Analysis of regional deformation of the heart's left ventricle using invariant SPHARM descriptors

This paper presents a method to analyze the regional deformation of the heart left ventricle (LV). It consists of two steps. First, based on previous work a global analysis is carried out in order to detect any pathological cases using 3D spherical harmonic (SPHARM) shape description process. The computed invariant SPHARM shape descriptors are used to compute the distance between the LV anatomical structures namely the endocardium and epicardium. Secondly, to accurately determine the site and the extent of the disease, a regional analysis is achieved. For this purpose, a 3D division into 17 regions’ 3D closed surfaces according to the AHA standard is carried out and a surface closing process is proposed. Each resulting region is then decomposed into a spherical harmonic basis. The regional invariant SPHARM descriptors are generated and used to quantify regional deformations. This method has been validated on deformable surfaces synthesized using an ellipsoidal model and real data obtained from myocardial scintigraphy imaging techniques.