Comparison of finite elements model elastograms and IVUS elastograms acquired from phantoms and arteries

Knowledge of the Young´s modulus distribution of an atherosclerotic artery allows for differentiation between its components. Intravascular elastography generates an artifactual image of this Young´s modulus distribution. A finite element model (FEM) can assist in interpreting the elastogram and give its Young´s modulus distribution by inverse problem solution. Intravascular ultrasound (IVUS) measurements were performed on a hard phantom with soft eccentric plaque and an atherosclerotic coronary artery. The complex FEM geometry and Young´s modulus distribution were defined using a custom-made graphical user interface. Next elastograms were calculated from IVUS data and compared with FEM elastograms. IVUS and FEM elastograms showed excellent agreement in case of the phantom and a similar pattern in case of the artery. Strain values in the FEM elastogram appeared highly sensitive for variations in the Young´s modulus but not in the Poisson´s ratio.