Calculation of Shear Stiffness in Noise Dominated Magnetic Resonance Elastography (MRE) Data Based on Principal Frequency Estimation.

Kiaran Patrick McGee¹, David Lake¹, Yogesh Mariappan¹, Armando Manduca¹, Rolf Hubmayr², Richard Ehman¹

A method for calculating the shear stiffness from magnetic resonance elastography data under conditions of low signal-to-noise ratio (SNR) is described. It is based on the analysis of the spectral content of the propagating shear wave field from which the principal spatial frequency is identified and ultimately shear stiffness calculated. Finite element simulations and ex vivo lung experiments were performed to evaluate the sensitivity of this approach in comparison to the local frequency estimation (LFE) method. Results indicate that principal frequency analysis accurately estimates shear stiffness in comparison to commonly applied LFE-based estimates under low SNR conditions.