Koji Sasaki RT, Presenter: Nothing to Disclose

Soji Miyashita RT, Abstract Co-Author: Nothing to Disclose

Shinichi Tokuyasu RT, Abstract Co-Author: Employee, Koninklijke Philips Electronics NV

Tsuyoshi Osonoi, Abstract Co-Author: Employee, Koninklijke Philips Electronics NV

Dhruv Mehta MS, Abstract Co-Author: Employee, Koninklijke Philips Electronics NV

Understand image quality impact of scattered x-ray, particularly the shift in Hounsfield units Demonstrate impact through low-contrast phantoms and representative clinical examples Understand differences between beam hardening and scatter induced deviations in measurements Review techniques to reduce influence of scatter

Image quality impact of scattered x-ray: X-ray scatter fundamentals Phantom setup to assess scatter under different conditions Phantom images & representative clinical examples to visualize the image quality impact Influence of scanned object size Differentiating beam hardening and scatter artifacts   Approaches of scatter correction: Hardware approaches: 2- and 3- dimensional physical anti-scatter grids Software techniques: Techniques utilizing beam path tracing and Monte

The major teaching points of this exhibit are: 1. The extent of x-ray scatter occurring during an acquisition can be captured/visualized using phantom setups 2. Understanding scatter induced artifacts will help better understand factors that influence the extent of variability in Hounsfield units 3. Consistency in Hounsfield unit measurements obtained through different scatter correction techniques  

Sasaki, K, Miyashita, S, Tokuyasu, S, Osonoi, T, Mehta, D, Quantitative Imaging: Dependence of CT Hounsfield Measurements on Extent of X-ray Scatter.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11020088.html