Method for determining beam hardening corrected sinogram values in X-ray computed tomography examination, involves recording logarithmized sinogram data for radiation by wedge filter or phantom, and calculating theoretical sinogram data

摘要

The method involves recording multiple logarithmized sinogram data for radiation (R) with different radiography lengths by a wedge filter (4) made of aluminum, carbon or Teflon (RTM: Polytetrafluoroethylene) and by the phantom (P) made of Plexiglass (RTM: Polymethyl methacrylate) with a detector (3) with computed tomography by using an eccentrically arranged single convex edge free phantom. The theoretical sinogram data for the radiation is calculated from the geometric information of the wedge filter and of the phantom. The correction coefficients are determined by comparison of the theoretic logarithmic sinogram data with the measured logarithmized sinogram data depending on existing degradation by the wedge filter and measured sinogram values. Independent claims are included for the following: (1) a method for determining a beam hardening corrected computed tomography imaging data set in X-ray computed tomography examination by using a wedge filter; (2) a method for reconstructing a beam hardening corrected computed tomography imaging data set in X-ray computed tomography examination using a wedge filter; and (3) a computing system for use in a computed tomography system for image reconstruction.