IEEE Trans Biomed Eng. 2019 May;66(5):1456-1467. doi: 10.1109/TBME.2018.2874591. Epub 2018 Oct 8.
To obtain dense spatiotemporal measurements of brain deformation from two distinct but complementary head motion experiments: linear and rotational accelerations.
This study introduces a strategy for integrating harmonic phase analysis of tagged magnetic resonance imaging (MRI) and finite-element models to extract mechanically representative deformation measurements. The method was calibrated using simulated as well as experimental data, demonstrated in a phantom including data with image artifacts, and used to measure brain deformation in human volunteers undergoing rotational and linear acceleration.
Evaluation methods yielded a displacement error of 1.1 mm compared to human observers and strain errors between [Formula: see text] for linear acceleration and [Formula: see text] for rotational acceleration. This study also demonstrates an approach that can reduce error by 86% in the presence of corrupted data. Analysis of results shows consistency with 2-D motion estimation, agreement with external sensors, and the expected physical behavior of the brain.
Mechanical regularization is useful for obtaining dense spatiotemporal measurements of in vivo brain deformation under different loading regimes.
The measurements suggest that the brain's 3-D response to mild accelerations includes distinct patterns observable using practical MRI resolutions. This type of measurement can provide validation data for computer models for the study of traumatic brain injury.
从两个不同但互补的头部运动实验（线性和旋转加速度）中获得大脑变形的密集时空测量结果。
本研究引入了一种策略，将标记磁共振成像（MRI）的谐相分析与有限元模型相结合，以提取具有机械代表性的变形测量结果。该方法使用模拟和实验数据进行了校准，在包括图像伪影的数据的体模中进行了演示，并用于测量经受旋转和线性加速度的人类志愿者的大脑变形。
评估方法与人类观察者相比，位移误差为 1.1 毫米，对于线性加速度为 [Formula: see text]，对于旋转加速度为 [Formula: see text]。本研究还展示了一种在存在损坏数据的情况下可以将误差降低 86%的方法。结果分析表明与 2-D 运动估计一致，与外部传感器一致，以及大脑的预期物理行为一致。
机械正则化对于在不同加载条件下获得活体大脑变形的密集时空测量是有用的。
这些测量结果表明，大脑对轻度加速度的 3-D 反应包括使用实际 MRI 分辨率可以观察到的不同模式。这种类型的测量可以为创伤性脑损伤的计算机模型研究提供验证数据。
