Validation of Computational Blood Clot Elastometry Model Through Design and Testing of Magnetomotive Ultrasound Tissue-Mimicking Phantoms

Heart disease is the leading cause of death in the United States, with a significant percentage of these deaths being related to complications from blood clots. Although ultrasound can approximate the compressive stiffness (Young's modulus) of clots as a proxy for their age, a quantitative elastometry technique may be valuable for making clinical treatment decisions. Contrast-enhanced Magnetomotive Ultrasound (MMUS) coupled with a finite element model is currently under study as a possible solution. Using COMSOL Multiphysics, we designed a computational elastometry model of a clot submerged in a blood-like fluid and found the resonance frequencies of clinically relevant clot geometries. To validate our model, we designed blood clot-mimicking phantoms by setting gelatin in 3D printed molds and quantitatively measured Young's modulus using MMUS resonance frequency analysis. The resonance frequency that we measured for each shape agreed within one standard deviation and no more than 11% error with the computational model for the same geometry and was sufficiently precise to allow for differentiation among stiffnesses. This indicates that our computational model is realistic and may therefore allow us to detect Young's moduli with MMUS for a wide range of realistic blood clots.