FIRST-PASS VENTRICULAR EJECTION FRACTION USING A SINGLE-CRYSTAL NUCLEAR CAMERA

The purpose of the study was to evaluate the reliability of ejection f ractions obtained from first-pass radionuclide ventriculography with a large field-of-view tomographic single-crystal gamma camera. Methods: A SPECT camera had its electronics redesigned to improve counting eff iciency and was equipped with an experimental ultra-high sensitivity c ollimator. Left ventricular ejection fraction (LVEF) was measured in 2 8 patients by 30 degrees RAO first-pass imaging and by ''best septal v iew'' LAO planar equilibrium radionuclide ventriculography on a conven tional small field of view Anger camera. For 28 other patients, first- pass ejection fractions were compared to multicrystal gamma camera val ues. Visual analysis was performed to judge clinical acceptability of first-pass images for identification of wall-motion abnormalities. Res ults: Linear regression analysis of first-pass against equilibrium eje ction fraction demonstrated good correlation (r = 0.92; slope = 0.90; intercept = 3.8; s.e.e. = 6.4%). First-pass ejection fraction values a lso correlated linearly with multicrystal camera values for the left v entricle (r = 0.94; slope = 1.05; intercept = 1.3; s.e.e. = 5.3%). For a subgroup of 19 patients, single-crystal camera right ventricle ejec tion fraction demonstrated good correlation with multicrystal camera v alues (r = 0.82; slope = 1.15; intercept = 1.3; s.e.e. = 6.1%). Intero bserver variability correlated as r = 0.99 for LVEF ejection fraction and r = 0.92 for RVEF. Chi-square analysis of single-crystal first-pas s image visual scores versus those from the gated equilibrium acquisit ions showed close agreement (p < 10(-8)). Conclusions: The evaluated c amera/collimator system measured left and right ventricular ejection f raction accurately. Lung frame correction and dual regions were superi or to paraventricular background correction and a fixed end-diastolic region.