Performance evaluation of D-SPECT

D-SPECT (Spectrum Dynamics, Israel) is a novel SPECT system for cardiac perfusion studies. Based on CZT detectors, region-centric scanning, highsensitivity collimators and resolution recovery, it offers potential advantages over conventional systems. A series of measurements were made on aβ-version D-SPECT system in order to evaluate its performance in terms of energy resolution, scatter fraction, sensitivity, count rate capability and resolution. Corresponding measurements were also done on a conventional SPECT system (CS) for comparison. The energy resolution of the D-SPECT system at 140 keV was 5.5% (CS: 9.25%), the scatter fraction 30% (CS: 34%), the planar sensitivity 398 s−1 MBq−1 per head (99mTc, 10 cm) (CS: 72 s−1 MBq−1), and the tomographic sensitivity in the heart region was in the range 647– 1107 s−1 MBq−1 (CS: 141 s−1 MBq−1). The count rate increased linearly with increasing activity up to 1.44 M s−1. The intrinsic resolution was equal to the pixel size, 2.46 mm (CS: 3.8 mm). The average reconstructed resolution using the standard clinical filter was 12.5 mm (CS: 13.7 mm). The D-SPECT has superior sensitivity to that of a conventional system with similar spatial resolution. It also has excellent energy resolution and count rate characteristics, which should prove useful in dynamic and dual radionuclide studies. (Some figures in this article are in colour only in the electronic version)