Cone beam effect artifacts are seen in multidetector row CT (cone beam CT) acquisitions 1. Modern CT scanners use more detector arrays to increase the number of sections acquired per rotation. This causes the x-ray beams to become cone-shaped as opposed to fan-shaped 2. As a result instead of collecting data that corresponds to a flat plane , each detector collects data that corresponds to the volume contained between two cones 2 which can lead to under-sampling in the cone angle dimension 3. This causes noise, streaks and stair-step artifacts 1. The artifacts are more pronounced at the periphery of the field of view and worsen with an increasing number of detector rows 1.
The problems of cone beam effects have been addressed by the use of cone beam reconstruction techniques instead of standard reconstruction 2. The artifact is also minimized by ensuring a well-sampled environment 3.
- 1. F Edward Boas, Dominik Fleischmann. CT artifacts: causes and reduction techniques. (2012) Imaging in Medicine. 4 (2): 229.
- 2. Julia F. Barrett, Nicholas Keat. Artifacts in CT: Recognition and Avoidance1. (2004) RadioGraphics. 24 (6): 1679-91. doi:10.1148/rg.246045065 - Pubmed
- 3. Jerrold T. Bushberg, John M. Boone. The Essential Physics of Medical Imaging. (2011) ISBN: 9780781780575