A CMP abrasive comprising a cerium oxide slurry containing cerium oxide particles, a dispersant and water, and a liquid additive containing a dispersant and water; and a liquid additive for the CMP abrasive. A noise overlay unit is provided as a front stage of an error adding unit for adding error to input image data. The method may be incorporated as part of a dual energy image processing chain to create dual energy images with improved image quality and diagnostic performance. The step of grinding the armature assembly may be done after attaching the guide piece and the flux piece together. One elongated mating member includes an actuator mobile axially relative to the elongated mating member between a first position in which the elastic member locks the two elongated mating members axially and a second position in which the actuator unlocks the elongated mating members by radial retraction of the elastic member.