Hi!
Our experience with segmenting Simens 3D--MPRAGE images has indicated that
betpremask helps a lot with the problems in segmenting the basal parts of
the brain. It seems that setting the center for the sphere is crucial as
well (-s option in bet).
-Antti
--
Antti Korvenoja
Biomedicum Helsinki, Radiology
P.O. Box 700, 00029 HUS
Finland
tel: +358-9-47171786 : mobile: +358-40-7498469
Quoting "Lee, Sang" <[log in to unmask]>:
> Dear, FSL users...
>
> I'm quite a newbie at FSL.
> I wanted to run BET on some of our 3D T1 images.
>
> In some images, the segmentation is wonderful, however in some cases,
> some
> of non-brain matter below the brain and eye-socket are not removed.
> I tried to raise the Fractional intensity threshold, but that removes
> brain
> matters as well.
> Also, CSF comes out to be larger than grey or white matter when I
> perform
> FAST on those ones that have problem.
>
> Is there something that i can do to improve the segmentation?
>
> Image sets that are having these problems have following scan
> parameters:
> Slice thickness = 1.5
> FOV =24
> TR = 9
> TE = 1.8
> FA = 10
>
> Image sets that are great with BET and FAST have following scan
> paramters:
> slice thickness = 1.2
> FOV = 25
> TR = 20
> TE = 6
> FA = 20
>
> Both are 3D-SPGR images.
> Can any of you tell me what factors might affect BET and FAST procedures
> and
> the solution for those problems?
>
> Thank you very much.
>
> Aaron****************************EMAIL
> DISCLAIMER****************************This e-mail and any files
> transmitted
> with it may be confidential and are intended solely for the use of the
> individual or entity to whom they are addressed. If you are not the
> intended recipient or the individual responsible for delivering the
> e-mail
> to the intended recipient, any disclosure, copying, distribution or any
> action taken or omitted to be taken in reliance on it, is strictly
> prohibited. If you have received this e-mail in error, please delete it
> and
> notify the sender or contact Health Information Management 312.413.4947.
>
|