Mechanical properties of porcine brain tissue in vivo and ex vivo estimated by MR elastography

Charlotte A Guertler; Ruth J Okamoto; John L Schmidt; Andrew A Badachhape; Curtis L Johnson; Philip V Bayly

doi:10.1016/j.jbiomech.2018.01.016

Mechanical properties of porcine brain tissue in vivo and ex vivo estimated by MR elastography

J Biomech. 2018 Mar 1:69:10-18. doi: 10.1016/j.jbiomech.2018.01.016. Epub 2018 Jan 31.

Authors

Charlotte A Guertler¹, Ruth J Okamoto², John L Schmidt², Andrew A Badachhape³, Curtis L Johnson⁴, Philip V Bayly⁵

Affiliations

¹ Washington University in St. Louis, Mechanical Engineering and Materials Science, United States. Electronic address: charlotte.guertler@wustl.edu.
² Washington University in St. Louis, Mechanical Engineering and Materials Science, United States.
³ Washington University in St. Louis, Biomedical Engineering, United States.
⁴ University of Delaware, Biomedical Engineering, United States.
⁵ Washington University in St. Louis, Mechanical Engineering and Materials Science, United States; Washington University in St. Louis, Biomedical Engineering, United States.

Abstract

The mechanical properties of brain tissue in vivo determine the response of the brain to rapid skull acceleration. These properties are thus of great interest to the developers of mathematical models of traumatic brain injury (TBI) or neurosurgical simulations. Animal models provide valuable insight that can improve TBI modeling. In this study we compare estimates of mechanical properties of the Yucatan mini-pig brain in vivo and ex vivo using magnetic resonance elastography (MRE) at multiple frequencies. MRE allows estimations of properties in soft tissue, either in vivo or ex vivo, by imaging harmonic shear wave propagation. Most direct measurements of brain mechanical properties have been performed using samples of brain tissue ex vivo. It has been observed that direct estimates of brain mechanical properties depend on the frequency and amplitude of loading, as well as the time post-mortem and condition of the sample. Using MRE in the same animals at overlapping frequencies, we observe that porcine brain tissue in vivo appears stiffer than porcine brain tissue samples ex vivo at frequencies of 100 Hz and 125 Hz, but measurements show closer agreement at lower frequencies.

Keywords: Brain tissue stiffness; Magnetic resonance elastography; Porcine brain; Post-mortem tissue changes; Shear modulus.

Publication types

Research Support, N.I.H., Extramural
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Animals
Biomechanical Phenomena
Brain / diagnostic imaging*
Elasticity Imaging Techniques*
Magnetic Resonance Imaging*
Mechanical Phenomena*
Models, Theoretical
Swine*
Swine, Miniature

Abstract

Publication types

MeSH terms

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