When performing Computed Tomography, a common artifact that frequently pops its ugly head is a ring artifact. A new Hardware/Software solution from NSI nearly eliminates ring artifacts completely while bringing other benefits to the acquisition process.
During a CT scan, pixels that do not respond to the variations in product related attenuation will cause consistent or intermittent tracks along scan trajectories which end up as rings in a CT reconstruction.
Another contributor to this artifact is product position. The area of a part that lands directly on the center of the rotational axis has no real perspective change during rotation. A ring artifact is also very commonly present in this area especially if the image has a lower signal to noise ratio in that area.
2 Comparison Scans were performed with and without the newly developed ring reduction technology. The scans were performed using severe ring artifact causing parameters.
Worst Case Ring Artifact Scan Conditions
- Samples were positioned directly on the center of axis of rotation.
- 4 fps – 2 Frames Averaged (FA) in acquisition
- 4 fps – only 2 FA for Gain and Offset Corrections
Results of the Scan Comparison
- Image Quality Increased
- Reduction of artifacts that can mask indications or be misinterpreted as an indication.
- Improve volume surface quality
- Time Savings On Gain Correction Acquisition
- Reduce # of Gain corrections
- Reduce Gain Acquisition Times
- No increase in scan time
- Increase in Geometric Magnification without Ring Artifact by keeping the sample more to the center of the rotational axis.
- Transparent Use: Routine automatically runs without additional operator involvement.