[vtkusers] Hounsfield Units : strange result (Volume rendering)

[wassim_belhadj at topnet.tn]

Hi,

I'am using VTK/VTKEdge and QT4 for volume rendering.

I 'am using a CT Datasets of a young person ( 35  years old)

I'm trying to define values of pixel that define lungs.

I assigned opacity to each pixel by checking its intensity value  with
Hounsfield Units values. 

Bone         +400 -----------> +1000

Soft tissue  +40 -----------> +80

Fat          -80 -----------> -100

Lung         -400 -----------> -600


I got a strange result !!  The volume obtained contains the lungs and skin 

 
According Hounsfield Units, the pixel values that form the skin and lungs
are not in the same interval.

I varied the opacity values to eliminate the skin that surrounds the lungs
but I have not succeeded.

Attached a screenshot that illustrates the problem.

Can someone help me ?

Best Regards,
BEHADJ wassim
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