The "radiological" v "neurological" nomenclature only applies to the
display of axial or coronal images. When dealing with 3D stuff, you
should really be thinking about left-handed or right-handed coordinate
systems. One of these is the mirror image of the other. See
http://en.wikipedia.org/wiki/File:Cartesian_coordinate_system_handedness.svg
Talairach and MNI coordinates (as well as the actual mm locations in
NIfTI files) are right-handed.
When rendering surfaces, if the software interprets the handedness
correctly, the rendering should appear OK (and not as a mirror image).
% In MATLAB, you can plot right handed coordinates using:
subplot(2,2,1); plot3(0,0,0); xlabel('X'); ylabel('Y'); zlabel('Z')
axis equal; rotate3d on
set(gca,'Xdir','normal','Ydir','normal','Zdir','normal')
title('Right-Handed')
% And left-handed coordinates with:
subplot(2,2,2); plot3(0,0,0); xlabel('X'); ylabel('Y'); zlabel('Z')
axis equal; rotate3d on
set(gca,'Xdir','normal','Ydir','reverse','Zdir','normal')
title('Left-Handed')
By default, MATLAB seems to use a right-handed system.
Best regards,
-John
On 4 April 2012 17:21, Kie Woo Nam <[log in to unmask]> wrote:
> Dear experts,
>
> My apologies for posting something not directly relevant to SPM, but could someone please advise me how to interpret the left-right orientation of cortical surface images? I would appreciate it if you would check attached the pictures, each showing a different interpretation, and specify which one is correct.
>
> These images have been produced using CIVET pipeline for cortical surface extraction. The CIVET uses MINC images, and all MINC tools display images in neurological (i.e. image left = true left) convention, but I assume this "radiological (i.e. image left = true right) vs neurological" issue does not apply to the cortical surface images (especially judging from attached the image, "Chaos.jpg"). Am I correct to say this?
>
> Many thanks,
>
> Kie Woo
|