Hi,
The bias field from FAST includes any factor that alters the
constancy of tissue intensity. Hence there are other terms apart
from the B1 bias field and these can have higher spatial frequencies.
However, there is also a smoothness constraint for the bias field which
can be increased if all you are interested in is the large scale (B1)
effects. Use the -l option with a large number (say 500) and you will
get higher smoothing.
All the best,
Mark
Adolf Pfefferbaum wrote:
> The bias field from FAST seems to have a higher spatial frequency than
> that from N3. N3 produces a field that looks primarily like B1. The one
> from FAST seems to have some anatomic detail. Can the bias field
> correction in FAST be turned of so I could compare FAST with N3 to FAST
> with its bias correction?
>
> Thanks,
>
> Dolf
>
> _______________________
> Adolf Pfefferbaum,MD
> Neuroscience Program
> SRI International
> 650-859-2927 phone
> 650-859-2743 FAX
|