2016_Imaging for Physicists

Other artifacts

• Ghosting – Detector after-glow from previous exposure • Aliasing – Undersamplig of voxels far from the source due to the cone shape of the beam – Cause the commonly seen lines from the center to the peripheral part of the image • Patient motion • Non-ideal gantry rotation Schulze et al. 2011

– Variation in gantry rotation speed – Sag of detector and/or X-ray source

Corrected

Not corrected

Rit et al. 2008