[Insight-users] Re: registration: CT to PET

[Luis Ibanez]

Hi Soumend

Your CT DICOM image 1188316 was ok,
but the Image.-110_0.dcm was not
readable by ITK readers, nor by
MRIConvert.

Could you please resend it in another format ?

The scheme that you are using doesn't seem
to be reasonable. Note that you can do this
registration in 3D, no need to do it slice by
slice. It is almost imposible that you will be
able to follow the 3D trajectories of the actual
images in 3D just by manually  tracking the
correspondences between slices in one image and
slices in the other image.

To put it short:   Please do this in 3D.

You will find multiple examples of Multimodality
registration in the SoftwareGuide

   http://www.itk.org/ItkSoftwareGuide.pdf

and the associated source code is available on
the Insight/Examples/Registration directory.

---

In order to verify if the final transform parameters
are appropriate, you simply use those parameters for
setting up a transform and use it in the ResampleImage
Filter in order to reformat the Moving image into the
space of the FixedImage.

Almost all the examples in Insight/Examples/Registration
do this resampling at the end.

Once you have resampled the moving image, you use any
visualization tool in order to superimpose the fixed
image and the resampled moving image.  You could do
this directly by using VolView. The free version of
VolView can be downloaded from:

   http://www.kitware.com/products/volview.html

Or, if you prefer to write your own code, you could
use VTK classes such as the vtkImageBlend filter and
the vtkImageViewer.


    Regards,


       Luis


-----------------------------------
soumend at magnum.barc.ernet.in wrote:
> hi!!!!
> 
> I have wriiten a program to register one CT image(512X512)with one PET Image 
> (128X128). But the problem is I donno whether the transform parameters I am 
> getting as output after registration are right or not. So I am sending the two 
> image files as attachments plz let me know the transform parameters which 
> result correct registration. I am using Mattes MI metric for registration.
> 
> Anothe thing ....I am following the scheme stated below...
> 
> Actually I have 116 CT images and 163 Pet images. I am taking fixed slice name 
> from the user and finding the moving slice from the other directory.To do that 
> I am using the relative position of fixed slice from the furthest slice in its 
> series as guide. The moving slice which matches best with fixed slice in its 
> relative position wrt furthest slice in its series gets seleceted for 
> registration.
> eg. 
> fixed slice 1188316 (CT iamge, Slice Location=544, furthest slice in 
> series=654, relative posn=110)
> moving slice gets selected Image.110_0.dcm (PET image,slice location=-
> 110.5,furthest slice in series=0, relative posn=110.5)
> 
> Is this scheme reasonable? It works fine for my present data. But I want to 
> know what are the drawbacks of this scheme.
> 
> Ur Reply is eagerly awaited.           
> Thnx.
> 
> Soumen
> 
> 
> -------------------------------------------------