[vtkusers] Extract the Heart from CT data sets and Rendering the Volume

[wassim_belhadj at topnet.tn]

Hi 
I 'a m using VTK 
I am using CT data sets that contain Bones and  the Heart.  
I would like to extract only the heart from The CT data sets and Rendering
the Volume using VTK.
I dont kow how to extract the Heart (removing the bony part) .
Should I make a segmentation?
Can you help me in providing  some examples of code (I am novice with the
use of VTK).
I tried to extract the heart  by using the transfer function  but I  have
always some bone !
I hope get help ...
Thanks in advance