RTK/Scripts/FDK

3D

This script uses the file SheppLogan.txt as input.

 # Create a simulated geometry
 rtksimulatedgeometry -n 180 -o geometry.xml
 # You may add "--arc 200" to make the scan short or "--proj_iso_x 200" to offset the detector

 # Create projections of the phantom file
 rtkprojectgeometricphantom -g geometry.xml -o projections.mha --spacing 2 --dimension 256 --phantomfile SheppLogan.txt

 # Reconstruct
 rtkfdk -p . -r projections.mha -o fdk.mha -g geometry.xml --spacing 2 --dimension 256

 # Create a reference volume for comparison
 rtkdrawgeometricphantom --spacing 2 --dimension 256 --phantomfile SheppLogan.txt -o ref.mha

2D

The same reconstruction can be performed using the original 2D Shepp-Logan phantom. RTK can perform 2D reconstructions through images wide of 1 pixel in the y direction. The following script performs the same reconstruction as above in a 2D environment and uses the 2D Shepp-Logan phantom as input.

# Create a simulated geometry
rtksimulatedgeometry -n 180 -o geometry.xml

# Create projections of the phantom file
# Note the sinogram being 3 pixels wide in the y direction to allow back-projection interpolation in a 2D image
rtkprojectgeometricphantom -g geometry.xml -o projections.mha --spacing 2 --dimension=512,3,512 --phantomfile SheppLogan-2d.txt --phantomscale=256,1,256

# Reconstruct
rtkfdk -p . -r projections.mha -o fdk.mha -g geometry.xml --spacing 2 --dimension 256,1,256

# Create a reference volume for comparison
rtkdrawgeometricphantom --spacing 2 --dimension=256,1,256 --phantomfile SheppLogan-2d.txt -o ref.mha --phantomscale=256,1,256