The 3D Slicer uniquely integrates several facets of image-guided medicine into a single environment. It provides capabilities for automatic registration (aligning data sets), semi-automatic segmentation (extracting structures such as vessels and tumors from the data), generation of 3D surface models (for viewing the segmented structures), 3D visualization, and quantitative analysis (measuring distances, angles, surface areas, and volumes) of various medical scans.
The 3D Slicer is freely available and provided as open source software. Its design is fully modular to encourage researchers to extend its functionality. It's new home is at www.slicer.org