Patent ID: 7134787

Claim:
A method of CT beam hardening calibration comprising: a step of obtaining raw data of a first phantom and a second phantom by scanning the first phantom and the second phantom respectively; a step of calculating a first filter material length and a second filter material length according to one or more spectrum functions and the raw data of the first phantom and the second phantom; a step of adjusting the spectrum function to make the first filter material length and the second filter material length agree with predefined conditions; a step of calculating a beam hardening curve according to the adjusted spectrum function and the first filter material length as well as the second filter material length met with the predefined conditions; a step of processing the raw data by the calculated beam hardening curve to eliminate beam hardening effects; wherein the step of adjusting the spectrum function to make the first filter material length and the second filter material length meet with predefined conditions comprises: judging if an absolute value of the difference between the first filter material length and the second filter material length is less than a predefined threshold; and adjusting the spectrum function according to following equation if the judging result is negative: Spectrum( n,e )=Spectrum Initial ( n,e )×(AdjustS( e )) X(n) where Spectrum Initial (n,e) is an initial spectrum function; AdjustS(e) is a spectrum adjusting function; and X(n) is an adjusting parameter.