<p>A gamma ray collimator for use in a cardiac inspections system is disclosed which resolves energetically unperturbed gamma rays emitted from a patient and removes inelastic scattered gamma rays. A plurality of collimator elements each have walls, with each wall defining a plane comprised of a first material layer covered by a second material layer and absorbing inelastic scattered gamma rays, the planes being parallel to a central longitudinal axis in each of the collimator elements. The walls of each collimator element define an elongated longitudinal passageway having open ends through which the energetically unperturbed gamma rays enter and leave. The first material layer has a large absorption coefficient for gamma rays, and the second material layer has a large absorption coefficient for inelastically scattered gamma rays generated in the first material layer responsive to gamma rays emitted from the patient.</p>
