Testu J, McGarry M D J, Dittmann F, Weaver J B, Paulsen K D, Sack I, Van Houten E E W
Department of Mechanical Engineering, University of Sherbrooke, Sherbrooke, Québec, Canada J1L 2R1.
Department of Biomedical Engineering, Columbia University, New York, NY 10032, United States.
J Mech Behav Biomed Mater. 2017 Oct;74:333-341. doi: 10.1016/j.jmbbm.2017.06.027. Epub 2017 Jun 21.
The noninvasive imaging technique of magnetic resonance elastography (MRE) was used to estimate the power law behavior of the viscoelastic properties of the human brain in vivo. The mechanical properties for four volunteers are investigated using shear waves induced over a frequency range of 10-50Hz to produce a displacement field measured by magnetic resonance motion-encoding gradients. The average storage modulus (μ) reconstructed with non-linear inversion (NLI) increased from approximately 0.95 to 2.58kPa over the 10-50Hz span; the average loss modulus (μ) also increased from 0.29 to 1.25kPa over the range. These increases were modeled by independent power law (PL) relations for μ and μ returning whole brain, group mean exponent values of 0.88 and 1.07 respectively. Investigation of these exponents also showed distinctly different behavior in the region of the cerebral falx compared to other brain structures.
磁共振弹性成像（MRE）这种非侵入性成像技术被用于在体内估计人脑粘弹性特性的幂律行为。使用在10 - 50Hz频率范围内产生的剪切波来研究四名志愿者的力学特性，以产生由磁共振运动编码梯度测量的位移场。通过非线性反演（NLI）重建的平均储能模量（μ）在10 - 50Hz范围内从约0.95kPa增加到2.58kPa；平均损耗模量（μ）在该范围内也从0.29kPa增加到1.25kPa。这些增加通过μ和μ的独立幂律（PL）关系进行建模，回归全脑时，组平均指数值分别为0.88和1.07。对这些指数的研究还表明，与其他脑结构相比，大脑镰区域的行为明显不同。
