[MINC-users] nu_correct & masking

[Andrew Janke]

Hi Richard,

I had hoped that John Sled would bite on this one, but it appears not
so here's my thoughts...

My feeling is that (2) is better.  The more data you give N3 to smooth
over the better it is going to perform. As far as I am aware, N3 does
not optimise over peaks per-se but rather the histogram in general. 
Thus as you way, the more "information" in the image the better.

Myself I tend to run nu_correct without a mask altogether beyond any
masking it does internally.

Andrew


On 12/07/05, Richard Boyes <rboyes@dementia.ion.ucl.ac.uk> wrote:
> Hello everybody
> 
> Regarding use of a mask with nu_correct, I have available
> to me two types:
> 
> 1. A brain mask that excludes CSF completely - ie WM, GM
>     only
> 
> 2. A 'filled' brain mask - ie includes the CSF in the sulcal
>     and ventricular spaces.
> 
> My question is, which mask is more effective? Intuitively
> I thought that the CSF mask would be better, as it gives 3
> classes in the histogram, which gives N3 3 histogram peaks
> to optimize over.
> 
> Thanks in advance
> Richard
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> 


-- 
Andrew Janke      (a.janke@gmail.com || www.cmr.uq.edu.au/~rotor)
Canada->Montreal                                   Cell: +1 (514) 924 2012