A method (100) for image segmentation in a three-dimensional environment includes receiving scan data (112), selecting a viewing vector relative to the scan data (114), rendering the scan data as a 3D image about the viewing vector (116), displaying the rendered 3D image (118), selecting a range of 2D image slices within the 3D image (122), performing 2D segmentation on the selected slices relative to the viewing vector to obtain a segmented 3D object (124), and displaying the segmented 3D object (128).