Check your default voxel sizes for writing spatially normalized files
(click on defaults, select spatial normalization, then select defaults
for writing normalized). I think the default set for spm2 is 2x2x2; the
defaults for spm99 (i don't recall) were probably 3x3x3: 3x3x3/2x2x2 =
27/8 = 3.375, which is about the factor that your file sizes are off.
Regards,
Jejo
Valera, Eve M. wrote:
> Hello,
> We've been having some problems with file sizes during the
> preprocessing steps in SPM2. When run in SPM99, our nr* file sizes
> are "normal": 307,188. Using the same data in SPM2, the wr* file
> sizes are significantly larger: 1,035,690. This is causing a drastic
> increase in our usage of our disk space and it seems that this is an
> error - though we do not get any error messages. Can anyone help us
> to understand why the file sizes are so much larger, and if there is a
> way to ensure that they are the same size as the files analyzed in
> SPM99? We've tried running realignment in SPM2, normalization in
> SPM99, then smoothing and models in SPM2 again, but aren't sure if
> this is totally legit. Is it ok to do things this way (using both
> SPM2 and SPM99 for preprocessing) at least until we get this file size
> issue figured out? Any help would be greatly appreciated! Thank you!
>
> Nicole Peace
> Harvard Medical School
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