title: Collimator design for improved spatial resolution in SPECT and planar scintigraphy.
abstract: This paper evaluates the design of a new planar-concave collimator with nonuniform response that better matches the body shape than conventional collimators.
  
  
  METHODS
  The collimator properties are evaluated and assessed by means of both a stimulation program and an experimental test using a prototype planar-concave collimator.
  
  
  RESULTS
  The results, for points located 150 mm from the axis of rotation, demonstrate that the ratio of radial and tangential spatial resolution in SPECT with the new collimator decreased by 40%, as compared to SPECT with a standard collimator. In planar scintigraphy, the spatial resolution improved correspondingly from 10.9 mm (FWHM) to 7.8 mm in lateral areas of the body.
  
  
  CONCLUSIONS
  The new collimator reduces nonisotropic blurring in SPECT in addition to improving spatial resolution in both planar scintigraphy and in SPECT.
authors.affiliation: Department of Hospital Physics, Karolinska Hospital, Stockholm, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Kimiaei
authors.forename: S A
authors.initials: SA
authors.lastname: Larsson
authors.forename: H
authors.initials: H
authors.lastname: Jacobsson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001842:Bone and Bones / Q000000981:diagnostic imaging; D003198:Computer Simulation; D004867:Equipment Design; D015902:Gamma Cameras; D006801:Humans; D008297:Male; D019047:Phantoms, Imaging; D013669:Technetium Tc 99m Medronate; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation*
chemical_list: D013669:Technetium Tc 99m Medronate