Reslicing axially sampled 3D shapes using elliptic Fourier descriptors.

We propose a new method that interpolates between parallel slices from a 3D shape for the purposes of reslicing and putting into correspondence organ shapes acquired from volumetric medical imagery. By interpolating the coefficients of elliptic Fourier descriptors for a set of parallel contours, a new set of slices can be directly generated at desired axial locations. Neither an explicit correspondence between points on adjacent contours nor a 3D interpolating surface needs to be obtained. We apply the proposed reslicing method to experimental datasets of both synthetic 3D shapes and real prostate contours, and demonstrate that it performs as well as a common method based on variational implicit surfaces, for a much lower computational cost. We also show that reslicing and putting into correspondence an ensemble of axially sampled 3D organs enables the construction of shape models for accurate 3D segmentation.