1.7 Tensor visualization

After performing all steps until calculation of the tensors (DDT file creation), the tensors can be visualised in 3D space. Open human.vmr and load the DDT file human31dir_vdw.dmr via DTI --> Diffusion Weighted Data Analysis --> Browse. Close this window and go to DTI --> Tensor Visualisation. A new main window opens and the tensor data is visualised as color coded lines. Color coding is identical to that of a FA/MD direction color coded map. The lines represent the major direction of the diffusion tensor. You may want to adjust the amount of visible tensors by de- or increasing the FA threshold.


Show Tensors

check/uncheck to show/hide tensors

Show current mesh

check/uncheck to show/hide a mesh

Perspective view

check/unchek to view data in perspective or not in perspective. Also activated by pressing P on your keyboard.


FA threshold for tensor display. High threshold few tensors and vice versa

Slice plane restriction

show only tensors limited to a slice plane, within a certain distance in mm from a slice. See text for instructions.

You can navigate in 3-D space using the following gestures:

gesture effect

hold left + move mouse rotation
hold right + move mouse translation
hold left + right + move mousezoom

The tensor view may also be limited to a slice instead of the whole volume. First, display one or more slices by clicking or (Shift)-clicking one of the “cut”-buttons listed below. Brainvoyager will show you the selected slice, and by checking the Slice plane
restriction box, the tensors will be limited to the slice(s) selected. You can move the slices by the Alt+hold left click+move mouse key combination. In figure 1.6.b the view is shown.

Transversal slice cutSagittal slice cutCoronal slice cut

(a) Tensors in the whole volume. FA > 0.6.
(b) Tensors limited to a sagittal and transversal plane. FA > 0.20
Figure 1.6: Tensor viewing options