Ok, I see. That makes much more sense now. The first way definitely
sounds like the way to go. Thanks so much!
Kristen
-----Original Message-----
From: FSL - FMRIB's Software Library [mailto:[log in to unmask]] On
Behalf Of Saad Jbabdi
Sent: Thursday, January 15, 2009 9:21 AM
To: [log in to unmask]
Subject: Re: [FSL] Probtrackx - Two masks
Hi Kristen,
The difference is that in one case, both masks are used as seed and
waypoint in alternation, whilst in the second case there is only one
seed
and one waypoint. If you want to trace pathways connecting your two
masks,
the first option is often more sensitive.
Saad.
> Oops, I meant to further elaborate my question to make sure that I was
> choosing the right way of getting the data I want. I understand that
> choosing multiple masks and entering two masks there is the equivalent
to
> the old "two masks - symmetric", but if I only want to identify
pathways
> connecting my two masks, is that the better method to use or is
choosing
> single mask with a waypoint mask better? I guess I just don't see
what
> the difference is between the two methods. Thanks for your help! I
> really appreciate it!
>
> Kristen
>
>
> -----Original Message-----
> From: FSL - FMRIB's Software Library on behalf of Lindgren, Kristen,
Ann
> Sent: Wed 1/14/2009 6:53 PM
> To: [log in to unmask]
> Subject: Re: [FSL] Probtrackx - Two masks
>
> Thanks, Saad. Then how is the second way different (selecting one
seed
> mask and then one waypoint mask)? What kind of results would that
> yield? I figure it's best to clarify this now before I start running
a
> ton of datasets through. Thanks again!
>
>
>
> Kristen
>
>
>
> ________________________________
>
> From: FSL - FMRIB's Software Library [mailto:[log in to unmask]] On
> Behalf Of Saad Jbabdi
> Sent: Wednesday, January 14, 2009 6:49 PM
> To: [log in to unmask]
> Subject: Re: [FSL] Probtrackx - Two masks
>
>
>
> Hi Kristen,
>
>
>
> The old two-mask-symmetric mode is equivalent to the first option that
> you are describing, i.e. "multiple masks" with masks 1 and 2.
>
>
>
> Cheers,
>
> Saad.
>
>
>
> On 14 Jan 2009, at 19:23, Lindgren, Kristen, Ann wrote:
>
>
>
>
>
> Hello. Way back when in an older version of FSL, I had been using
"Two
> masks -symmetric" in probtrack to identify pathways common to the two
> masks (ie. only want paths that go through both masks). Now that I'm
> using probtrackx, I just want to make sure that I'm picking the right
> options. Do I just want to pick "multiple masks," enter the masks 1
and
> 2 or do I need to run "single mask," enter mask 1, and then enter mask
2
> under waypoints masks? Or is there something else I should be doing?
> Thanks!
>
>
>
> Kristen
>
>
>
> Saad Jbabdi
>
> Oxford University FMRIB Centre
>
>
>
> JR Hospital, Headington, OX3 9DU, UK
>
> +44 (0) 1865 222545 (fax 717)
>
> www.fmrib.ox.ac.uk/~saad
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
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