Shape representation of human anatomy using spherical harmonic basis function

In medical imaging research, the three-dimensional (3-D) shape representation and analysis of anatomic structures using only a few parameters is an important issues, and can be applied to computer assisted diagnosis, surgical simulations, visualization, and many other medical applications. This paper proposes the representation of the shape surfaces of a simply connected 3-D object using spherical harmonic (spharm) functions, which can provide an approximate global description of the shape using only a few spharm parameters. Spharms are obtained from several partial differential equations used in physics, such as the Laplace, Helmholtz, and Schrodinger equations, in which spherical coordinates are used. In this study, we aim to develop a 3D representation of human anatomy, such as the liver and spleen, with fewer parameters by using spharm functions. Furthermore, the experimental results show that the shape of the liver and spleen can be accurately represented with only a few spharm parameters.