Matthew Mcgarry1, Adam Pattison1, Elijah van Houten2, Curtis Johnson3, Bradley Sutton3, John Georgiadis3, John Weaver4, Keith Paulsen1, 4
1Thayer School of Engineering, Dartmouth College, Hanover, NH, United States; 2Universit de Sherbrooke, Sherbrooke, QC, Canada; 3University of Illinois at Urbana-Champaign, Urbana, IL, United States; 4Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
The applicability of using viscoelastic and poroelastic material models as a basis for MR elastography (MRE) reconstruction algorithms is investigated for two variants of in vivo brain MRE: Standard external actuation, where motion is provided at ~50Hz by an external source, and intrinsic actuation, where motion from the natural pulsatility of the brain due to the cardiac pressure cycle is measured and used to calculate the stiffness distribution. Numerical experiments using viscoelastic and poroelastic finite element models offer an explanation for the observed performance of MRE using each of the two material models for each actuation type.