[Insight-users] calculators?

[Luis Ibanez]

Hi Yasser,

There is no real physical meaning for
the "Mass" in the Moments Calculator.

One way of interpreting this concept
is to think that the intensity levels
in the pixels of your image are proportional
to the content of a particular substance
on the patient.

The total mass is simply the sum of all
the intensities in the image, and therefore
it could be seen as proportional to the amount
of that substance.  Unfortunately most image
modalities are not that specific. (unless
you are using markers in molecular imaging
where there is a lot more of specificity).

In practice you should only use the moments
as rough indicators of the location and
orientation of the brightness in your image.


If what you want is to compute volumes and
to estimate masses of anatomical structures
you must start by performing segmentation
on those specific structures.



    Regards,



      Luis



---------------------
yasser salman wrote:

> hi all..,
> i'm using the  calculators to calculate the total mass
> of my 3D region, i need to know the physical meaning
> to calculates the first moments . i read the comments
> in deoxgen and also in .h files but still missing the
> meaning, also can i found anthor volumetric
> measurements for 3d region (brain tumors in my case)
> in itk..,?
> 
> calculator->SetImage( connectedThreshold->GetOutput()
> );
>  calculator->Compute();
> double area = calculator->GetTotalMass()/255;
> thanx .,
> yasser..,
> 
> __________________________________