Projection generation Object/ Phantom f(x,y) Sinogram, p(t,  ) t  Projection, p(t,  =0) 

Filtered backprojection Filtered sinogram Sinogram Ramp filter Sum of all backprojections One backprojection t 

Backprojection, movie

A modern CT-system gives fanbeam projection data X-ray source Detector Detector Electronics High VoltageProjektion data Slip rings

Advanced CT-system 2004 n 0.5 mm/voxel n 2 r/s n 64 detektor rows n 64 rows * 900 elements * 1200 projections * 2 r/s * 3 B = 415 MB/s