Quantification of Left Ventricular Function with Thallium-201 and Technetium-99m-Sestamibi Myocardial Gated SPECT

Myocardial gated SPECT with 99m Tc-sestamibi has been used to quantify left ventricular function. The purpose of this study was to determine if myocardial gated SPECT with 201 Tl was possible and reliable to quantify left ventricular function. Methods: One hundred and four patients referred for a myocardial perfusion study were included. Myocardial gated SPECT acquisition was performed 15 min after the intravenous injection of 111 MBq (3 mCi) 201 Tl and at 1 hr postinjection of 925 MBq (25 mCi) 99m Tc-sestamibi. A commercially available automated myocardial gated SPECT processing software was used. Parameters evaluated were left ventricular ejection fractions (LVEF), end-diastolic volumes (EDV), end-systolic volumes (ESV) and stroke volumes (SV). Results: The correlation between gated SPECT with 201 Tl and gated SPECT with 99m Tc-sestamibi was: r = 0.93 for LVEF, 0.92 for EDV, 0.96 for ESV and 0.68 for SV. Conclusion: Myocardial gated SPECT quantification of left ventricular function with 201 Tl was possible and as reliable as gated SPECT with 99m Tc-sestamibii There was excellent correlation between gated SPECT with 201 Tl and gated SPECT with 99m Tc-sestamibi. In addition to assessment of myocardial perfusion, myocardial function and viability can be quantified in a single gated 201 Tl study.