> We are working on VBM and have a slight problem with crosshair positioning.
> Apparently there are two different ways of realigning the crosshair with
> ac-pc-orientation:
> The first is using the "Reorient Images .." function and the second is
> changing the position through "HDR edit". Browsing through the mail list I
> couldn't figure out if there is a difference and which method is the better
> one.
>
> Does anyone know which is the better to use?
If your images have any .mat files, then using the "HDR edit" option won't
work. The positioning of the images is derived from the contents of any
.mat files if they exist. Otherwise, the ORIGIN and VOX fields are read from
the .hdr files.
Personally, I would use the "Reorient images..." option from "Display" as it
is interractive, it works whether or not images have .mat files (so can be used
after realignment or coregistration - providing that the same reorientation
is applied to all images), it allows the angle of the images to be changed and
the accuracy of the translations can be by less than a voxel. The disadvantage
is that it relies on images having additional .mat files.
Best regards,
-John
--
Dr John Ashburner.
Functional Imaging Lab., 12 Queen Square, London WC1N 3BG, UK.
tel: +44 (0)20 78337491 or +44 (0)20 78373611 x4381
fax: +44 (0)20 78131420 http://www.fil.ion.ucl.ac.uk/~john
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