Electrocardiographic-gated dual-isotope simultaneous acquisition SPECT using18F-FDG and99mTc-sestamibi to assess myocardial viability and function in a single study.

Purpose: Dual-isotope simultaneous acquisition single-photon emission computed tomography (DISA SPECT) with ¹⁸F-fluorodeoxyglucose (FDG) and ^99mTc-sestamibi appears attractive for the detection of viable myocardium because it permits simultaneous assessment of glucose utilisation and perfusion. Another potential benefit of this approach is that the measurement of left ventricular (LV) function may be possible by ECG gating. The aim of this study was to test the hypothesis that both myocardial viability and LV function can be assessed by a single ECG-gated ¹⁸F-FDG/^99mTcsestamibi DISA SPECT study, based on comparison with ¹⁸F-FDG/¹³N-ammonia positron emission tomography (PET) and magnetic resonance imaging (MRI) as reference techniques. Methods: Thirty-three patients with prior myocardial infarction underwent ECG-gated ¹⁸FFDG/ ^99mTc-sestamibi DISA SPECT and ¹⁸F-FDG/¹³Nammonia PET on a single day. Of these, 25 patients also underwent cine-MRI to assess LV function. The LV myocardium was divided into nine regions, and each region was classified as viable or scar using a semiquantitative visual scoring system as well as quantitative analysis. The global and regional LV function measured by gated SPECT was compared with the results of MRI. Results: There was good agreement in respect of viability (90-96%, κ 0.74-0.85) between DISA SPECT and PET by either visual or quantitative analysis. Furthermore, although both global and regional LV function measured by gated SPECT agreed with those by MRI, ^99mTc-sestamibi showed a closer correlation with MRI than did ¹⁸F-FDG. Conclusion: In conclusion, ECG-gated DISA SPECT provides information on myocardial viability, as well as global and regional LV function, similar to that obtained by PET and MRI. [ABSTRACT FROM AUTHOR]