BACKGROUND: The purpose of this study was to evaluate (1) the washout kinetics of 99mTc-labeled tetrofosmin, separately for myocardium with normal and reduced perfusion, and (2) its influence on quantitative analysis in a 1-day stress-rest protocol. METHODS AND RESULTS: Twenty-five patients with angiographically proved coronary artery disease underwent bicycle exercise stress testing with injection of 200 MBq 99mTc-labeled tetrofosmin and first single-photon emission computed tomographic (SPECT) imaging 40 minutes after injection. A second SPECT was acquired 2.3 +/- 0.4 hours after the first one immediately before rest injection of 800 MBq 99mTc-labeled tetrofosmin. The rest (third) SPECT was acquired 15 minutes thereafter. The relative washout fraction per time (WOFt) was calculated assuming linear washout kinetics. Thirty-three regional uptake values per study were calculated, normalized to the perfusion maximum (100%) in either the postexercise SPECT and the rest SPECT, for the latter with and without correction of remaining counts from stress injection. In regions with normal perfusion, WOFt was 11.5% +/- 3.5% per hour. In regions with markedly reduced perfusion (relative uptake < 50%, WOFt was 8.3% +/- 9.9% per hour. The highest variation of the relative uptake values between rest SPECT with and without correction of remaining counts from stress injection was 5.4% +/- 3.5% in regions with stress-induced ischemia. CONCLUSION: To use a 1-day protocol with a stress-rest radioactivity ratio of 1:4 and an interval of more than 2 hours between the examinations, a correction for remaining counts from stress injection seems not to be necessary for the quantitative analysis of rest SPECT.
BACKGROUND: The purpose of this study was to evaluate (1) the washout kinetics of 99mTc-labeled tetrofosmin, separately for myocardium with normal and reduced perfusion, and (2) its influence on quantitative analysis in a 1-day stress-rest protocol. METHODS AND RESULTS: Twenty-five patients with angiographically proved coronary artery disease underwent bicycle exercise stress testing with injection of 200 MBq 99mTc-labeled tetrofosmin and first single-photon emission computed tomographic (SPECT) imaging 40 minutes after injection. A second SPECT was acquired 2.3 +/- 0.4 hours after the first one immediately before rest injection of 800 MBq 99mTc-labeled tetrofosmin. The rest (third) SPECT was acquired 15 minutes thereafter. The relative washout fraction per time (WOFt) was calculated assuming linear washout kinetics. Thirty-three regional uptake values per study were calculated, normalized to the perfusion maximum (100%) in either the postexercise SPECT and the rest SPECT, for the latter with and without correction of remaining counts from stress injection. In regions with normal perfusion, WOFt was 11.5% +/- 3.5% per hour. In regions with markedly reduced perfusion (relative uptake < 50%, WOFt was 8.3% +/- 9.9% per hour. The highest variation of the relative uptake values between rest SPECT with and without correction of remaining counts from stress injection was 5.4% +/- 3.5% in regions with stress-induced ischemia. CONCLUSION: To use a 1-day protocol with a stress-rest radioactivity ratio of 1:4 and an interval of more than 2 hours between the examinations, a correction for remaining counts from stress injection seems not to be necessary for the quantitative analysis of rest SPECT.
Authors: C Laubenbacher; J Rothley; J Sitomer; R Beanlands; S Sawada; R Sutor; D Muller; M Schwaiger Journal: J Nucl Med Date: 1993-06 Impact factor: 10.057
Authors: Simona Ben-Haim; Krzysztof Kacperski; Sharon Hain; Dean Van Gramberg; Brian F Hutton; Kjell Erlandsson; Tali Sharir; Nathaniel Roth; Wendy A Waddington; Daniel S Berman; Peter J Ell Journal: Eur J Nucl Med Mol Imaging Date: 2010-04-11 Impact factor: 9.236