Abstract
Background: The aim of this study was to evaluate the assessment of the left ventricular ejection fraction (LVEF) in patients by gated IQ-SPECT (Siemens Medical System). Methods and Results: 28 patients were examined using gated 99mTc-sestamibi IQ-SPECT. Two different gated reconstruction datasets were cre-ated based on the recommendations of the manufacturer. For each dataset end diastolic volume (EDV), end systolic volume (ESV) and LVEF were calculated using 4DMSPECT. A multigated planar equilibrium radionuclide ventriculography (MUGA) study with 99mTc –labeled red blood cells was used as a reference for the LVEF. The values of the different datasets were tested using the Bland-Altman analysis method. The calculated mean and 95% limits of agreement for the LVEF comparing dataset one and two was -1.1%, and 14%-points to -16%-points, comparing dataset one with MUGA the mean was calculated to -3.1%-points and 14%-points to -20%-points for the 95% limits of agree-ment, and comparing dataset two and MUGA gave a mean of -4.2%, and a 95% limits of agreement of -22%-points to 14%-points. Conclusion: None of the two gated reconstructed datasets analyzed with 4DMSPECT were comparable to LVEF estimated by MUGA with a ten-dency to overestimate LVEF. However large random variations of the EDV, ESV and LVEF between the two gated reconstructed datasets were found. The reconstructed datasets were not interchangeable. Thus, these values should only be used with great caution when evaluating the functional state of the heart.
