Dear Dan,
If you created the ROI mask based on the same subject(s) anatomical
scan, then you may be able to get away with an affine transform to align
the functional scan to the anatomical (unless your anatomical was
already in-plane with the same slice prescription == ideal). In SPM, you
can use the S.V.C. tool (for small volume correction) and your ROI masks
to get statistics relevant only to the specified region. Another
alternative is to use the MarsBar to carry out the ROI analysis using
your mask.
Hope this helps.
Best,
Mike
Dan Krainak wrote:
> Hello SPM-listserv,
>
> I am a graduate student trying to determine the activation in and around
> the motor cortices for an event-related study. I have already performed
> a total brain analysis with SPM2. I have also created a ROI mask around
> the motor cortices in MRIcro based on anatomical markers. How do I
> multiply this mask with my functional images in order to run SPM only on
> the motor cortices? The process should be similar to removing a lesioned
> area prior to estimating activations. I would prefer to do this without
> normalizing the data to stereotaxic space. Is there existing software
> that allows me to do this with SPM?
>
> Thanks,
>
> Dan Krainak
>
--
______________________________________________________________________
| Michael A. Yassa, B.A. |
| ____ ______ __ |
| ( _ )( __ )( ) Division of Psychiatric Neuroimaging |
| ) __) )( )( )( Department of Psychiatry and Behavioral Sciences|
| (__) (__)(__)(__) The Johns Hopkins University School of Medicine |
| 600 North Wolfe Street, Phipps 322, Baltimore MD 21287 |
| Tel: 410-955-7861, Fax: 410-614-3676, E-mail: [log in to unmask] |
| Web: http://pni.med.jhu.edu |
|_____________________________________________________________________|
|