Head-to-head performance comparison of dedicated vs. general-purpose gamma cameras during gated and perfusion myocardial scintigraphy

Abstract

Abstract Background Comparison of the performance of a conventional, Anger-system, general-purpose SPECT/CT (AnyScan SC FLEX) vs. an Anger-system dedicated cardiac SPECT (CardioC) camera for gated myocardial perfusion imaging. Method Fifty patients were enrolled into the study. Of these, myocardial perfusion scintigraphy with 450 MBq SestaMIBI (Mediradiopharma) was performed after dipyridamole stress testing in 43, and at rest in the remaining 7 patients. ECG-gated SPECT acquisition was undertaken with both cameras, with a scanning time of 16 minutes. Within 45 to 60 minutes of the intravenous administration of the radiopharmaceutical, imaging was done first with the CardioC and then – after 30 minutes on average – with the AnyScan SC FLEX camera. The sensitivity of the systems (uptake of the radiotracer by the heart), severity of perfusion defects (SS), and parameters of left ventricular volume and wall motion (EF, EDV, ESV, SV, and cardiac mass) were determined quantitatively with both cameras. All these indices were then compared and the results were subjected to statistical analysis. Results Sensitivity (the scintillation counts recorded within the ROI cardiac projection) was 17.8% (median) higher with the AnyScan FLEX than with the CardioC camera (p < 0.001). There was no meaningful difference between the two cameras in assessing the severity of the perfusion abnormality (p > 0.1). The EF obtained after attenuation correction was significantly lower than without AC. The volume estimates significantly depended on the camera and reconstruction method (p < 0.001); especially, with the FLEX camera the EDV and SV estimates were significantly lower. Attenuation correction of the FLEX images resulted in the lowest estimated myocardial mass(p = 0.004 against the values obtained with CardioC). Conclusions The results support our initial assumption that when used formyocardial perfusion imaging, the performance of general-purpose, digital, hybrid SPECT/CT cameras and dedicated cardiac scanners (both with parallel-hole collimators) is similar in the case of conventional Anger-system devices.