PyVE
PyVE is image analysis and visualization environment
PyVE is image analysis and Visualization Environment focused at clinical use. At the core of it there is a powerful viewer for displaying 3D datasets (MRI, PET, CT) based on VTK.
It all comes precompiled allowing painless access to Python (2.x), the ITK toolkit for image analysis, numpy/scipy for numerical calculations, Qt and PyQt4 for the development Graphical User Interfaces. It is what you need for fast prototyping and development of more complex projects.