1. Review influence of increasing longitudinal (z-axis) coverage of CT scanners on the x-ray scatter levels.
2. Review Image quality effects of scattered radiation.
3. Review anti-scatter grids and its impact on overcoming x-ray scatter.
4. Demonstrate a simple phantom setup with supporting images to quantify x-ray scatter.
- X-ray scatter fundamentals
- Influence of scatter with longitudinal coverage of CT scanners
- Impact of scatter on image quality:
o Inaccuracy in reconstructed CT attenuation measurements
o Degradation of contrast-to-noise ratio
- Anti-scatter grid fundamentals
- Phantom setup to observe effect of scatter
- Quantification of scatter
- Sample images to demonstrate impact of anti-scatter grids
The major teaching points of this exhibit are:
1. Increased x-ray scatter as a function of increasing longitudinal coverage of CT scanners.
2. Scattered radiation causes detected signals to deviate from the true measurement of primary x-ray intensity and may result in artifacts.
3. Experimental setup to observe impact of anti-scatter grids on overcoming degradation of image quality in wide coverage CT scanners.
Miyashita, S,
Tokuyasu, S,
Impact of Anti-scatter Grids in Overcoming Image Artifacts Caused by Increased X-ray Scatter in Wide Coverage CT Scanners. Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL.
http://archive.rsna.org/2010/9007498.html