title: An efficient pre-object collimator based on an x-ray lens.
abstract: A multiprism lens (MPL) is a refractive x-ray lens with one-dimensional focusing properties. If used as a pre-object collimator in a scanning system for medical x-ray imaging, it reduces the divergence of the radiation and improves on photon economy compared to a slit collimator. Potential advantages include shorter acquisition times, a reduced tube loading, or improved resolution. We present the first images acquired with a MPL in a prototype for a scanning mammography system. The lens showed a gain of flux of 1.32 compared to a slit collimator at equal resolution, or a gain in resolution of 1.31-1.44 at equal flux. We expect the gain of flux in a clinical setup with an optimized MPL and a custom-made absorption filter to reach 1.67, or 1.45-1.54 gain in resolution.
authors.affiliation: Department of Physics, Royal Institute of Technology, AlbaNova, SE-106 91 Stockholm, Sweden. fberg@mi.physics.kth.se
authors.forename: Erik
authors.initials: E
authors.lastname: Fredenberg
authors.forename: Björn
authors.initials: B
authors.lastname: Cederström
authors.forename: Magnus
authors.initials: M
authors.lastname: Aslund
authors.forename: Peter
authors.initials: P
authors.lastname: Nillius
authors.forename: Mats
authors.initials: M
authors.lastname: Danielsson
mesh_terms: D006801:Humans; D007909:Lenses; D008327:Mammography / Q000295:instrumentation; D011859:Radiography / Q000295:instrumentation*; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D014965:X-Rays