Department of Radiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China.
J Magn Reson Imaging. 2017 Aug;46(2):550-556. doi: 10.1002/jmri.25556. Epub 2016 Nov 30.
To evaluate the feasibility of intravoxel incoherent motion (IVIM) for the measurement of diffusion and perfusion parameters in hyperacute strokes.
An embolic ischemic model was established with an autologous thrombus in 20 beagles. IVIM imaging was performed on a 3.0 Tesla platform at 4.5 h and 6 h after embolization. Ten b values from 0 to 900 s/mm were fitted with a bi-exponential model to extract perfusion fraction f, diffusion coefficient D, and pseudo-diffusion coefficient D*. Additionally, the apparent diffusion coefficient (ADC) was calculated using the mono-exponential model with all the b values. Statistical analysis was performed using the pairwise Student's t test and Pearson's correlation test.
A significant decrease in f and D was observed in the ischemic area when compared with those in the contralateral side at 4.5 h and 6 h after embolization (P < 0.01 for all). No significant difference was observed in D* between the two sides at either time point (P = 0.086 and 0.336, respectively). In the stroke area, f at 6 h was significantly lower than that at 4.5 h (P = 0.016). A significantly positive correlation was detected between ADC and D in both stroke and contralateral sides at 4.5 h and 6 h (P < 0.001 for both). Significant correlation between ADC and f was only observed in the contralateral side at 4.5 h and 6 h (P = 0.019 and 0.021, respectively).
IVIM imaging could simultaneously evaluate the diffusion and microvascular perfusion characteristics in hyperacute strokes.
2 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:550-556.
评估体素内不相干运动（IVIM）测量超急性卒中扩散和灌注参数的可行性。
在 20 只比格犬中建立了自体血栓栓塞性缺血模型。栓塞后 4.5 h 和 6 h ，在 3.0 T 平台上进行 IVIM 成像。用双指数模型拟合 0 到 900 s/mm 的 10 个 b 值，提取灌注分数 f 、扩散系数 D 和假性扩散系数 D*。此外，还使用所有 b 值的单指数模型计算表观扩散系数（ADC）。采用配对学生 t 检验和 Pearson 相关检验进行统计学分析。
栓塞后 4.5 h 和 6 h ，与对侧相比，缺血区 f 和 D 显著降低（所有 P<0.01）。在两个时间点，双侧 D* 无显著差异（分别为 P=0.086 和 0.336）。在卒中区，6 h 的 f 显著低于 4.5 h 的 f （P=0.016）。在 4.5 h 和 6 h ，无论是在卒中区还是在对侧，ADC 与 D 均呈显著正相关（均 P<0.001）。仅在 4.5 h 和 6 h 时，ADC 与 f 在对侧存在显著相关性（分别为 P=0.019 和 0.021）。
IVIM 成像可同时评估超急性卒中的扩散和微血管灌注特征。
2 技术疗效：1 级。J. MAGN. RESON. IMAGING 2017；46：550-556。
