volume calculation

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marine
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volume calculation

Post by marine »

Hello !
Is there a command to calculate the volume of a ROI or the volume of a mesh please ?
Best regards,
Marine
Dominique Geffroy
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Re: volume calculation

Post by Dominique Geffroy »

Hi marine,

The command AimsVoiStat seems to do that. You give as parameters a volume and a roi graph and it computes statistics about the ROIs, including volume.

Example : AimsVoiStat -i image.ima -v graph.arg -o stats.txt

Dominique
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riviere
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Re: volume calculation

Post by riviere »

Hi,
For a mesh, the volume inside a closed mesh can be calculated by AimsMeshArea.
Denis
marine
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Re: volume calculation

Post by marine »

Ok for the calculation of a mesh volume.
For a ROI volume, how can I create the corresponding .arg file of a binary volume (2D . nii file) please ?
Marine
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riviere
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Re: volume calculation

Post by riviere »

For a binary volume you can also use AimsMassCenter, which computes the volume, mass and mass center in a volume.
Otherwise converting a binary volume to a ROI graph is done using AimsGraphConvert:

Code: Select all

AimsGraphConvert binvolume.nii outroi.arg
Denis
marine
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Re: volume calculation

Post by marine »

Well !
Thank you very much !
Marine
houenou
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Re: volume calculation

Post by houenou »

Hi,
Thanks for the AimsVoiStat command explanation.
Its output is like this:
RoiName| StTime| DuTime| Volume| Mean| StdDev| Min| Max

I tried this on a single arg drawn on a T1 image; therefore I don't understand how it outputs a Mean, StdDev, Min and Max ? What are StTime and DuTime for ???
thanks,
Josselin
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riviere
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Re: volume calculation

Post by riviere »

Hi Josselin,
AimsVoiStats was primarily designed for 4D activation maps. On a single 3D image, the time stats should be quite meaningless. The mean and fixed-time stdDev are calculated on the grey levels on the regions, so they are meaningfull.
Denis
houenou
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Re: volume calculation

Post by houenou »

Hi,
Thanks. Is the volume resuls given in mm3 or in voxels ?
Josselin
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riviere
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Re: volume calculation

Post by riviere »

It's in mm3.
Denis
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