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.