Optimal design of planar-concave collimators for SPECT--an analytical approach.
In this paper we present an analytical tool for the design and optimization of planar-concave collimators for SPECT. We conclude that a single general planar-concave collimator that eliminates the non-isotropic blurring for all SPECT applications does not exist. On the other hand, it is possible to achieve pseudo-optimal collimators for different clinical applications by a careful choice of the design parameters. By classifying the clinical applications into two groups, for instance body and brain studies, the non-isotropic blurring for most SPECT situations may be dramatically reduced by means of planar-concave collimators. The results based on Monte Carlo simulations show that the shape of the point source response function of the reconstructed image obtained from the planar-concave collimator is more isotropic than that obtained from a conventional parallel-hole collimator. Specifically, the ratio of the FWHM of the reconstructed point response function in the radial and tangential direction is increased from 0.5 for the parallel-hole to 0.85 for the planar-concave collimator for sources 200 mm away from the centre of rotation.
Kimiaei
S
S
Department of Hospital Physics, Karolinska Hospital, Stockholm, Sweden. sk@nucmed.ks.se
Larsson
S A
SA
D000465:Algorithms; D055592:Biophysical Phenomena; D001703:Biophysics; D001921:Brain / Q000000981:diagnostic imaging; D003198:Computer Simulation; D004867:Equipment Design; D006801:Humans; D008962:Models, Theoretical; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation* / Q000706:statistics & numerical data