Test deformation with ITK v4.0rc02.

The imaging registration is an important step in the medical imaging. In there, the deformable registration is a difficult subject. In this article, I show some results of deformable registration implemented in the Itk 4.0.


Test deformation with ITK v4.0rc02.

BSpline result
Time and memory took by this method

         Probe Tag    Starts    Stops             Time (s)
Affine Registration            1            1           112.283
Deformable Registration Coarse           1            1           49.8462
Deformable Registration Fine            1            1           67.5788
Rigid Initialization            1            1           13.0866
Rigid Registration            1            1           32.1134
         Probe Tag    Starts    Stops           Memory (kB)
Affine Registration           1            1              4872
Deformable Registration Coarse            1            1             30020
Deformable Registration Fine           1            1              6408
Rigid Initialization            1            1                 0
Rigid Registration           1            1              3692

These are the images of difference between the fixed image and before (after) deformation of the moving image. The region of difference with the before deformation is large because of the mismatch of position of two samples.

The region of difference with the after deformation is small.

Image 5	Image 6
Image 17	Image 18

In the result of image 5 and 6, the white round center region is not matched between the fixed and moving image. So, this region is divided in two. In the image 17 and 18, the difference image show the match in this region. So, there is only a small thin circle in the difference between the moving and fixed images.


Result of Demons method
This is the difference image between the fixed and deformation of the moving image using the Demons method.

Demons Image 5	Demons Image 6
Demons Image17	Demons Image 18

By the above images, we see the result of Demons is better than BSpline. But there is some region error in the lasting images.


Result of FEM.
Now, after testing with the FEM Method, the result obtained is not good. It seems the simple translation is not done.


Resume:
Demons gives us a better result but the time taken is so long (about one hour).
With the BSpline method, the result and the time taken are acceptable. The execute time is about five minutes.
There is some FEM error, the translation is not well done.