TrackVis is a diffusion MRI reconstruction and visualization tool developed by MGH. The output format of TrackVis is *.trk file, containing the coordinates of the generated tracts and related properties or scalars. DSI Studio can load or save *.trk format to offer TrackVis users a way to visualize TrackVis data on DSI Studio.
To load trk file in DSI Studio. First, the diffusion MR images have to be reconstructed into .fib file. Open the fib file, and on the top menu, select a item named "load tracts". A file open dialog will appear, asking the user to open the txt file or trk file that contains the tracts information.
For exporting tract data into .trk file, after the tractography is generated, select "File" -> "Save Tracts As..." and assign a filename with trk as extension. The DSI studio will export a trk file according to the format used by TrackVis. However, so far the exported trk file contains no FA or ADC information. If you are interested in quantitative analysis, the along tract FA can be exported by "File" -> "Save Tract" -> "Nearest FA"