On Mon, 24 Dec 2018 15:40:24 -0500, Jeff Browndyke <[log in to unmask]> wrote:
>When applying forward deformations generated by CAT12 to SPECT (or other co-registered data types) are the resulting warped data modulated in a fashion similar to that achieved by CAT12 (i.e, Jacobian determinant)?
The deformation function in CAT12 allows to switch off the modulation for any other data than VBM.
>SPECT and ASL data from which I would like to obtain mean values from CAT12 generated ROIs. However, there are some areas of artifact in these data that I would like to exclude from processing, but I’m not certain how to implement this. There used to be a lesion masking function, but I don’t see it in the newest CAT12 version.
Have you tried the non-linear co-registration in CAT12 for your data? This co-registration tries to minimize the EPI-distortions in fMRI or DTI data, but probably also works for ASL data if you have distorted areas.
If the T1 image has no lesions than no lesion processing is necessary, because the estimated deformation are unaffected of any lesions and can be applied to your ASL or SPECT data. However, for estimating the mean values inside a ROI you have to exclude the lesion areas to ensure that the mean values are unaffected. Probably it works if you set the lesions to NaN, but I haven't tried that. The safest would be to exclude any ROI that is containing a lesion.
>Any tips, clarifications or suggestions would be most appreciated.
>Duke University Medical Center