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<DIV><FONT face=Arial size=2>Hi together,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I just want to ask briefly, if somebody
has</FONT></DIV>
<DIV><FONT face=Arial size=2>tried the FEM - registration in 3D with Mutual
</FONT><FONT face=Arial size=2>Information metric.</FONT></DIV>
<DIV><FONT face=Arial size=2>I currently try to register a MR to a CT
volume</FONT></DIV>
<DIV><FONT face=Arial size=2>(thorax, significant missregistration due to lung
movement),</FONT></DIV>
<DIV><FONT face=Arial size=2>but the registration runs only for 2
iterations and calculates</FONT></DIV>
<DIV><FONT face=Arial size=2>a deformation field with very small
values.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>The parameters I used were like
follows:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>rho = E = 1000</FONT></DIV>
<DIV><FONT face=Arial size=2>gamma = 1.0</FONT></DIV>
<DIV><FONT face=Arial size=2>timestep = 10</FONT></DIV>
<DIV><FONT face=Arial size=2>alpha = 1.0</FONT></DIV>
<DIV><FONT face=Arial size=2>energy reduction factor = 1e-12</FONT></DIV>
<DIV><FONT face=Arial size=2>Width of metric region = 2</FONT></DIV>
<DIV><FONT face=Arial size=2>pix per element = 6</FONT></DIV>
<DIV><FONT face=Arial size=2>number of integration points = 4</FONT></DIV>
<DIV><FONT face=Arial size=2>Max Iterations = 80</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Program gives maxVec = 0.004,</FONT></DIV>
<DIV><FONT face=Arial size=2>displacement values mostly about
1e-6 !!!</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>It is a little bit strange, because although the
values for E and rho</FONT></DIV>
<DIV><FONT face=Arial size=2>are very small (with monomodality CT
datasets, I got it working </FONT></DIV>
<DIV><FONT face=Arial size=2>in a multi - resolution </FONT><FONT face=Arial
size=2>strategy with starting elasticity E = 500.000), </FONT></DIV>
<DIV><FONT face=Arial size=2>I'm little bit confused about this behavoir
now.</FONT></DIV>
<DIV><FONT face=Arial size=2>I also tried higher time steps, but this also did
not work.</FONT></DIV>
<DIV><FONT face=Arial size=2>The critical component may be the
metric.</FONT></DIV>
<DIV><FONT face=Arial size=2>So, what is the relationship between the metric and
the parameter settings?</FONT></DIV>
<DIV><FONT face=Arial size=2>Has somebody gained more experience with this
filter, perhaps on different datasets</FONT></DIV>
<DIV><FONT face=Arial size=2>and with different metrics and wants to share
his/her experiences with me???</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>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
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