The aim of the Medical Imaging Interaction Toolkit (MITK) is to facilitate the creation of clinically usable image-based software. Clinically usable software for image-guided procedures and image analysis require a high degree of interaction to verify and. if necessary correct results from semi-automatic algorithms. MITK is a class library basing on and extending the Insight Toolkit (ITK) and the Visualization Toolkit (VTK). ITK provides, leading-edge registration and segmentation algorithms and forms the algorithmic basis. VTK has powerful visualization capabilities, but only low-level. support for interaction (like picking methods, rotation, movement and scaling of objects). MITK adds support for high level interactions with data like, for example, the interactive construction and modification of data objects. This includes concepts for interactions with multiple states as well as undo-capabilities. Furthermore, VTK is designed to create one kind of view on the data (either one 2D visualization or a 3D visualization). MITK facilitates the realization of multiple, different views oil the same data (like multiple, multiplanar reconstructions and a 3D rendering). Hierarchically structured combinations of any number and type of data objects (image. surface. vessels, etc.) are possible. MITK can handle 3D+t data, which are required for several important medical applications. whereas VTK alone supports only 2D and 3D data. The benefit of MITK is that it supplements those features to ITK and VTK that are required for convenient to use, interactive and by that clinically usable image-based software, and that are outside the scope of both. MITK will be made open-source (http:// www.mitk.org).
