Interpolation of 3-D images based on point matching

Dose calculation in radiotherapy needs equal spacing 3-D image data sets, which can be reconstructed from a sequence of cross-sectional slices (such as X-CT, MRI etc. ). Typically, the spacing between slices is greater than the spacing between points on a slice. To get equal sample spacing in all directions, one usually uses direct linear interpolation method. Unfortunately, linear interpolation makes the images blurred on edge. In this paper, we develop a new interpolation method based on point matching, in which the corresponding is established between points in neighboring slices. Then this correspondence is used to estimate data between the slices by linear interpolation. The method can produce more accurate results than traditional gray-level linear interpolation method.