Is there any problem with reorienting the template instead of the
My images are all "RPI Left-handed" and face downwards and to the
The original PET template faces upwards and t the left.
Using the "Top-to-Bottom" sorting in Pmod I receive the attached file
which is "RPI Left-handed" and faces downwards and to the right (I have
no idea why this file is almost exactly twice as large as the original
one - 1805610 By instead of 902981 By).
This way I could map my images to the template with only the template
changed in orientation.
I would like to assure myself: Is there a problem with that?
On 17.02.2012 21:40, John Ashburner wrote:
> LAI does indeed mean left, anterior, inferior. This encodes the
> location of the first voxel in the file, as well as the ordering of
> the directions. This order will depend on the file format converter
> you used, and it may be perfectly correct.
> How are you displaying the images? If you use the Display button of
> SPM, the PET.nii template should face upwards and to the left the
> as the various MRI templates. After the appropriate reorientation,
> your own image should be facing similarly. The thing to be careful
> though is whether left and right are correct. This is not something
> that I'd be able to tell you with any confidence.
> Best regards,
> On 17 February 2012 18:15, David Andel <[log in to unmask]> wrote:
>> Thanks a lot Bas, Donals, and John for your helpful answers!
>> Now I am reorienting my old images to fit the PET.nii template from
>> My original Analyze 7.5 images are "RPI Left-handed" and so is the
>> However, my images look up (transverse) and to the right (sagittal),
>> the PET.nii template looks down and to the left.
>> After reorienting my images using a yaw of pi (or -pi; or a pitch
>> and roll
>> of pi (or -pi) each) I receive the same orientation, but now my
>> images are
>> said by spm_orientations to be "LAI Left-handed".
>> I assume RPI means right, posterior, inferior, and LAI means left,
>> I guess this is a problem, isn't it?
>> Is there a way to reorient my images correctly in SPM or do I have
>> to use
>> third-party software (I have used Pmod in the past).
>> Just tested with Pmod where I reorder the slices "top to bottom" and
>> way the images fit and still are "RPI Left-handed".
>> I mean, yes, I have a solution, but is there a way to do the same in
>> SPM as
David Andel, MD-PhD candidate
Neuropsychopharmacology and Brain Imaging
Psychiatric University Hospital Zurich
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