| This thesis studies the clinical feasibility of pinhole SPECT with iterative reconstruction. The Median Root Prior (MRP), a Bayesian Maximum A Posteriori (MAP) filter, is used to reduce high frequency noise while preserving edges. The prior weight, beta, is varied over the full range from zero to one.; High activity line and thyroid phantoms were imaged to study the system's abilities. A wrist was also imaged under realistic conditions to demonstrate clinical feasibility.; The iterative reconstruction with the MRP filter proved to be robust, yielding the correct geometry without serious artefacts. The average spatial resolution with a moderate amount of filtering (beta = 0.3) was 6.0 +/- 0.3 mm. The uniformity of hot backgrounds is better than 6% with beta ≥ 0.1. All cold and hot spots in the thyroid phantom were visible in all reconstructions. The wrist image, although count limited, demonstrates a clinical potential for pinhole SPECT. (Abstract shortened by UMI.)... |
