Hi Elijah,
>differences in both techniques
which both techniques?
Note that SIENAr is not as sensitive in the area of the sulci as it is for
the ventricular borders because the brain edge is reduced to mainly the
outer border (cf. the standard space edge mask). SIENA does not suffer
from this limitation as here the sulci are adequately represented.
If you primarly expect sulcal widening you may be able to find it in the
individual flow images but the voxelwise multi-subject extension
(siena_flow2std / randomise) may miss it.
Cheers,
Andreas
Am 14.03.14 16:33 schrieb "Elijah Mak" unter <[log in to unmask]>:
>Hi Mark,
>
>I plan to use SIENA voxelwise to localize the brain regions exhibiting
>accelerated rate of atrophy between baseline and follow-up.
>
> What would be some of the biggest conceptual differences in both
>techniques? With SIENAr, we can examine regional atrophy rates without
>the need of intensity-based segmentation. Also, because SIENAr directly
>measures the shifts in brain edges, it does not suffer from ambiguous
>interpretation (is volume change due to real tissue loss or systematic
>alignment errors?)
>
>Looking forward to your expert opinion on this!
>
>Many thanks.
>
>Best Regards,
>Elijah
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