Two novel methods for computing the 3D cardiac midwall

Computation of the cardiac midwall is an important first step in the pipeline for cardiac image analysis. In this paper, we explore two novel techniques that can give a good estimate of the cardiac midwall, and each of these techniques has certain unique advantages and limitations. Laplacian-based mid- wall technique measures the mid-point of the streamlines of the heat equation from the epicardium to the endocardium and uses standard MR images of the heart. The gamma-wall method measures the fiber midwall which is composed of all points where the fiber travels circumferentially about the ventricle and this is determined by exploiting color image processing techniques. This technique requires the use of diffusion tensor MR images in order to determine the fiber orientation for the entire volume. Both techniques are presented using visualizations on diseased and healthy canine dog hearts.