Gated planar technetium 99m-labeled sestamibi myocardial perfusion image inversion for quantitative scintigraphic assessment of left ventricular function.

BACKGROUND

Quantitative assessment of left ventricular systolic performance in conjunction with myocardial perfusion scintigraphy would significantly expand the clinical information obtained from these studies.

METHODS AND RESULTS

Left ventricular function was evaluated in 264 patients in whom planar 99mTc-labeled sestamibi myocardial perfusion images were obtained in the best septal left anterior oblique projection. Digital inversion of these perfusion images allows semiautomated evaluation of the left ventricular cavity, with the commonly available edge-detection software designed for equilibrium blood pool imaging. In this study, ejection fractions derived from this technique were compared with those obtained from a myocardial perfusion phantom, first-pass radionuclide angiography, and contrast ventriculography. In vitro validation demonstrated that the myocardial perfusion image inversion ejection fractions correlated linearly with those obtained from a double-chamber phantom (r = 0.999). In vivo, there was good linear correlation between image inversion and first-pass (r = 0.88; image inversion = 0.98 first-pass +0.11), with 95% agreement on the presence or absence of significant left ventricular systolic dysfunction. There was also very good correlation between image inversion and contrast ventriculographic ejection fractions (n = 35; r = 0.85; image inversion = 0.8 contrast +0.05). Intraobserver and interobserver variability of the image inversion ejection fractions was very small (mean difference of 0.4 +/- 0.8 and 2.8 +/- 4.7 units, respectively).

CONCLUSION

Gated 99mTc-labeled sestamibi myocardial perfusion image inversion allows evaluation of the dynamics of the left ventricular chamber changes during the cardiac cycle, providing a method for evaluation of systolic function during myocardial perfusion imaging, with highly reproducible results that correlate well with established techniques.