Patent ID: 6652143
Filing Date: 2003-11-25
Classification: A61B,G01N,H05G

Abstract:
A method for dynamically measuring a position, shape, size and intensity distribution of an effective focal spot on an anode of an x-ray tube, wherein at least one of said position, shape, size and intensity distribution changes with respect to time, comprising the steps of:theoretically dividing said focal spot into a plurality of elementary radiators; providing a detector array having a resolution, said detector array being composed of a plurality of detector elements, each of said detector elements generating an electrical signal dependent on x-rays incident thereon; disposing a micro-hole collimator between said focal spot and said detector array at a distance closer to said focal spot than to said detector array; emitting an x-ray beam from said focal spot which passes through an aperture in said micro-hole collimator to produce a magnified projection of said focal spot on said detector array containing elementary protections produced by overlapping elementary radiators; sampling respective electrical signals from said detector elements while said magnified projection is incident on said detector array, and combining said respective electrical signals to dynamically measure said position, shape, size and intensity distribution of said focal spot; and setting a diameter of said aperture in said micro-hole collimator through which said x-ray beam passes to substantially avoid significant noise in said electrical signals from said detector elements by setting said overlapping to a predetermined amount depending on said detector resolution and a magnification factor associated with said location of said micro-hole collimator.