WHO 分级 II-IV）患者进行 IVIM 模型生成参数图像，包括表观扩散系数 ADC、慢扩散系数 D（或 D slow）、快扩散系数 D*（或 D fast）和灌注相关分数 f。对肿瘤和白质进行感兴趣区分析。对参数值进行显著性检验。通过变异系数和 Bland-Altman 图测试测量的重复性。
高级别胶质瘤的 D、D和 f 与正常白质相比有显著差异。低级别和高级别胶质瘤之间的 D和 f 有显著差异。与 WHO 分级 III-IV 肿瘤相比，WHO 分级 II 肿瘤的 D 略低。f 和 D*在肿瘤中的变异系数高于 ADC 和 D。Bland-Altman 图显示结果令人满意，无任何均值±1.96 标准差外的离群值。
DWI 信号衰减的 IVIM 拟合后处理可在低级别和高级别肿瘤之间显示出明显不同的灌注相关分数和快扩散系数值，这可能使在体进行非侵入性的 WHO 分级成为可能。
