SPM does not actually do the renderings from a proper brain image, but instead
simply superimposes the results on to some pre-rendered views stored in the
file `render.mat'. In order to superimpose your results on to an individuals
brain, you need to create a `render.mat' file for that subject.
There is a hidden function in the SPM96 release for doing this. Unfortunately
it only works for 8 bit images, and you may need to do a bit of pre-processing
on the data. You will need a scalp edited MR image - or an image that can be
thresholded to define what can be considered as brain (so you may be able to
make up some kind of an image using the `Segment' button, and then do a bit
of post processing). The image should be spatially normalized, with a voxel
size of about 1x1x1mm, and it should have either it's ORIGIN field in the
header preserved - or it's `.mat' file. A little bit of smoothing of the
image (say about 3mm FWHM) sometimes helps a bit.
You can call the function from Matlab something like:
spm_renviews('brain.img',0.5);
The rendering function in SPM picks up and uses the first render.mat file
in the MATLABPATH.
I hope this helps,
-John
> This is Jeng-Ren Duann from Lab Functional Brain Imaging, Veterans General
> Hospital - Taipei. We now want to render the statistical result of fMRI onto
> the individual brain. How can we prepare the 3-dimensional brain map from
> anatomical data set and incorporate it into SPM for data rendering? Which
> image file does SPM use to render the statistical results (I mean that the
> image file used when we use "Render" function to render the statistical
> results onto the 3D template brain map)? Can we just replace the image file
> with that we create from the individual anatomical image data set?
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