Evaluation of right ventricular function by NuSMUGA software: gated blood-pool SPECT vs. first-pass radionuclide angiography

Background: In comparison with planar imaging gated blood-pool single photon emission computed tomography (GBPS) has the advantage of separating left and right ventricle. The purpose of this investigation was to evaluate the right ventricular ejection fraction (RVEF) calculations by GBPS software (‘NuSMUGA™’, Northwestern University, Chicago, IL) in comparison to first-pass radionuclide angiography (FPRNA). Methods: In 22 consecutive patients FPRNA and GBPS acquisition was performed. GBPS RVEF calculations were manually and automatically performed, using all gated short-axis-slices of the right ventricle. Results: Automatic RVEF assessed by GBPS did not correlate with conventional FPRNA (r = 0.40, p = 0.065). Mean FPRNA RVEF was 55 ± 10% and mean GBPS automatic RVEF was 32 ± 8%. Also manual GBPS RVEF did not correlate with conventional FPRNA (r = 0.41, p = 0.055). Mean RVEF measurement by manual GBPS was 33 ± 8%. Manual GBPS RVEF values correlated well with automatically determined GBPS RVEF values (r = 0.96, p < 0.0001). Conclusion: Automatic and manual values RVEF values assessed by GBPS did not correlate with conventional FPRNA values. FPRNA and GBPS calculations cannot be considered to be equivalent. Therefore the NuSMUGA program cannot be used to calculate RVEF.