Accuracy of the automated assessment of left ventricular function with gated perfusion SPECT in the presence of perfusion defects and left ventricular dysfunction: Correlation with equilibrium radionuclide ventriculography and echocardiography

Background. Gated single photon emission computed tomography (SPECT) with a utomated methods allows the quantitative assessment of left ventricular fun ction and perfusion; however, its accuracy must be defined for patients wit h large earlier infarctions and severe rest perfusion defects, in whom the estimation of endocardial and epicardial borders might be more difficult, e ven with automated edge-detection techniques. Methods and Results, We prospectively compared the automated measurements o f left ventricular ejection fraction (LVEF) and volumes from rest-injected gated Technetium 99m (Tc-99m) perfusion SPECT with equilibrium radionuclide angiocardiography (ERNA) in 62 patients and the assessment of regional fun ction,vith echocardiography in 22 patients. Forty-six patients had an earli er myocardial infarction (mean defect size, 34% of left ventricle; SD, 12.7 %; range, 8% to 56%); 27 patients had large defects (greater than or equal to 20% of left ventricle; LVEF range, 8% to 75%), LVEF, as determined with Cedars-Sinai software (quantitative gated SPECT), correlated well with ERNA (r = 0.941; y = 1,003x + 1.15; P < .0001; SE of the estimate = 6.3%; mean difference -1.3% for LVEF) in the entire study population and in the subgro ups of patients with an earlier infarction, severe defects, and large infar ctions (greater than or equal to 20% of the left ventricle), A correlation existed between gated SPECT and ERNA volumes (r = 0.882, y = 1.040x - 14.7, P < .0001 for end-diastolic volume; r = 0.954, y = 1.147x - 13.9, P < .000 1 for end-systolic volumes with the count-ratio technique), but with wider limits of agreement. The exact segmental score agreement between gated SPEC T and echocardiography for regional function was 79.8% (281 of 352, kappa = 0.682), Conclusions, Automated gated SPECT provides an accurate assessment of eject ion fraction and regional function, even in the presence of an earlier myoc ardial infarction with large perfusion defects and significant left ventric ular dysfunction.