Transversely-isotropic brain in vivo MR elastography with anisotropic damping.
Transversely-isotropic brain in vivo MR elastography with anisotropic damping.
复制标题
DOI：
10.1016/j.jmbbm.2023.105744
复制
发表时间：
2023-03
影响因子：
3.9
通讯作者：
Dhrubo Jyoti;M. McGarry;Diego A. Caban-Rivera;Elijah E W Van Houten;C. Johnson;Keith D. Paulsen
中科院分区：
文献类型：
--
作者：
Dhrubo Jyoti;M. McGarry;Diego A. Caban-Rivera;Elijah E W Van Houten;C. Johnson;Keith D. Paulsen
从日益复杂的机械特性模型中测量组织参数可能会发现具有临床实用性的新对比机制。基于先前关于具有横向各向同性和各向同性阻尼（TI-ID）模型的体内脑磁共振弹性成像（MRE）的工作，我们探索了一种新的横向各向同性和各向异性阻尼（TI-AD）模型，该模型涉及描述刚度和阻尼的方向依赖行为的六个独立参数。机械各向异性的方向由扩散张量成像确定，我们在整个大脑体积内拟合三个复值模量分布，以最大限度地减少测量位移和建模位移之间的差异。我们在理想化的贝壳模型模拟以及 20 个真实的、随机生成的模拟大脑的集合中展示了空间精确的属性重建。我们将主要白质束的所有六个参数的模拟精度描述为很高，这表明它们可以根据 MRE 数据以可接受的精度进行独立测量。最后，我们展示了体内各向异性阻尼 MRE 重建数据。我们对单个受试者进行八次重复的 MRE 大脑检查进行 t 检验，发现大多数脑束、脑叶和整个大脑的三个阻尼参数在统计上是不同的。我们还表明，对于大多数脑束、脑叶和全脑，对于所有六个参数，17 名受试者队列中的群体差异超过了单受试者测量的重复性。这些结果表明 TI-AD 模型提供了可能支持脑部疾病鉴别诊断的新信息。
Measuring tissue parameters from increasingly sophisticated mechanical property models may uncover new contrast mechanisms with clinical utility. Building on previous work on in vivo brain MR elastography (MRE) with a transversely-isotropic with isotropic damping (TI-ID) model, we explore a new transversely-isotropic with anisotropic damping (TI-AD) model that involves six independent parameters describing direction-dependent behavior for both stiffness and damping. The direction of mechanical anisotropy is determined by diffusion tensor imaging and we fit three complex-valued moduli distributions across the full brain volume to minimize differences between measured and modeled displacements. We demonstrate spatially accurate property reconstruction in an idealized shell phantom simulation, as well as an ensemble of 20 realistic, randomly-generated simulated brains. We characterize the simulated precisions of all six parameters across major white matter tracts to be high, suggesting that they can be measured independently with acceptable accuracy from MRE data. Finally, we present in vivo anisotropic damping MRE reconstruction data. We perform t-tests on eight repeated MRE brain exams on a single-subject, and find that the three damping parameters are statistically distinct for most tracts, lobes and the whole brain. We also show that population variations in a 17-subject cohort exceed single-subject measurement repeatability for most tracts, lobes and whole brain, for all six parameters. These results suggest that the TI-AD model offers new information that may support differential diagnosis of brain diseases.