[Rtk-users] CBCT reconstruction using rtkfdk

[Simon Rit]

Hi,
If your first projection and your last projections are at the same
position, you probably want to use
rtksimulatedgeometry --output="geometry.xml" --nproj=721 --arc=360.5
--sdd=553.74 --sid=230.66

You indicate --newspacing 0.5 but your metadata says 0.05? The Hamamatsu
Photonics C7942CA-22 seems to have 2400x2400 pixels so you probably want to
use (if your detector is well aligned)
rtkprojections --path "D:\CT projection\walnut" --output "projections.mha"
--regexp .tif --newspacing 0.05 --neworigin -1199.75,-1199.75,0
(the last coordinate of origin is ignored).
Simon

On Mon, Jul 3, 2023 at 8:10 AM Kim HyunJoon <anslasax18 at gmail.com> wrote:

> Hello
>
> I am newbie at RTK and tried to reconstruct 3D cbct dataset of a walnut(
> https://zenodo.org/record/6986012) using rtkfdk.exe but
> result was not good.
>
> The script I used is:
>
> rtksimulatedgeometry --output="geometry.xml" --nproj=721 --arc=360.0
> --sdd=553.74 --sid=230.66
>
> rtkprojections --path "D:\CT projection\walnut" --output "projections.mha"
> --regexp .tif --newspacing 0.5
>
> rtkfdk -p . -r projections.mha -o fdk.mha -g geometry.xml --spacing
> 0.05,0.05,0.05 --dimension=128,128,128 --neworigin -64.5,-64.5,0
>
>
> Metadata describing the measurement geometry and settings for walnut
> projection dataset:
>
> [GENERAL]
> ProjectName=20201111_walnut_
> Scanner=University of Helsinki Industrial Mathematics Computed Tomography
> Laboratory
> Measurers=Alexander Meaney
> Date=20201111
> DateFormat=YYYYMMDD
>
> [GEOMETRY]
> GeometryType=Cone
> DistanceSourceDetector=553.74
> DistanceSourceOrigin=210.66
> DistanceUnit=mm
>
> [ACQUISITION]
> NumberImages=721
> AngleFirst=0
> AngleInterval=0.5
> AngleLast=360
>
> [DETECTOR]
> Detector=Hamamatsu Photonics C7942CA-22
> DetectorType=EID
> Binning=1x1
> PixelSize=0.050
> PixelSizeUnit=mm
> ExposureTime=1000
> ExposureTimeUnit=ms
>
> [XRAY]
> Tube=Oxford Instruments XTF5011
> Target=Mo
> Voltage=40
> VoltageUnit=kV
> Current=1.0
> CurrentUnit=mA
> XRayFilter=None
> XRayFilterThickness=N/A
> XRayFilterThicknessUnit=mm
>
>
> The output data (fdk.mha) doesn't look very walnut when I open it in
> volview (https://volview.kitware.app/).
> Some of the parameters seem to be wrong, but I'm not sure where exactly
> the problem is.
>
> I would appreciate it if you could tell me how to solve the problem.
> Thank you in advance.
>
> Ansalsax
>
>
>
>
>
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