Cone beam effect

Cone beam effect artifacts are seen in multidetector row CT (cone beam CT) acquisitions . 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. 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  which can lead to under-sampling in the cone angle dimension. This causes noise, streaks and stair-step artifacts . The artifacts are more pronounced at the periphery of the field of view and worsen with an increasing number of detector rows .

The problems of cone beam effects have been addressed by the use of cone beam reconstruction techniques instead of standard reconstruction. The artifact is also minimized by ensuring a well-sampled environment .