In medical imaging, segmentation is an important step for many visualization tasks and image-guided procedures. Except for very rare cases, automatic segmentation methods cannot guarantee to provide the correct segmentation. Therefore, for clinical usage, physicians insist on full control over the segmentation result, i.e., to verify and interactively correct the segmentation (if necessary). Display and interaction in 2D slices (original or multi-planar reformatted) are more precise than in 3D visualizations and therefore indispensable for segmentation, verification and correction. The usage of slices in more than one orientation (multi-planar reformatted slices) helps to avoid inconsistencies between 2D segmentation results in neighboring slices. For the verification and correction of three-dimensional segmentations as well as for generating a new 3D segmentation, it is therefore desirable to have a method that constructs a new or improved 3D segmentation from 2D segmentation results. The proposed method enables to quickly extend segmentations performed on intersecting slices of arbitrary orientation to a three-dimensional surface model by means of interpolation with specialized Coons patches. It can be used as a segmentation tool of its own as well as for making more sophisticated segmentation methods (that need an initialization close to the boundary to detect) feasible for clinical routine.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.