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Hello Michael,

Our group has been collecting data for two years and we have been processing it as we go. We noticed the same thing. As we collected data across time, we updated our versions of vbm8. To make sure the new versions were the same as the old, we processed the same data with both versions. The different versions produced different Total Grey Matter /White Matter/ CSF volumes in the text file generated during preprocessing. Additionally, the grey matter segmented image produced was different for the old and new versions.

I am unsure what is changed across the different versions that produces this difference. We chose to process all our data with the same version. Hope this helps.

Adam



On Fri, Jan 27, 2012 at 1:52 PM, Michael <[log in to unmask]> wrote:
Hello,

I've conducted some longitudinal vbm analysis back in spring 2011 with version vbm8_r409. The results looked promising. However, after making the upgrade to vbm_r435, I noticed the same exact analysis i conducted on the same data set yielded different results.  Just to check,  I preprocessed the data set using version 409 and also using 435. So, i'm assuming there is a difference in the preprocessing calculations and this is due to the upgrade(s)?  Has anybody else experienced this?  Your help would greatly be appreciated.

Thanks,

Michael