Purpose: The goal of this study was to evaluate the accuracy of gated single photon emission computed tomography (SPECT) in the assessment of left ventricular (LV) end-diastolic/end-systolic volumes (EDV, ESV) and ejection fraction (LVEF) in patients with dilated cardiomyopathy, using cardiac magnetic resonance imaging (MRI) as the reference method. Furthermore, software-specific characteristics of Quantitative Gated SPECT (QGS), Emory Cardiac Toolbox (ECTB) and 4D-MSPECT were analysed.
Methods: Thirty-six patients with dilated cardiomyopathy who underwent gated (99m)Tc-methoxyisobutylisonitrile SPECT and cardiac MRI were included. LV EDV, ESV and LVEF values of gated SPECT were calculated using QGS, ECTB and 4D-MSPECT.
Results: The correlation between the results of gated SPECT and cardiac MRI was excellent for EDV [R = 0.872 (QGS), R = 0.879 (ECTB), R = 0.869 (4D-MSPECT)], ESV [R = 0.908 (QGS), R = 0.897 (ECTB), R = 0.880 (4D-MSPECT)] and LVEF [R = 0.794 (QGS), R = 0.763 (ECTB), R = 0.710 (4D-MSPECT)]. EDV and ESV assessed by QGS did not differ significantly from those assessed by cardiac MRI (all p = NS), whereas EDV and ESV were overestimated by ECTB and 4D-MSPECT compared with cardiac MRI (all p < 0.05). LVEF was overestimated by QGS, ECTB and 4D-MSPECT compared with cardiac MRI (all p < 0.05).
Conclusions: The correlation between gated SPECT and cardiac MRI is excellent for LV volume and LVEF values calculated by QGS, ECTB and 4D-MSPECT in patients with dilated cardiomyopathy. However, algorithm-varying over- or underestimation of LV volumes and LVEF should be accounted for in the clinical context.