Assessment of left ventricular volumes, ejection fraction and mass. Comparison of model-based analysis of ECG-gated (⁹⁹m)Tc-SPECT and ¹⁸F-FDG-PET.

Aim: We compared and delineated possible differences of model-based analysis of ECG-gated SPECT using (⁹⁹m)Tc-sestamibi (Tc-SPECT) with ECG-gated ¹⁸F-fluorodeoxyglucose-PET (FDG-PET) for determination of end-diastolic (EDV) and end-systolic (ESV) cardiac volumes, left ventricular ejection fraction (LVEF), and myocardial mass (LVMM).
Patients, Methods: 24 patients (21 men; age: 54±12years) with coronary artery disease underwent Tc-SPECT and FDG-PET imaging for evaluation of myocardial perfusion and viability. By using model-based analysis EDV, ESV, LVEF and LVMM were calculated from short axis images of both Tc-SPECT and FDG-PET.
Results: Left ventricular volumes by Tc-SPECT and FDG-PET were 176±60 ml and 181±59 ml for EDV, and 97±44 ml and 103±45 ml for ESV respectively, LVEF was 47±8% by Tc-SPECT and 45±9% by FDG-PET. The LVMM was 214±40 g (Tc-SPECT) and 202±43 g (FDG-PET) (all p = NS, paired t-test). A significant correlation was observed between Tc-SPECT and FDG-PET imaging for calculation of EDV (r = 0.93), ESV (r = 0.93), LVEF (r = 0.83) and LVMM (r = 0.72).
Conclusion: ECG-gated Tc-SPECT and FDG-PET using two tracers with different characteristics (perfusion versus metabolism) showed close agreement concerning measurements of left ventricular volumes, contractile function and myocardial mass by using a model-based analysis.