Delphin Aurélien, Boux Fabien, Brossard Clément, Coudert Thomas, Warnking Jan M, Lemasson Benjamin, Barbier Emmanuel L, Christen Thomas
Univ. Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, GIN, 38000, Grenoble, France.
Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, CNRS, IRMaGe, 38000, Grenoble, France.
Imaging Neurosci (Camb). 2024 Dec 16;2. doi: 10.1162/imag_a_00377. eCollection 2024.
Magnetic resonance (MR) vascular Fingerprinting proposes to use the MR Fingerprinting framework to quantitatively and simultaneously map several characteristics that emerge from vascular structure much smaller than voxel size. The initial implementation assessed the local blood oxygenation saturation (SO), blood volume fraction (BVf), and vessel averaged radius (R) in humans and rodent brains using simple 2D representations of the vascular network during dictionary generation. In order to improve the results and possibly extend the approach to pathological environments and other biomarkers, we propose in this study to use 3D realistic vascular geometries in the numerical simulations. 28,000 different synthetic voxels containing vascular networks segmented from whole-brain healthy mice microscopy images were created. A Bayesian-based regression model was used for map reconstruction. We show in 8 healthy and 9 tumor-bearing rats that realistic vascular representations yield microvascular estimates in better agreement with the literature than 2D or 3D cylindrical models. Furthermore, tumoral blood oxygenation variations observed with the proposed approach are the only ones correlating with in vivo optic-fiber measurements performed in the same animals.
磁共振（MR）血管指纹识别技术旨在利用MR指纹识别框架，对源自远小于体素大小的血管结构的多种特征进行定量和同步映射。最初的实施方案在字典生成过程中，使用血管网络的简单二维表示，评估了人类和啮齿动物大脑中的局部血氧饱和度（SO）、血容量分数（BVf）和血管平均半径（R）。为了改善结果，并可能将该方法扩展到病理环境和其他生物标志物，我们在本研究中建议在数值模拟中使用三维真实血管几何模型。我们创建了28000个不同的合成体素，这些体素包含从全脑健康小鼠显微镜图像中分割出来的血管网络。基于贝叶斯的回归模型用于图谱重建。我们在8只健康大鼠和9只荷瘤大鼠中表明，与二维或三维圆柱形模型相比，真实的血管表示产生的微血管估计值与文献的一致性更好。此外，用所提出的方法观察到的肿瘤血氧变化是与在同一动物中进行的体内光纤测量相关的唯一变化。
