Patent ID: 7840043

Claim:
A method for an X-ray machine for determining a parameter in an image area as a measure of a homogeneity of a substance in an object, the method comprising: acquiring two X-ray images that have attenuation values Di(E 1 ),Di(E 2 ), where i=1 . . . N, that represent an attenuation of the X-radiation passing through the object, for at least two different energies E 1 , E 2 of an X-radiation; forming, in the image area, measured value pairs (D 1 (E 1 ),D 1 (E 2 )), . . . , (DN(E 1 ),DN(E 2 )) for corresponding pixels Di from the attenuation values Di(E 1 ) of the X-ray image acquired in relation to the first energy E 1 of the X-radiation, and from the attenuation values Di(E 2 ) of the X-ray image acquired in relation to the second energy E 2 of the X-radiation; and determining the parameter as a measure of the homogeneity of the substance of the object, respective to an area surrounding the object, by evaluating a statistical distribution of the measured value pairs (D 1 (E 1 ),D 1 (E 2 )), . . . ,(DN(E 1 ),DN(E 2 )) of the image area.