Variability introduced by the operator in processing myocardial Gated-SPECT studies

Abstract

Introduction – Gated - Single Photon Emission Computed Tomography (SPECT) is one of cardiac imaging techniques with more development over last decades. For image analysis, the use of quantification software leads to increased reproducibility and accuracy of interpretations. The purpose of this study was to assess, in Gated-SPECT studies, intra and inter-operator variability of quantitative parameters of myocardial perfusion and function, obtained with the software Quantitative Gated SPECT (QGS) and Quantitative Perfusion SPECT (QPS). Material and methods – We used a non-probability sample of convenience of 52 patients who underwent myocardial Gated-SPECT studies for clinical indications and that formed ESTeSL’s Xeleris workstation database. The fifty-two studies were divided into two groups: Group I (GI) of 17 patients with normal myocardial perfusion images; Group II (GII) of 35 patients with perfusion defects in Gated-SPECT images. All studies were processed 5 times by 4 independent operators (with 3 years of experience in Nuclear Medicine Services with a sample mean of 15 Gated-SPECT studies per week). Friedman´s statistical test was used to assess intra and inter-operator variability, considering α = 0.01. Results and discussion – To all variables, the respective p values did not reflected statistically significant differences (p> α). Thus, there was no significant intraor inter-operator variability in processing myocardial Gated-SPECT studies. Conclusion – QGS and QPS software allow a reproducible quantification of the evaluated function and perfusion parameters, with no variability introduced by the operator.

Keywords

• Gated-SPECT, parâmetros quantitativos, reprodutibilidade, variabilidade inter- -operador, variabilidade intra-operador