title: Cone beam collimation for single photon emission computed tomography: analysis, simulation, and image reconstruction using filtered backprojection.
abstract: This paper presents an analysis of two cone beam configurations (having focal lengths of 40 and 60 cm) for the acquisition of single photon emission computed tomography (SPECT) projection data. A three-dimensional filtered backprojection algorithm is used to reconstruct SPECT images of cone beam projection data obtained using Monte Carlo simulations. The mathematical analysis resulted in on-axis point source sensitivities (calculated for a distance of 15 cm from the collimator surface) for cone beam configurations that were 1.4-3 times the sensitivities of parallel-hole and fan beam geometries having similar geometric resolutions. Cone beam collimation offers the potential for improved sensitivity for SPECT devices using large-field-of-view scintillation cameras.
mesh_terms: D006801:Humans; D008433:Mathematics; D009010:Monte Carlo Method; D013679:Technology, Radiologic; D014055:Tomography, Emission-Computed / Q000295:instrumentation / Q000379:methods*