I am using the Analyze 8.1 Region of Interest (ROI) module to define
regions and store them as object maps. I then converted the object maps
into an Analyze 7.5 image and header format because I want to load this ROI
into SPM5 to use as a mask for statistical analyses.
However, when I load this ROI image (along with the MPRAGE volume that
Analyze 8.1 generated from the original DICOM files and on which the
tracings were done) into SPM5 it gets displayed incorrectly. The ROI and
the MPRAGE image that I see in SPM5 are the mirror images of the same ROI
and MPRAGE image that I saw in Analyze 8.1. The ROI is also much bigger in
SPM5 than it ought to be. In SPM5, if I overlay the ROI onto the MPRAGE
volume (originally generated from Analyze 8.1), this ROI mask is no where
near the original structure that it was traced from (e.g. the hippocampal
ROI is not where the hippocampus is on the MPRAGE).
When I displayed this ROI (and overlaid it onto the MPRAGE volume image
generated from Analyze 8.1) using FSL view, everything looks correct (e.g.
FSL does not display the mirror image of what I saw in Analyze, the ROI is
not bigger in size, the hippocampal ROI lies directly over the actual
hippocampus in the MPRAGE). This suggests that SPM5 is reading the header
information of the files generated from Analyze 8.1 incorrectly. Can
anyone let me know how to read and change the header files in SPM5? Also,
is there a particular piece of information within the header file that I
can modify to correct for these problems?
Center for Mind and Brain
Neurocognitive Development Lab
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