Theoretical resolution of computed tomography systems

A simple analytic model is presented which is used to calculate the impulse response of a computed tomography system for parametric variations of the geometry. The model is useful for fan beam as well as parallel beam geometries. Results show that wide-aperture detector systems have intrinsic resolution limitations that are not mitigated by oversampling. Furthermore, the optimum focal spot size of the X-ray source is found to be dependent on the detector geometry.