Projection
-
Based Metal
-
Artifact
Reduction for Industrial 3D X
-
ray
Computed Tomography
Artem Amirkhanov
1,2
Michael Reiter
2
Johann Kastner
2
Christoph
Heinzl
2
M. Eduard Gröller
1
1
Institute of Computer Graphics
and Algorithms
Vienna University of Technology
2
Upper Austrian University of
Applied Sciences
Wels Campus, Austria
Artem Amirkhanov
1
Scanning Geometry
Artem Amirkhanov
2
Scanning Geometry
X
-
ray source
Specimen
Detector
Rotary plate
Projections
3D Volume
Reconstruction
Multi
-
Material Components (MMCs)
Artem Amirkhanov
3
Most industrial parts are MMCs
Materials:
Air
Plastic
Metal
Metal Artifacts
Artem Amirkhanov
4
Appear in MMCs
Metal artifacts
Dark
-
band artifacts
Streak
-
noise artifacts
Caused by
beam hardening
Bad for
Material
characterization
Measurements
Dark
-
band artifacts
Streak
-
noise artifacts
Our Contributions
Artem Amirkhanov
5
Adaptation of a projection
-
based
metal artifacts reduction
(MAR)
workflow for 3DXCT
Integrated visual analysis tool
MAR Workflow
Integrated VA Tool
Main Idea
Artem Amirkhanov
6
Artifacts source: projections
We remove metal from projections
We then reconstruct the 3D volume with
reduced artifacts
We insert the metal back into this volume
Streak
-
noise artifacts
Initial
Data
Initial Reconstruction
3D Volume
Metal
3D Volume
Without Metal
Projections
Metal Interpolated
Projection
MAR Volume
3D Volume
Output
Reconstruction
Material Separation
Forward Projection
Interpolation
Fusion
Workflow
MAR without Metal
3D Volume
Reconstruction
Projections
Projections
3D Volume
Input
MAR Workflow
Artem Amirkhanov
7
Attenuation coefficient
thresholding
Artem Amirkhanov
8
Material Separation
Initial
Data
Initial Reconstruction
3D Volume
Metal
3D Volume
Without Metal
Projections
Metal Interpolated
Projection
MAR Volume
3D Volume
Input
Output
Reconstruction
Material Separation
Forward Projection
Interpolation
Fusion
Workflow
MAR without Metal
3D Volume
Reconstruction
Projections
Projections
3D Volume
MAR Workflow
Artem Amirkhanov
9
Artem Amirkhanov
Forward Projection
Works as follows:
Project
every metal
voxel
on
every projection
X
-
ray source
Specimen
Projection
Rotary plate
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11
Forward Projection
Projection
Metal
voxel
projection
Voxel center
Length of projected voxel diagonal
Covered pixels
Partially covered pixels
We overestimate partially covered pixels
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12
Initial
Data
Initial Reconstruction
3D Volume
Metal
3D Volume
Without Metal
Projections
Metal Interpolated
Projection
MAR Volume
3D Volume
Input
Output
Reconstruction
Material Separation
Forward Projection
Interpolation
Fusion
Workflow
MAR without Metal
3D Volume
Reconstruction
Projections
Projections
3D Volume
MAR Workflow
3D Volume
Metal
Forward Projection
Initial
Data
Initial Reconstruction
3D Volume
Metal Interpolated
Projection
MAR Volume
3D Volume
Input
Reconstruction
Material Separation
Interpolation
Fusion
Workflow
MAR without Metal
3D Volume
Reconstruction
Projections
3D Volume
Artem Amirkhanov
13
Without Metal
Projections
MAR Workflow
Projections
Output
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14
Interpolation
Row
-
wise
linear interpolation along the X axis
Artem Amirkhanov
15
Interpolation
Row
-
wise linear
interpolation along the X axis
Artem Amirkhanov
16
Interpolation
Row
-
wise linear
interpolation along the X axis
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17
Interpolation
Row
-
wise
linear interpolation along the X axis
Start of the gap
End of the gap
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18
Interpolation
Row
-
wise linear
interpolation along the X axis
Start of the gap
End of the gap
Initial
Data
Initial Reconstruction
3D Volume
Metal
3D Volume
Without Metal
Projections
Metal Interpolated
Projection
MAR Volume
3D Volume
Input
Output
Reconstruction
Material Separation
Forward Projection
Interpolation
Fusion
Workflow
MAR without Metal
3D Volume
Reconstruction
Projections
Projections
3D Volume
MAR Workflow
Artem Amirkhanov
19
Artem Amirkhanov
20
Initial
Data
Initial Reconstruction
3D Volume
Metal
3D Volume
Without Metal
Projections
Metal Interpolated
Projection
MAR Volume
3D Volume
Input
Output
Reconstruction
Material Separation
Forward Projection
Interpolation
Fusion
Workflow
MAR without Metal
3D Volume
Reconstruction
Projections
3D Volume
MAR Workflow
Artem Amirkhanov
21
Fusion
Interpolation on the metal boundaries for smooth
appearance
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Integrated Visual Analysis Tool
Steps of the workflow
are integrated
Visual threshold
estimation
Segmentation preview
Result preview
Visual result exploration
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23
Results (1)
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24
Results (1)
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25
Results (2)
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26
Results (2)
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27
Results (3)
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28
Results (3)
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29
Limitations
Interpolation introduces
blurring
in the result
Limiting factor:
metal projected area
Artem Amirkhanov
30
Limitations
Interpolation introduces
blurring
in the result
Limiting factor:
metal projected area
Artem
Amirkhanov
31
Conclusions
MAR for 3D industrial MMCs
Significant artifact reduction
Works for various datasets
Integrated visual analysis tool
Assisting user in threshold estimation
Exploring the result
GPU implementation (CUDA)
Reconstruction
Forward
-
projection
Interpolation
Artem Amirkhanov
32
Conclusions
Thank you!
VS
Contact:
artem@cg.tuwien.ac.at
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