Thanks for the catch.
I sincerely hope nobody is using this plugin for surgery planning (yet) 
Now that I think about it, I never compared my renders to any industry-standard MHD/DICOM visualizers, could be that this happens for all data or it could be just for some specific MHD/DICOM images that have some tags that I don’t know about.
Does it happen to all data you tried? Does it happen with .mhd or .dcm?
My implementation of the DICOM loader is very experimental now.
Could you share the data? There could be a thousand reason why this happens and I need more details.
EDIT : Seems like you’re right and everything is flipped. I find it hilarious that nobody (me included) noticed until now…