Demonstration of concurrent tensile testing and magnetic resonance elastography

Abstract

Magnetic Resonance Elastography (MRE) is a technique used to measure the mechanical properties of soft tissues and has already shown its diagnostic potential for pathologies involving fibrogenesis and neurodegeneration. Experimental investigation of loading during MRE is fairly unexplored and may help to better understand changing mechanical properties in relation to organ function. Tensile testing is a common technique for examining mechanical properties of materials and is used as the simultaneous comparison method with MRE in this study. 3D MRE data was acquired during quasistatic uniaxial tensile loading of an Ecoflex 0010 cylindrical specimen. Individual MRE scans at 1.5, 2.0, and 2.5kHz where performed on engineering strain increments of 20% from 0% to 140% while tensile reaction force was recorded using a load cell attached to an adjustable elongation slide. Tensile stress-strain relation resembled the Fung hyperelastic strain energy model. We observe that the MRE shear storage modulus is related to the state of tensile deformation. This study demonstrates the feasibility of simultaneous tensile testing during MRE and the new design can potentially be used for MRE calibration using pre-tension.