%0 Journal Article %A Nathaniel Roth %A Robert Eisner %A Samy Bross %A Rafael Baavour %T Improved thallium-201 image contrast with a novel CZT cardiac SPECT system %D 2009 %J Journal of Nuclear Medicine %P 1499-1499 %V 50 %N supplement 2 %X 1499 Objectives To validate an optimized energy window - 65keV to 84keV - for 201Tl imaging with a novel CZT cardiac SPECT system. Methods List mode phantom and patient data were acquired, reconstructed and processed identically both with optimized energy window (65 to 84keV) and standard energy window (70keV±15%) on the D-SPECT (Spectrum-Dynamics, Caesarea, Israel). An anthropomorphic phantom with a 2cm defect (DSC, Model ECT/TOR/P) was analyzed. In addition, 4minute, stress 201Tl scans from 20 patients (10 females) with low probability of disease and 10 patients with myocardial defects were analyzed. “Myocardial wall to cavity” and “myocardial wall to defect” contrast measurements were obtained from profile analysis on short axis slices. “Myocardial wall to cavity” contrast was calculated using average maximum septal and lateral wall counts (ASLW) and minimum cavity counts (C) as [ASLW-C]/ASLW. “Myocardial wall to defect”contrast was calculated using maximum wall counts (W) and maximum defect counts (D) as [W-D]/W. Results The optimized 201Tl energy window (65 to 84keV) improved phantom and patient “myocardial wall to defect” contrast by 21.5% and 23.2%±13.5% (p<0.0001) respectively and the “myocardial wall to cavity” contrast by 4.9% and 6.6%±4.1% (p<0.0001) respectively. Results are detailed in the following table: Conclusions By taking advantage of the superior CZT energy resolution of the D-SPECT an optimized 201Tl energy window has been defined which increases image contrast significantly. %U