A Theoretical Performance Assessment Tool for Myocardial Elastography

The main purpose of this paper is to develop a theoretical tool in order to fundamentally characterize the performance of Myocardial elastography and identify the optimal parameters to be used for the more reliable detection of ischemia or infarction. A complete representation of the left-ventricular function throughout an entire cardiac cycle was previously demonstrated through the use of a 3D finite-element analysis (FEA) model. This FEA model together with an ultrasound image formation model is used here in order to test the performance of 2D myocardial elastography at distinct phases of the cardiac cycle and at different states of myocardium, i.e., normal and ischemic, based on in vivo canine data. A previously developed 3D finite-element analysis (FEA) model of a normal canine left ventricle with 80 nodes and 40 elements was used to simulate all main phases of the cardiac cycle. The axial and lateral displacements within multiple image (x-y) planes across the left-ventricular volume were iteratively calculated and corrected to reduce the decorrelation noise. Given the excellent agreement between the FEA solution and the elastographic strains measured in 2D over an entire simulated cardiac cycle, myocardial elastography proves to be a reliable technique for the accurate assessment of the myocardial deformation in 2D at distinct phases of the cardiac cycle as well as detection of the ischemic region. Preliminary in vivo results of a standard short-axis view in a canine myocardium are shown validating the performance assessment using the proposed model