Algebraic and Statistical Reconstruction Methods

Abstract

Currently, the filtered backprojection (FBP) method, which has been discussed in Sect. 5.7, is the reconstruction algorithm of choice because it is very fast, especially on dedicated hardware. However, one disadvantage of FBP is that it essentially weights all X-rays equally. Since X-ray tubes produce a polychromatic spectrum, beam-hardening image artifacts arise in the reconstruction. Artifacts of this type are particularly dominant if metal objects are inside the patient, because FBP interprets the corresponding projection data as inconsistent. Here, algebraic and statistical reconstruction methods will serve as alternatives because artificial or inherent beam weighting reduces the influence of rays running through metal objects.