[Insight-users] Registering US -> CT

[N.E. Mackenzie Mackay]

Hi,

	I have tried for the last while to get a single ultrasound image to 
register to a CT volume.  Specifically try to get the bone of an 
ultrasound image and bone of the CT to register together.  Up to now I 
am having quite some trouble.

I have been able to segment the bone from CT and give an estimate on 
where the bone is in the ultrasound.  I am now trying to register those 
two images.

This is what I am using:

MattesMutualInformationImageToImageMetric - decided to use this because 
the registration was of two different modalities.  Couldn't use feature 
registration becuase to hard to segment ultrasound correctly
	- using 50 bins and %20-%100 of samples still doesn't give adequate 
results.

linearInterpolateImageFunction

RegularSetGradientDecentOptimizer

Euler3DTransform

Both images ( 3D CT and US ) are normalized before the registration.

I have used a maximum step ranging from 0.5-6.  And a min step of 0.005 
- 1.

I have a good initial guess ( maximum 2cm away from correct with about 
0- 30degrees of rotation)

I tested out the registration method in 2D and have had success.  When 
I use the exact same variables applied in 3D the registration is poor.

Does anyone have any suggestions?  I would be happy to provide a couple 
of images or actual code to show you what I am dealing with.

Neilson