Novel Cadmium Zinc Telluride Based detector General Purpose Gamma Camera: Initial Evaluation and Comparison with a Standard Camera

259 Objectives To prospectively compare the first of its kind Cadmium Zinc Telluride (CZT) based general purpose gamma camera (CZT-camera), with a standard NaI based camera (NaI-camera) in patients referred for scintigraphic investigations. The CZT-camera (Discovery NM/CT 670 CZT, GE Healthcare) has a pixelated detector of a size of 2.46 mm/pixel and energy resolution of 6.3% while the NaI-camera (Discovery NM/CT 670, GE Healthcare) has an energy resolution of 9.8%. Methods Nineteen patients (9 men, age range 18 - 84y) who were referred for Nuclear Medicine (NM) imaging procedures as part of their clinical assessment were prospectively recruited. The studies included Tc99m-MDP bone scintigraphy (7), one day, single isotope Tc99m-MIBI myocardial perfusion imaging (MPI) (3), Tc99m thyroid (3), Tc99m-MAA lung (2), Tc99m-DMSA renal (2) and Tc99m-MIBI parathyroid (2) scans. First, the patients underwent the standard scintigraphic procedure according to the specific routine protocol using the dual head NaI-camera (Discovery NM/CT 670, GE Healthcare). Immediately after the completion of the study on the NaI-camera, patients were rescanned with the CZT-camera (Discovery NM/CT 670 CZT, GE Healthcare) using the same acquisition protocol. Images generated by the CZT-camera were reconstructed to be displayed using full and 75% acquisition times. Two readers independently scored all studies using a 5-point scale (1=non-diagnostic to 5=excellent) for perceived image quality and spatial resolution. The scores obtained for the two devices were further compared using the Mann-Whitney test with p Results Overall, 29 scans were performed on each device including 18 planar and 11 SPECT studies. The average image quality and spatial resolution scores in the full time CZT-camera studies were 4.83 and 4.83 respectively. These values were significantly higher than the scores obtained with the NaI-camera (4.64 and 4.43, p Conclusions These preliminary results suggest that the CZT-based general purpose gamma camera provides higher diagnostic performance as compared to the standard NaI-based camera when using the same acquisition parameters. A 25% decrease in acquisition time can be implemented on the CZT-based camera without any compromise in image quality and resolution. Future studies will assess whether time reduction can potentially interchange with lower injected dose.