[MINC-users] 6-parameter fitting with minctracc

[Jason Lerch]

In my limited experience you're much better off processing each of the scans independently and then either averaging the thickness maps at the end or, even better, using mixed effects models and all your data for the analysis.

Alternately, if you really want to go the higher SNR route, I have a nonlinear-mritoself perl script that might help.

Jason

On 2010-02-20, at 12:36 PM, EJ Nikelski wrote:

> Hi all,
> 
>  I need some validation and/or suggestions (or both?).  I have
> subject scans (T1) for which each subject was scanned multiple times
> (same scanner), at difference points in time.  For each subject, some
> of the scans were acquired within the same scanning sessions, some
> were acquired within a 6-month window.
> 
>     I would like to combine the scans to give me the best SNR for
> Civet processing.  I've tried specifying one of the scans as the
> "target" and then using "mritoself" to align all others to it; all
> aligned scans and the "target" would then be mincaverage'd.  The
> results are OK, but not splendid, as Civet spits up during tissue
> classification on one of the averaged volumes, although the
> non-averaged scans go through without error.  I'm using defaults for
> the mritoself call, plus "-nocrop".
> 
>    Does anyone have any experience in this. Ideas? Suggestions?
> Magical incantations?
> 
> Thanks,
> 
> -Jim
> 
> 
> -- 
> =================================
> Jim Nikelski, Ph.D.
> Postdoctoral Research Fellow
> Bloomfield Centre for Research in Aging
> Lady Davis Institute for Medical Research
> Sir Mortimer B. Davis - Jewish General Hospital
> McGill University
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