Dear all,
I would liket ask help regarding coregistration of a T1 MRI to the dynamic
PET images.
I have been using SPM2 to transfer the volume of interest (VOI) drawn on T1
MRI image to 34 frames of dynamic PET images using the following steps.
1. Regalign 33 frames to 17th frame using 'Realign' and genereate the mean
PET image.
2. Coregister T1 MRI to the mean PET image and at the same time coregister
the VOI mask images to the mean PET image as other images.
The coregistration seems to be OK, but when I closely take a look at the
accuracy of coregistration, it is not as accurate as I would like to see,
especially in the striatum around the ventricle.
For example, the center of a circle drawn on the caudate of the coregistered
MRI DOES NOT match the hottest spot of the caudate of the coregistered mean
PET image. In generall, the activity (image) of the caudate, in the PET
image, seems to be a little bit off from the ventricle.
I suspect this might be true becasue of partial volume effects.
Due to low activity of ventricle, the activity near the ventricle will be
relatively lower than other parts of the caudate.
I wonder if anybody has a similar problem like this.
Any suggestions?
Thank you,
Buyean Lee.
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