dear list.
sorry about probably sending my request again, but i did get a message, that
my post has not been send to the list.
i am interested in reanalyzing a set of vbm data with the DARTEL approach.
the chapter of john ashburner has been very helpful to get through the
steps, but still a few questions are unanswered. former posts in the list
are not helpful because they were to technical for me. so maybe there is
help on a basic level?
1. 2 of my t1.nii images are not very good realigned in native space.
without being very familiar with the correct terms (pitch, roll,yaw) the
axial slices seem to be tilted about +10 degree from the sagital line (i
assume this to be yaw?). i guess it should be better to realign these images
before including into the process? i tried a bit with the display tool in
spm5, playing around with the yaw section but was not able to tilt the
images in the right direction. any suggestion about where (pitch, roll, yaw)
i should enter what for a tilt of 10 degree?
2. as far as i understood it right, the resulting smwrc1*-images are all
"warped" into the average shape and size and to this related already warped?
if i want them to be normalized into mni space i should follow the steps in
john's script 1.2 and 1.2.2. do i have to smooth them again or warp them or
anything else after these steps? i did not understand the posts in the list
about that topic.
3. after normalization into mni space, the resulting images look strange,
somewhat frayed on the cortical edges. they look much worse than the former
images. what happened?
thanks
markus
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