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devel > meaning of coordinates
Jan 12, 2011 02:01 PM | Richard Reynolds
meaning of coordinates
Hi All,
I kept forgetting to bring this up, but I think we are missing an important piece of the transformation matrices, that being what the coordinates actually mean. For example (-24, -6, -16) might mean the left amygdala in Talairach space. Or it could mean the right parahippocampal gyrus, even in Talairach space. Does the -24 mean 24L? 24R? 24I?
It would be sufficient (and probably prudent) to say that we follow the coordinate definition from NIfTI, which describes coordinates as being L->R (negative to positive), P->A (- to +), I->S (- to +). Following this convention, the (-24, -6, -16) example would mean 24L, 6P, 16I, which would be in the left amygdala (when using the Talairach template space).
Does that seem reasonable to everyone? If so, it should be in the documentation. Maybe it is and I have just completely missed it. If so, uh, never mind...
- rick
I kept forgetting to bring this up, but I think we are missing an important piece of the transformation matrices, that being what the coordinates actually mean. For example (-24, -6, -16) might mean the left amygdala in Talairach space. Or it could mean the right parahippocampal gyrus, even in Talairach space. Does the -24 mean 24L? 24R? 24I?
It would be sufficient (and probably prudent) to say that we follow the coordinate definition from NIfTI, which describes coordinates as being L->R (negative to positive), P->A (- to +), I->S (- to +). Following this convention, the (-24, -6, -16) example would mean 24L, 6P, 16I, which would be in the left amygdala (when using the Talairach template space).
Does that seem reasonable to everyone? If so, it should be in the documentation. Maybe it is and I have just completely missed it. If so, uh, never mind...
- rick
Threaded View
| Title | Author | Date |
|---|---|---|
| Richard Reynolds | Jan 12, 2011 | |
| John Harwell | Jan 12, 2011 | |
| Richard Reynolds | Jan 12, 2011 | |
| John Harwell | Jan 14, 2011 | |
