A new application for displaying and fusing multimodal data sets

A recently developed, freely available, application specifically designed for the visualization of multimodal data sets is presented. The application allows multiple 3D data sets such as CT (x-ray computer tomography), MRI (magnetic resonance imaging), PET (positron emission tomography), and SPECT (single photon emission tomography) of the same subject to be viewed simultaneously. This is done by maintaining synchronization of the spatial location viewed within all modalities, and by providing fused views of the data where multiple data sets are displayed as a single volume. Different options for the fused views are provided by plug-ins. Plug-ins typically used include color-overlays and interlacing, but more complex plug-ins such as those based on different color spaces, and component analysis techniques are also supported. Corrections for resolution differences and user preference of contrast and brightness are made. Pre-defined and custom color tables can be used to enhance the viewing experience. In addition to these essential capabilities, multiple options are provided for mapping 16-bit data sets onto an 8-bit display, including windowing, automatically and dynamically defined tone transfer functions, and histogram based techniques. The 3D data sets can be viewed not only as a stack of images, but also as the preferred three orthogonal cross sections through the volume. More advanced volumetric displays of both individual data sets and fused views are also provided. This includes the common MIP (maximum intensity projection) both with and without depth correction for both individual data sets and multimodal data sets created using a fusion plug-in.