Gated myocardial perfusion tomography for the assessment of left ventricular function and volumes: Comparison with echocardiography

The purpose of this study was to evaluate left ventricular volumes and function by gated SPECT using different tracers and protocols in comparison with quantitative echocardiography. Gated myocardial perfusion scintigraphy permits simultaneous assessment of left ventricular perfusion, function and volumes. Information is scanty regarding the accuracy of absolute left ventricular volumes measurements by this technique. Methods: We performed gated SPECT and echocardiography within 15 d of each other in 109 consecutive patients (53 men, 56 women; mean age 63 ± 14 y). Gated tomographic data, including left ventricular volumes and ejection fraction, were processed using an automatic algorithm, whereas echocardiography used standard techniques. Results: The correlations between gated tomography and echocardiography with respect to end-diastolic volume, end-systolic volume and left ventricular ejection fraction were good to excellent (all P < 0.001, r values ≥ 0.68), regardless of the use of poststress or rest/redistribution images, ²⁰¹Tl or ^99mTc tracers. End-systolic volume was similar with gated tomography and echocardiography (P = ns), but end-diastolic volume and left ventricular ejection fraction were significantly higher with echocardiography (P≤ 0.05). Conclusion: Quantitative gated tomography, using either ²⁰¹Tl or ^99mTc tracers, has a good correlation with echocardiography for the assessment of left ventricular volumes and ejection fraction. These results support the clinical use of this new technique.