title: Collimation approaches to 511-keV imaging.
authors.forename: A D
authors.initials: AD
authors.lastname: Waxman
mesh_terms: D015902:Gamma Cameras; D006801:Humans; D014055:Tomography, Emission-Computed / Q000295:instrumentation / Q000379:methods*; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation / Q000379:methods*