The Display tool in SPM12 has additional function for viewing blobs, DTI images, zooming in and out, and so on.
Accessing Extended Display Options
1) Display an image using the SPM menu button;
2) Type
>>spm_orthviews('addcontext')
Tip: there is a button in the CSPM GUI to do this.
3) Right-click over the image
DTI Color-coded Direction Map
GUI actions by user
Locate the "evec1x/y/z" files
Right-click, and select RGB overlays, Add
First, select three evec1 files
Optionally, select an "FA" file to scale the evec files by
Optionally, select a mask
Display actions
A set of three images will be displayed on top of the existing image, representing red, blue and green. The images are calculated based on the selected files.
The program first calculates the absolute value of the evec files, so you will see "abs_evec1x..." appear.
If an FA image was selected, this will be used to scale the abs_evec maps. Otherwise, the evec files are unchanged.
If a mask file was selected, the images will be masked, indicated by "abs_msk_evec" or "abs_msk_fa_evec".
Tip: to brighten the image, add the RGB 2-3 times. To spped this up, you can pre-multiply the evec1 files by the FA image, and only select those (suggested naming is "fa_evec1").
Background image
The RGB is overlaid onto whatever images was displayed first, which could be a T1, FA, MD, etc. To view only the RGB, select an empty image to display.
Context menu (right-click over displayed image)
Example: evec1x,fa_evec1y,fa_evec1z overlaid onto an FA file, no FA or mask.
Example: evec1x,evec1y,evec1z, with FA, overlaid onto an empty file.