[Insight-users] Re: [Insight-users Atlas based segmentation

[Luis Ibanez]

Hi Radhika,


The approach you suggest is reasonable.

You just need to make sure that when
your register the two T2 images, you
use the non-segmented one as the fixed
image.

In that way you will get the deformation
field that allows to resample the binary
mask of the already segmented image.
In other words, your atlas must be in
the "moving image" space.

Once you get the resampled binary mask you
could also use it to initialize any of the
multiple level set methods in ITK.

For example, the GeodesicActiveContours
level set.

It depends on how much your region is defined
by clear edges or by the homogeneity of the
internal pixels.



Regards,


    Luis



--------------------------------
Radhika Sivaramakrishna wrote:
..

  I had a question regarding using atlas based segmentation.
> 
> I already have a few T2-weighted images with the intracranial volume (ICV)
> labelled (binary images with ones in ICV region and zeros elsewhere). I want
> to use this to be able to segment the ICV in future T2-weighted images. I am
> sure they will benefit from an atlas segmentation, since the regions look
> very similar to each other.
> 
> I was thinking of first registering an image for which I have a
> corresponding mask available with an unknown image, and obtaining a
> deformation field using the demons algorithm. I will then deform the
> corresponding mask using the same field and use this as a starting mask for
> the hybrid segmentation process which uses a combination of fuzzy
> connectedness and voronoi segmentation. Can you tell me if this is the way
> to go or you can recommend a different approach?
> 
> Thanks
> Radhika
> 
> 
> 
>