Physics Bucharest 2017

Conventional CT:

Cone Beam CT: Single gantry rotation with 2D rows/planar detectors ‘cone beam’ poorly collimated with scattered photons results in reduced image quality Also available with 4D mode RT x-ray systems that are integrated with the linear accelerator tend to use cone beam geometry

‘Fan beam’ highly collimated Multiple gantry rotations. Most now multi-slice resulting in broadening of fan beam approaching a cone beam Planning CT scanners and in-room CT scanners traditionally fan beam geometry.