- 1 Artifact Reduction
- 1.1 Ring artifact reduction
- 1.2 Vertical artifact reduction
- 1.3 Metal artifact reduction
- 1.4 Cupping artifact reduction (beam-hardening reduction)
TomoShop® has strong tools for reducing various type of artifacts and noises.
As you can see the below CT reconstruction Images from Flat Panel detector, there are ring artifacts and noises. Using Reduction tools of Ring artifacts on TomoShop®, the ring artifacts and noises in the CT reconstruction images are reduced.
☟ Video for reducing ring artifact by TomoShop®
The CT reconstruction images from Flat Panel detector is shown below. There are vertical artifacts and noises. Using Reduction tools of Vertical artifacts on TomoShop®, the vertical artifacts and noises are reduced.
☟ Video for reducing ring and vertical artifact by TomoShop®
Countermeasures for ring artifacts occurred from variations in detector element sensitivity or defective pixels
Ring artifact / vertical artifact may occur due to defective elements in the detector or uneven reception sensitivity. In X-ray CT, regular ring artifacts
occur on concentric circles of the actual CT scan trajectory, however, certain ring artifacts may not occur on that concentric circle. This is a case that is common in ring artifacts that occur when there are geometric errors in the actual CT scan trajectory and it does not become circumference, the characteristic of the artifact is not a ring of concentric circles. These ring artifacts can not be reduced by conventional artifact reduction methods.
TomoShop®’s artifact reduction function is developed from state-of-the-art image processing technology matching the characteristics of X-ray images. It is possible to estimate variations in detector element sensitivity at the same time as detecting defective pixel map of X-ray CT projection images beforehand and use those information at the time of reconstruction to reduce more effectively and more powerful ring artifacts / vertical artifacts.
Reduction of ring artifacts existing in non-concentric circles of CT scan trajectory
Ring artifacts that are not concentric circles of the CT scan trajectory occur when there are error in the actual CT scan trajectory and its shape does not become circumference. It is impossible to reduce those type of ring artifacts by conventional artifact reduction methods. The artifact reduction function of TomoShop effectively and strongly reduces those ring artifacts even if the scan trajectory is not circumference, by using defective pixel information and sensitivity variation information at the reconstruction stage.
Ring artifact not on concentric circle:
Metal artifacts occur when the sample contains metals in the CT reconstruction images. It disturbs accuracy of inspection.
TomoShop® has strong metal artifact reduction tools that reducing metal artifacts strongly in the CT reconstruction images and it enable to present more clear and accurate CT reconstruction mages as CT scan result.
☟ Video for metal artifact reduction by TomoShop®
One of the big issue is Cupping Artifacts for X-ray CT system. It is very difficult to deal with this noises by modern X-ray CT technology. However, TomoShop can provide the solution of this tricky issue.
The problems caused by cupping artifact (beam-hardening problem) are:
- Impossible to examine the area where cupping artifact is occurring.
- Causing problem with displaying the accurate situation of the samples.
- Causing problem with 3D measurement. Unable to get accurate value for measuring.
The CT reconstruction software TomoShop® series have the cupping artifact reduction (cupping effect reduction) tools for solving this problems in CT reconstruction images.
Cupping artifact (Beam-hardening) is reduced, so that you can see the area where covered by cupping artifact (edge part) and accurate shape of the sumple clearly.
Cupping artifact (Beam-hardening) covered the area where you can not see the surface or accurate shape.
☟ Video for cupping artifact reduction (Beam-hardening) by TomoShop®