Device for segmenting an image, comprising a first and at least one second image slice, of a subject in medical imaging, comprising: - a data interface for receiving a first image slice of said subject, said first image slice depicting an anatomical structure of said subject; - a translation unit for translating a user-initiated motion of an image positioner means into a first contour surrounding said anatomical structure; - a motion parameter registering unit for registering a motion parameter of said user-initiated motion to said first contour, said motion parameter comprising a speed and/or an acceleration of said image positioner means; - an image control point unit for distributing a plurality of image control points on said first contour with a density decreasing with said motion parameter; and - a segmentation unit for segmenting said first image slice by determining a second contour within said first contour based on said plurality of image control points, said segmentation unit being configured to use one or more segmentation functions; wherein said segmentation unit is configured to identify a plurality of target points within said first contour, said target points lying each within a path beginning at a corresponding one of said image control points, said second contour being formed by connecting said plurality of target points; and wherein said path comprises a straight path, said straight path being perpendicular or oblique to an edge of said first contour and having a length increasing with said motion parameter; a transferring unit for transferring said second contour from said first to said at least one second image slice; wherein said device is further configured to predict a third contour in the second image slice based on the transferred second contour, wherein said image control point unit is further configured to distribute a plurality of additional image control points without using said motion parameter and wherein the path corresponding to the additional image control points comprises a length correlated with a curvature of the second contour. - a data interface for receiving a first image slice of said subject, said first image slice depicting an anatomical structure of said subject; - a translation unit for translating a user-initiated motion of an image positioner means into a first contour surrounding said anatomical structure; - a motion parameter registering unit for registering a motion parameter of said user-initiated motion to said first contour, said motion parameter comprising a speed and/or an acceleration of said image positioner means; - an image control point unit for distributing a plurality of image control points on said first contour with a density decreasing with said motion parameter; and - a segmentation unit for segmenting said first image slice by determining a second contour within said first contour based on said plurality of image control points, said segmentation unit being configured to use one or more segmentation functions; wherein said segmentation unit is configured to identify a plurality of target points within said first contour, said target points lying each within a path beginning at a corresponding one of said image control points, said second contour being formed by connecting said plurality of target points; and wherein said path comprises a straight path, said straight path being perpendicular or oblique to an edge of said first contour and having a length increasing with said motion parameter; a transferring unit for transferring said second contour from said first to said at least one second image slice; wherein said device is further configured to predict a third contour in the second image slice based on the transferred second contour, wherein said image control point unit is further configured to distribute a plurality of additional image control points without using said motion parameter and wherein the path corresponding to the additional image control points comprises a length correlated with a curvature of the second contour.