I have acquired three dynamic PET scans (once before and twice after
treatment) from the same animals using microPET. Each PET scan is composed
of 36 frames. In addition, I have also acquired T1 MRI from each subject.
In order to investigate the effects of treatment on the binding potentials
of D2/D3 receptors, I tried the following procedures using SPM2; it seems to
1. Realigned all frames in each scan to the middle frame of the scan and
generate the meanPET (e.g., meanPET_scan1) and realigned PET frames.
2. Coregistered the meanPET_scan2 (or meanPET_scan3) to the meanPET_scan1 as
source=meanPET_scan2 (or meanPET_scan3)
others=realigned PET frames of the scan2 (or scan3)
3. Coregistered the MRI and ROI masks to the meanPET_scan1.
Basically, I coregistered everything to the meanPET-scan1.
Is the step 2 (e.g., use of coregistration in within modality registration
of the images from the same subject) correct?
Can I introduce any artifacts by using the coregistration in step2?
In other words, do I have to use 'Realignment' if I want to register
multiple PET scans acquired from the same subject as below.
1. Realign all frames in each scan to the middle frame of the scan and
generate the meanPET (meanPET_scan1, meanPET_scan2, and meanPET_scan3).
2. Realign all frames from all scans including scan1 to the meanPET_scan1
and generated realinged PET frames.
Or, should I run only one Realignment as below.
1. Realign all frame from all scans to the middle frame of the first scan.