I am learning how to use SPM and ISAS to analyze ictal and interictal SPECT. However I am stuck at a point of their tutorial.
In the item 1.2 one has to set the origin for the SPECT image. That is, to pinpoint the anterior commissure. This is a fairly easy task in a MRI, but very hard to do in a SPECT. How am I to find a tiny anatomical area in such a blurry image (like the one below)?
Are there any anatomical references that I should be using in order to find the approximate area for the anterior commissure?
Any help would be greatly appreciated.