Performance evaluation of D-SPECT: a novel SPECT system for nuclear cardiology

TLDR

D‑SPECT is a novel cardiac perfusion SPECT system that uses CZT detectors, region‑centric scanning, high‑sensitivity collimators, and resolution recovery to potentially outperform conventional systems. The study aimed to evaluate the β‑version D‑SPECT’s performance in energy resolution, scatter fraction, sensitivity, count‑rate capability, and spatial resolution. Performance was assessed by measuring these parameters on the D‑SPECT and on a conventional SPECT system for comparison. D‑SPECT achieved superior energy resolution (5.5 % vs 9.25 %), lower scatter fraction (30 % vs 34 %), higher planar sensitivity (398 s⁻¹ MBq⁻¹ vs 72 s⁻¹ MBq⁻¹), higher tomographic sensitivity (647–1107 s⁻¹ MBq⁻¹ vs 141 s⁻¹ MBq⁻¹), linear count rate up to 1.44 M s⁻¹, intrinsic resolution of 2.46 mm vs 3.8 mm, reconstructed resolution of 12.5 mm vs 13.7 mm, and overall superior sensitivity with comparable spatial resolution, making it suitable for dynamic and dual‑radionuclide studies.

Abstract

D-SPECT (Spectrum Dynamics, Israel) is a novel SPECT system for cardiac perfusion studies. Based on CZT detectors, region-centric scanning, high-sensitivity collimators and resolution recovery, it offers potential advantages over conventional systems. A series of measurements were made on a β-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.