CT SYSTEM ENERGY SPECTRUM INCONSISTENCY CORRECTION METHOD

摘要

Disclosed is a CT system energy spectrum inconsistency correction method, comprising: carrying out self-adaptive estimation on the thickness of a non-uniform filter by means of a measured transmission value of the non-uniform filter and an effective energy spectrum of a CT system without the non-uniform filter so as to obtain an equivalent thickness of the non-uniform filter at the position of each detector unit (S23); establishing a hardening function relationship between a polychromatic projection value of the CT system and a monochromatic projection value thereof according to a linear attenuation coefficient and thickness information of an object and the equivalent thickness of the non-uniform filter at the position of each detector unit, and obtaining a hardening correction lookup table according to the hardening function relationship (S24); and correcting, according to the hardening correction lookup table of each detector unit, the polychromatic projection value of a detector to the corresponding monochromatic projection value (S25). The correction method eliminates a CT system energy spectrum inconsistency, and is applicable not only to the processing of a static spatial non-uniform filter but also to that of a dynamic temporal non-uniform filter.