MONTE-CARLO EVALUATION OF ACCURACY AND NOISE PROPERTIES OF 2 SCATTER CORRECTION METHODS FOR TL-201 CARDIAC SPECT

Two independent scatter correction techniques, transmission dependent convolution subtraction (TDCS) and triple-energy window (TEW) method, were evaluated in terms of quantitative accuracy and noise properties using Monte Carlo simulation (EGS4). Emission projections (primary, sc atter and scatter plus primary) were simulated for three numerical pha ntoms for Tl-201. Data were reconstructed with ordered-subset EM algor ithm including noise-less transmission data based attenuation correcti on. Accuracy of TDCS and TEW scatter corrections were assessed by comp arison with simulated true primary data The uniform cylindrical phanto m simulation demonstrated better quantitative accuracy with TDCS than with TEW (-2.0% vs 16.7%) and better S/N (6.48 vs 5.05). A uniform rin g myocardial phantom simulation demonstrated better homogeneity with T DCS than TEW in the myocardium; i.e., anterior-to-posterior wall count ratios were 0.99 and 0.76 with TDCS and TEW, respectively. For the MC AT phantom, TDCS provided good visual and quantitative agreement with simulated true primary image without noticeably increasing the noise a fter scatter correction. Overall TDCS proved to be more accurate and l ess noisy than TEW, facilitating quantitative assessment of physiologi cal functions with SPECT.