Thinner Regions of Intracranial Aneurysm Wall Correlate with Regions of Higher Wall Shear Stress: A 7T MRI Study.
Thinner Regions of Intracranial Aneurysm Wall Correlate with Regions of Higher Wall Shear Stress: A 7T MRI Study.
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DOI：
10.3174/ajnr.a4734
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发表时间：
2016-07
期刊：
影响因子：
--
通讯作者：
Zwanenburg JJ
中科院分区：
文献类型：
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作者：
Blankena R;Kleinloog R;Verweij BH;van Ooij P;Ten Haken B;Luijten PR;Rinkel GJ;Zwanenburg JJ
建立一种在颅内动脉瘤活体7.0 T MRI图像上半定量评估壁厚的方法，以研究动脉瘤表观壁厚与壁切应力之间的关系。分析了9名患者的11个未破裂动脉瘤的壁厚，这些患者接受了7 T MRI，并采用基于TSE的血管壁序列（0.8 mm各向同性分辨率）。自定义分析程序确定体内动脉瘤壁强度，将其标准化为附近脑组织的信号，并用作表观壁厚度（AWT）的测量。将空间壁厚变化确定为AWT的四分位距（AWT范围的中间50%）。使用相差MRI（0.5 mm各向同性分辨率）测定壁剪切应力。我们进行了视觉和统计比较（皮尔逊相关），以研究壁厚和壁切应力之间的关系。动脉瘤的3D彩色AWT图显示空间AWT变化，范围为0.07 - 0.53，平均变化为0.22（变化1.0大致意味着一个体素（0.8mm）的壁厚变化）。在所有动脉瘤中，AWT与WSS呈负相关（平均相关系数为-0.35，P<0.05）。开发了一种使用7 T MRI半定量测量壁厚的方法。壁面切应力与AWT呈负相关。在未来的研究中，这种非侵入性方法可用于评估与病理生理过程（如动脉瘤生长和破裂）相关的空间壁厚变化。
To develop a method for semi-quantitative wall thickness assessment on in vivo 7.0 tesla (7T) MRI images of intracranial aneurysms for studying the relation between apparent aneurysm wall thickness and wall shear stress. Wall thickness was analyzed in 11 unruptured aneurysms in 9 patients, who underwent 7T MRI with a TSE based vessel wall sequence (0.8 mm isotropic resolution). A custom analysis program determined the in vivo aneurysm wall intensities, which were normalized to signal of nearby brain tissue and were used as measure for apparent wall thickness (AWT). Spatial wall thickness variation was determined as the interquartile range in AWT (the middle 50% of the AWT range). Wall shear stress was determined using phase contrast MRI (0.5 mm isotropic resolution). We performed visual and statistical comparisons (Pearson’s correlation) to study the relation between wall thickness and wall shear stress. 3D colored AWT maps of the aneurysms showed spatial AWT variation, which ranged from 0.07 to 0.53, with a mean variation of 0.22 (a variation of 1.0 roughly means a wall thickness variation of one voxel (0.8mm)). In all aneurysms, AWT was inversely related to WSS (mean correlation coefficient −0.35, P<0.05). A method was developed to measure the wall thickness semi-quantitatively, using 7T MRI. An inverse correlation between wall shear stress and AWT was determined. In future studies, this non-invasive method can be used to assess spatial wall thickness variation in relation to pathophysiologic processes such as aneurysm growth and –rupture.