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Instrumentation & Data Analysis: InstrumentationSPECT |
1 Institute of Nuclear Medicine, UCL, London, United Kingdom
499
Objectives: We aim to design a brain SPECT system on the hypothesis that acquiring data with mixed degrees of multiplexing facilitates high quality reconstruction. We consider the efficiency / resolution tradeoff for a range of designs that satisfy this requirement.
Methods: Three basic designs have been compared for a 1mm intrinsic resolution detector a) an asymmetric rotating slit-slat collimator (ARC) b) an asymmetrically rotating detector assembly (ARD) c) a symmetric rotating slit-slat collimator with variable-spaced slits (SRC). We modelled the slit-slat collimator analytically as a parallel-hole collimator in the axial dimension and a pinhole in the trans-axial dimension. Assuming a continuous cylindrical detector system, and for a fixed average percentage overlap we compare the three systems in terms of system efficiency and resolution at the centre of the field-of-view.
Results: Results are presented in the table below. For the same average percentage overlap, the best compromise was obtained with the SRC which had best efficiency and well balanced axial and trans-axial resolution. Further optimization is possible for this system.
Conclusions: These results demonstrate that the system with symmetric collimator rotation provides a good compromise between efficiency and resolution and also provides the best practical solution to facilitate varied multiplexing.
Research Support: GE Healthcare, EPSRC, EC FP6
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