[Insight-users] Multi Modality Multi Resolution Doubt

Luis Ibanez luis.ibanez at kitware.com
Sat, 28 Feb 2004 10:55:23 -0500


Hi Abdul,

A reasonable registration proces will correct for
rotations of about 20 to 30 degrees.  Expecting
it to correct for image orientation (axial, coronal
saggital) is unrealistic and actually dangerous.

Registration is an optimization problem that is solved
with a cost function with multiple extrema. There is
no magic here, if you don't initialize the registration
close to the optimal region, you can end up anywhere,...
and don't have to much right to complain.


There are filters in ITK for correcting Flipping and
orienting images:

http://www.itk.org/Insight/Doxygen/html/classitk_1_1OrientImageFilter.html
http://www.itk.org/Insight/Doxygen/html/classitk_1_1FlipImageFilter.html
http://www.itk.org/Insight/Doxygen/html/classitk_1_1ReflectImageFilter.html

This is something that has to be done very carfully since
you could easily switch left-right on the patient image
and lead a surgeon to operate on the wrong side.


So, to answer your questions explicitly:

1) Yes, you must set the orientation to be the same
2) No,  ITK will not do that for you.
3) Yes, you need to supply parameters.



Regards,


    Luis


-----------------
CSPL wrote:

> Hi,
>  
>  I need to do some registration of SPECT[brain] with MRI[segmented 
> brain]. So i have choosen Multi Modality Multi Resolution Registration 
> and stuck with some problems. I am not getting the final results upto 
> the mark. Later i found that my MRI is in Coronal View and the SPECT is 
> in Transverse View. I want you to clarify in this point that
>  
> 1. Do we need to set the orientation of both the volumes same? or
> 2. Does ITK will itself look for this and REGISTER? or
> 3. Do we need to supply any parameters to get REGISTRATION even in this 
> situation?
>  
>  Please reply.
>  
> Thanks in Advance
> S. Abdul Rahim