<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<META content="MSHTML 6.00.2900.2963" name=GENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=#ffffff>
<DIV><FONT face=Arial size=2>Hi insight users,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I currently tried to use the
ITKCurvatureRegistrationFilter</FONT></DIV>
<DIV><FONT face=Arial size=2>with different registration
functions (itkMIRegistrationFunction, </FONT></DIV>
<DIV><FONT face=Arial size=2>itkSymmetricForcesDemonsRegistrationFunction,
MeanSquaresRegistrationFunction)</FONT></DIV>
<DIV><FONT face=Arial size=2>to register two head/neck CT
images.</FONT></DIV>
<DIV><FONT face=Arial size=2>I used a constraint weight of 1000 and a time step
of 100 for 10 iterations (just to see</FONT></DIV>
<DIV><FONT face=Arial size=2>in which direction the deformationfield
evolves).</FONT></DIV>
<DIV><FONT face=Arial size=2>The 2 CT images also show a slight rigid
mis-registration, which curvatureRegistration</FONT></DIV>
<DIV><FONT face=Arial size=2>is said to take into account.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>As compared to using
itkSymmetricForcesDemonsRegistrationFunction</FONT></DIV>
<DIV><FONT face=Arial size=2>or itkMeanSquaresRegistrationFunction,
using itkMIRegistrationFunction computes a </FONT></DIV>
<DIV><FONT face=Arial size=2>displacement field </FONT><FONT face=Arial
size=2>which is opposed to the deformation field, using the other
two metrics</FONT></DIV>
<DIV><FONT face=Arial size=2>(which apparently calculate a displacement
field, that evolves in the right direction).</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Following the sourcecode documentation of
ITKCurvatureRegistrationFilter (ITK v2.4.0, I also</FONT></DIV>
<DIV><FONT face=Arial size=2>noticed </FONT><FONT face=Arial size=2>that the
source comments do not appear in the cvs doxygen documentation!!!),
</FONT></DIV>
<DIV><FONT face=Arial size=2>it should work with </FONT><FONT face=Arial
size=2>any RegistrationFunction.</FONT></DIV>
<DIV><FONT face=Arial size=2>I also tried to set DoInverse(true) on the
itkMIRegistrationFunction, but still get the same results.</FONT></DIV>
<DIV><FONT face=Arial size=2>I guess it has something to do with the negative
sign of the MI Metric but could still not figure it out.</FONT></DIV>
<DIV><FONT face=Arial size=2>Has somebody had the same
effect or can comment on that???</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Regards,</FONT></DIV>
<DIV><FONT face=Arial size=2>Markus</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV></BODY></HTML>