1.5 Creation of a Volume Diffusion Weighted (VDW) data set

We will now create a VDW data set, using the files created during the co-registration phase. The procedure is quite similar to the VTC creation in fMRI data analysis.

Go to DTI --> Create 3D-Aligned Diffusion Weighted (VDW)
Data. A window appears: Use the Browse button to locate the DMR file human31dir.dmr. Next, locate all necessary files for VDW creation. The window should now look similar to this:


Next, go to the Options window and check whether Sinc interpolation at Interpolation options is activated. DWI data is extremely sensitive to interpolation, so the best interpolation setting is required. However, sinc interpolation may easily take hours to compute, so if you don’t have that time, take the next best option, which is Trilinear. The rest may be left as default. You may choose to turn on or change the Use intensity threshold to find brain voxels, but this is not recommended. Use masking, see section 1.6.3 instead.


Click Ok and GO in the VDW File Creation window.