Dual energy CAT scan

A technique for increasing imaging contrast between dissimilar tissues.  Biological tissues attenuate X ray beams to differing extents depending on (a) the nature of the tissue and (b) the energy of the X ray beam. First generation CAT scanners used X ray at a single energy level. By using two X ray sources, at differing energy levels (dual energy technique), contrast definition between tissues and therefore image resolution can be improved.