TY - JOUR T1 - Myocardial Tracking, A New Method to Calculate Ejection Fraction with Gated SPECT: Validation with <sup>201</sup>Tl Versus Planar Angiography JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 845 LP - 852 VL - 42 IS - 6 AU - Emmanuel Itti AU - Jean Rosso AU - Hatem Hammami AU - Serge Benayoun AU - Jean-Philippe Thirion AU - Michel Meignan Y1 - 2001/06/01 UR - http://jnm.snmjournals.org/content/42/6/845.abstract N2 - Left ventricular ejection fraction (LVEF) and viability are essential variables for the prognosis of myocardial infarction and can be measured simultaneously by 201Tl gated SPECT; however, most algorithms tend to underestimate LVEF. This study aimed to evaluate a new myocardial tracking algorithm, MyoTrack (MTK), for automatic LVEF calculation. Methods: A rest/redistribution (20 min/4 h) 201Tl gated SPECT protocol followed immediately by a 99mTc equilibrium radionuclide angiography (ERNA) was performed in 75 patients with history of myocardial infarction. Quality of myocardial uptake was evaluated from count statistics and automatic quantification of defect sizes and severities (CardioMatch). LVEFs were calculated both with Germano’s quantitative gated SPECT (QGS) algorithm and with MTK. Briefly, the originality of this algorithm resides in the unique end-diastole segmentation, matching to a template and motion field tracking throughout the cardiac cycle. Results: ERNA LVEF averaged 33% ± 14%. QGS significantly underestimated this value at 20 min (30% ± 13%, P &lt; 0.001) and at 4 h (30% ± 13%, P &lt; 0.0001). By contrast, MTK did not miscalculate LVEF at 20 min (34% ± 14%, probability value was not significant) though a similar underestimation occurred at 4 h (31% ± 13%, P &lt; 0.02). Individual differences between early and late gated SPECT values and differences between gated SPECT and ERNA values did not correlate with the extension of perfusion defects, count statistics, or heart rate. Conclusion: The MTK algorithm calculates LVEF on early/high-count images more accurately than ERNA, even in patients with severe perfusion defects, but tends to underestimate LVEF on delayed/low-contrast images, as other algorithms do. ER -