Hi. Just to contribute to this conversation...In our lab, we align the anatomical image to the epi data, rather than epi data to the anatomical image. This approach avoids an additional resampling, or interpolation of the epi data--thereby, increasing the power of your results.
Hope this is helpful.
Christine
________________________________________
From: SPM (Statistical Parametric Mapping) [[log in to unmask]] on behalf of Jonathan Peelle [[log in to unmask]]
Sent: Thursday, December 15, 2011 7:57 AM
To: [log in to unmask]
Subject: Re: [SPM] Difference between two normalization approaches
Dear Shilpi Modi,
> This might sound to be a very basic question but I would like to know what
> is the difference between 'normalization to EPI template' and 'normalization
> with the parameter file generated after segmentation step (as given in
> example data set of SPM8 manual)' ?
>
> Which option should be used?
>
> If I use the later option doesn't it mean that, I am actually not
> normalizing all the subjects to a common template?
In both cases you are normalizing subjects to a common space (MNI
space). The difference is whether you use the functional (EPI) images
to do so, or the structural image (via segmentation).
I would guess that most people use the parameter files generated
during segmentation. However, in some cases—particularly if your EPI
images are fairly distorted—directly normalizing to the EPI template
may work better. I'm not aware of any systematic comparison between
the two, so it's hard to say which is "best" (and that probably
depends on the situation).
Hope this helps!
Best regards,
Jonathan
--
Dr. Jonathan Peelle
Department of Neurology
University of Pennsylvania
3 West Gates
3400 Spruce Street
Philadelphia, PA 19104
USA
http://jonathanpeelle.net/
The information in this transmission is intended for official use of the Kessler Foundation. It is intended for the exclusive use of the persons or entities to which it is addressed. If you are not an intended recipient or the employee or agent responsible for delivering this transmission to an intended recipient, be aware that any disclosure, dissemination, distribution or copying of this communication, or the use of its contents, is strictly prohibited. If you received this transmission in error, please notify the sender by return e-mail and delete the material from any computer.
|