Hi Everybody,
In a neonatal study at our hospital there has been interest in using TBSS on
the diffusion data (15 dir overplus, b= 750, voxel size=1.4/1.4/2mm). We have
done some preliminary attemps, but been running into registration problems.
All input data is in the same orientation (double checked), but all outputs from
tbss_3_postreg (e.g. mean_FA ) gets a heavy rotation around the R-L axis
and a chopping of the frontal lobe (due to the rotation). From just looking at
the mean_FA the bigger tracts seems to have registered fairly, but it is hard
to tell due to the strange view it gets presented in.
We have used the -n flag when doing the registration, since we have not
found/known about any good neonatal target space. The registration has also
been tried without only the controls (suggesting that the rotation would be
due to patient morphology), but with the same result. The registration has
been running nicely on adults, when using the same parameters.
Has anyone else experienced similar problems?
Any views on if there is something that can be done to improve the results
would be very much appreciated, or what this is due to (e.g. to high noise
level in the data, to big morphologic differences, etc. )
Regards,
Mathias Engström, Karolinska University Hospital
|