DSI Studio provides useful functions to edit the generated tractography, including "Select", "Delete", and "Cut". Such 3D interactive functions provide users ways to select fibers of interest, exclude false fibers, or even cut the fiber to facilitate analysis.
As shown in the figure to the right, DSI Studio selects the tracks that pass through the "selection plane", which is determined by the location of the mouse down and mouse up position on the screen.
The steps to carry out selection are as follows:
1. select "Edit" -> "Select" or press Ctrl + S
2. Move the cursor to the starting point of selection plane on the screen.
3. Press the left button of the mouse and move the cursor to the ending point of the selection plane.
4. Release the button and the selection will be performed immediately.
As the example shown by the figure to the right, the selection plane will cull the tracks that pass through it. In this case, the corpus callosum will be selected whereas other fiber bundles will be deleted.
If right button is used in step 3, then the tracks selection further consider the angle of the tracks to the selection plane. An incoming angle smaller than 60 degrees is required to select the tracks. This avoids selecting the tracks that are nearly parallel to the selection plane.
Tract deletion is carried out as the same manner except that the selected tracks will be deleted. The deletion can be undone by press Ctrl+Z.
Tract cutting is to cut the selected tracts into two parts. This function is useful in a condition like the users want to analyze only the right corpus callosum. The corpus callosum can be cut into two parts by a sagittally placed selection plane. The right corpus callosum is then selected to perform further analysis.
Another condition to apply tract cutting is that only a section of the fiber bundle is to be analyzed, or the users want to align the fiber bundle. In such case, an interested portion of the fiber bundle can be extracted by track cutting.
*Note that the track cutting cannot be undone.
Track painting offers a way to paint tracks by a assigned color. To perform this task, press Ctrl+P. Assign the painting color and select the tracks (as illustrated above).
You can also use slice position to cut the tracks and visualize the cutting plane. The function is at [Edit][Cut by slices]