title: Simulation of HyperSPECT: a high-resolution small-animal system with in-line x-ray optics.
abstract: SPECT has become an important tool in pre-clinical applications. Small-animal imaging systems based on the use of one or more pinhole collimators now reach sub-half-mm resolution but unfortunately suffer from a compromise between sensitivity and resolution due to the pinhole collimators. We propose a small-animal SPECT system based not on pinholes but on in-line x-ray optics, which is rare in medical imaging systems for nuclear medicine. The x-ray lenses are optimized for 27 keV for low-energy imaging with iodine-125. We believe that this new system, HyperSPECT, can simultaneously improve on sensitivity and resolution compared to today's state-of-the-art systems. A full three-dimensional simulation of the system has been performed including the prism-array lenses, pre- and post-collimators and scintillator-based detector. Images of capillary phantoms have been reconstructed using an iterative image reconstruction method. Sensitivity was uniformly 0.37% throughout the 1 cm diameter spherical field of view and rod sizes of around 100 μm diameter were distinguishable in the images of simulated capillary phantoms. These results indicate an increase in resolution by a factor of 5 during a simultaneous increase in sensitivity by a factor of 2 compared to the current state-of-the-art small-animal SPECT systems.
authors.affiliation: Department of Physics, The Royal Institute of Technology, AlbaNova University Center, 106 91 Stockholm, Sweden. sandra.tibbelin@mi.physics.kth.se
authors.forename: Sandra
authors.initials: S
authors.lastname: Tibbelin
authors.forename: Peter
authors.initials: P
authors.lastname: Nillius
authors.forename: Mats
authors.initials: M
authors.lastname: Danielsson
mesh_terms: D000465:Algorithms; D000818:Animals; D055592:Biophysical Phenomena; D002196:Capillaries / Q000000981:diagnostic imaging; D021621:Imaging, Three-Dimensional; D007457:Iodine Radioisotopes; D023421:Models, Animal; D055096:Optical Devices; D055620:Optical Phenomena; D019047:Phantoms, Imaging; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data
chemical_list: D007457:Iodine Radioisotopes