Software tools (Free and some open source)
Medical
Imaging
Repositories
Individual Software Tools
A National Center for Biomedical Computing
Funded under the NIH Roadmap Initiative) 
: Listing of free Medical Imaging Software tools.
3DSlicer
: Segmentation,
registration,
visualization of multi-modal image data, advanced image
analysis algorithms for DTI, fMRI and image-guided therapy. This
software has everything ! 
Brainvisa: 3D image visualization, dedicated
processing for brain
SPM:
Statistical Parametric Mapping
of Brain Imaging 
FSL: Brain registration-segmentation with GUI or shell
scripts. Can be easily called from Matlab.
Mipav: Medical
Image Processing, Analysis, and Visualization, for multiple modalities.
Image segmentation, manual tracing,...
MRICron: Image
viewer, superposition with anatomical templates
:
Modular framework for the development of image processing algorithms,
visualization and interaction methods, with a special focus on medical
imaging.
Mango : The Multi-image Analysis
GUI is a viewer for medical research
images.
MedInria:
free collection of softwares developed within the Asclepios
research project. It aims at providing to clinicians state-of-the-art
algorithms dedicated to medical image processing and visualization.
Main algorithms: Log Euclidian, HARDI, Fiber tracking, block matching,
diffeomorphic demons, DTI registration.
MILXView: 3D medical imaging analysis and
visualization platform .
Medical Images & Databases (Free access)
Na-Mic: National Alliance for Medical Image
Computing. A National Center for Biomedical Computing Funded under the NIH Roadmap Initiative.
Liver CT images.
- Medical Image Samples:
Anatomical Models (Free
access)
FEMONUM: Fetal and Mother
Numerical Models 
IRCAD Liver models