High order slice interpolation for medical images

In this paper we introduce a high order object- and intensity-based method for slice interpolation. Similar structures along the slices are registered using a symmetric similarity measure to calculate displacement fields between neighboring slices. For the intensity-based and curvature-regularized registration no manual landmarks are needed but the structures between two subsequent slices have to be similar. The set of displacement fields is used to calculate a natural spline interpolation for structural motion that avoids kinks. Along every correspondence point trajectory, again high order intensity interpolating splines are calculated for gray values. We test our method on an artificial scenario and on real MR images. Leave-one-slice-out evaluations show that the proposed method improves the slice estimation compared to piecewise linear registration-based slice interpolation and cubic interpolation.