Gated blood pool SPECT for measurement of left ventricular volumes and left ventricular ejection fraction: comparison of 8 and 16 frame gated blood pool SPECT

Gated blood pool SPECT (GBPS) is an alternative to planar radionuclide ventriculography (PRNV) and offers potential advantages. The aim of this study was to compare 8 and 16 frame GBPS for the determination of left ventricular ejection fraction(LVEF) and left ventricular volumes (LV) in subjects underwent two consecutive GBPS. Method: About 66 consecutive patients (30 men, 36 women; mean age 62.3 ± 10.4 years) referred for PRNV for evaluation of preoperative cardiac risk stratification (n=40), prechemotherapy cardiac function evaluation (n=18, breast cancer), and congestive heart failure patients (n=8). All patients underwent PRNV of 16 frame and GBPS with both of 8 and 16 frame. Results: The mean LVEF calculated with PRNV (58.3 ± 16.8), showed statistically lower than 8-GBPS (70.6 ± 17.7), and 16-GBPS (69.9 ± 16.8) (PRNV vs. 8-GBPS, p < 0.01; PRNV vs 16-GBPS, p < 0.01; 8-GBPS vs 16-GBPS, p > 0.05). The correlation of LVEFS between 8-GBPS and 16-GBPS showed a correlation coefficient of 0.9194 (p < 0.01, 95% CI=0.8712–0.9500). The mean left ventricular end-diastolic volumes (EDV) calculated with 8-GBPS (83.2 ± 33.5 ml), and 16-GBPS (88.4 ± 36.8 ml) showed no statistical differences (p > 0.05). The mean left ventricular end-systolic volumes (ESV) calculated with 8-GBPS (28.1 ± 31.4 ml), and 16-GBPS (30.5 ± 33 ml) showed also no statistical differences (p > 0.05). Comparison of EDV from 8 and 16-GBPS yielded a correlation coefficient of 0.7430 (p < 0.01, 95% CI=0.6108-0.8349). The correlation between ESV of 8-GBPS and 16-GBPS showed a correlation coefficient of 0.9522 (p < 0.01, 95% CI=0.9228–0.9705). Conclusion: This study demonstrated that the LVEFs of 8-GBPS correlated well with that of 16-GBPS. The LVEF of PRNV was significantly lower than those of 8 and 16-GBPS. Also, left ventricular EDV and ESV of 8-GBPS correlated well with those of 16-GBPS. Also, further studies, involving large lumber patients, should be performed to validate the usefulness of GBPS for the evaluation of left ventricular diastolic function.