Hi John,
>> My feeling is that, especially with new segment, this is a good idea as
>> sometimes the affine registration does not like heavily "disoriented"
>> brains (you know what I mean :)
>
> Don't you mean the older segment? The new segment of SPM8 should be
> much more robust to this sort of thing.
Well, I may have had some rather abnormal brains, working with early
lesions, but when starting to play with it some time ago, I have
encountered problems achieving a good affine registration using the
newer functions such that I needed to revert to the older versions, as in
lastwarn('');
try,
Affine = spm_maff8(...);
error(lastwarn);
catch,
clc
fprintf([' Unable to find an affine matrix using mutual',...
' information, reverting to least squares...' '\n'])
[Affine, scal] = spm_affreg(...);
end;
I never systematically explored this, though, and cannot say whether it
was an issue of too much motion artefacts or not enough brain tissue
(both not too uncommon), or other factors I changed :)
Best,
Marko
--
=====================================================================
Marko Wilke (Dr.med./M.D.)
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Universitäts-Kinderklinik University Children's Hospital
Abt. III (Neuropädiatrie) Dept. III (Pediatric neurology)
Hoppe-Seyler-Str. 1, D - 72076 Tübingen
Tel.: (+49) 07071 29-83416 Fax: (+49) 07071 29-5473
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