[Rtk-users] R: Trying to reconstruct with a 180 degrees circular projection geometry

[gabriele.belotti.bergamo at gmail.com]

Hi Clément,

It seems likely that your geometry is not 180+fan-angle complete and therefore cannot lead to a proper reconstruction. From your attached geometry, you sweep from 0 to 178° (180-increment). 

My suggestion would be to try some intermediate angles, so to recreate a complete ShortScan. I suggest you to try at least a 200/220 ° arc to check on your simulation pipeline.

I hope this is helpful,
Gabriele

 

Da: Rtk-users <rtk-users-bounces at public.kitware.com> Per conto di Clément Mirabel
Inviato: venerdì 11 dicembre 2020 09:11
A: rtk-users at public.kitware.com
Oggetto: [Rtk-users] Trying to reconstruct with a 180 degrees circular projection geometry

 

Hi,

 

I have been trying to set the geometry in ThreeDCircularProjectionGeometry with values between 0 and 180 degrees, to reproduce the motion of some acquisition systems, but reconstruction is far from the expected result when the gantry angle does not reach max value of (360-increment). (Attached is the geometry file generated)

My workflow is the following :

*	Apply JosephForwardProjectionImageFilter on a 3D Volume
*	Try to reconstruct using FDKConeBeamReconstructionFilter

Although, the result from JosephForwardProjectionImageFilter describes a 180 degrees rotation, the output of the reconstruction seems to display rays from opposite direction but not from rotated directions

 

Here is a view of what is supposed to be an axial slice:



 

Thanks for your help!

 

Clément

 

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