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Analytical calculation of photon distributions in SPECT projections

University of British Columbia

In this work is presented a method for analytically calculating the distribution of photons detected in SPECT projections. The technique is applicable to sources in homogeneous and non-homogeneous media. The photon distribution (primary, first and second order Compton scatter, and first order Rayleigh scatter) is computed using precalculated camera-dependent lookup tables in conjunction with an attenuation map of the scattering object and a map of the activity distribution. The results of the technique are in excellent agreement with those of Monte Carlo simulation and experimental phantom studies. It has been validated with respect to sources in both homogeneous and non-homogeneous media. Compared with a similar analytical technique, it offers a factor of 40-60 decrease in the calculation time for higher order Compton scatter distributions. For small sources, it improves on computation time required by Monte Carlo simulators by a factor of 20-150. Finally, this method has been applied to the problem of correcting for cross-talk in 1 2 3I-9 9 mTc dual-isotope SPECT studies. It has demonstrated the ability to accurately reproduce the shape of the cross-talk distribution and to reproduce the absolute activity of the sources to within 7%, allowing accurate removal of cross-talk contamination.

Thesis/Dissertation

application/pdf

2009-04-17

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http://hdl.handle.net/2429/7334

Physics

University of British Columbia

UBCV

DSpace