Quantitative analysis and visualization of the endocardial and epicardial walls using gated SPECT images

Abstract

Accurate estimation of ventricular volume and motion is very important for cardiac diagnosis and treatment planning. Physicians typically calculate ventricular volume by using a few slice images and simplified equations. Such methods are generally limited by assumptions about ventricular shape particularly when the ventricle is distorted by ischemia or infarction. They also estimate ventricular motion by sequentially examining slice and phase images. However, it doesn't always give the same results. In this paper, we present an efficient double time-varying deformable model to estimate left ventricular volume and mass more accurately and to analyze endocardial and epicardial wall motions separately. At each time step, the model first finds global rigid motions and then tracks local non-rigid motions based on 3-D point sets extracted from the surface of myocardium, which are classified into endocardial or epicardial walls. The reconstructed endocardial and epicardial walls are visualized at the same time or separately and their motions are quantitatively analyzed. Results of application to gated SPECT images are given. Using the presented model, physicians can estimate the volume change over the cardiac cycle more easily and accurately, and evaluate ventricular motions reproducibly and objectively.