Gated blood-pool SPECT automated versus manual left ventricular function calculations

Comparison of totally automated and manual processing for calculation of left ventricular volumes and ejection fraction using gated myocardial perfusion SPECT

ated single-photon emission computed tomography (SPECT) allows for the assessment of myocardial left ventricular ejection fraction and left ventricular volumes. There is conflicting data regarding the difference between automated and manual processing of gated myocardial SPECT images. The purpose of this retrospective “cross-sectional study is to compare the degree of variability between automated and manual processing of Quantitative Gated SPECT algorithms for assessing left ventricular volumes and ejection percent”. Study was carried out in the Nuclear Medicine department “at the Security Forces Hospital, Riyadh, Saudi Arabia, and comprised of 96 participants who “underwent” both stress and “rest gated” myocardial perfusion “imaging” (MPI) from February to May 2021. Data were analyzed “using SPSS for Windows (version 22; IBM Corp., Armonk, NY, USA). The mean of EF, ESV, and EDV on stress test using the automatic technique were 62.46 ± 14.62%, 45.00 ± 37.10 ml, and 107.01 ± 43.70 ml, respectively while using the manual technique were 57.21±14.80%, 44.35±35.93 ml, and 93.26±39.14 ml, respectively. The mean of EF, ESV, and EDV on rest test using the automatic technique were 62.85± 15.47%, 43.44± 36.35 ml, and 104.27±42.51 ml, respectively while using the manual technique were 57.74±15.33%, 43.30±36.42 ml, and 91.72±41.50 ml, respectively. For LVEF and EDV, the difference between automated and manual techniques is statistically significant (p<0.05). However, no “statistically significant difference” exists between automated and manual ESV techniques (p>0.05). Discrepancies were observed that exist by using the fully automated and manual technique for determining LVEF and Left ventricular volumes by gated MPI.

Comparison of radionuclide ventriculography using SPECT and planar techniques in different cardiac conditions

PURPOSE

Accurate assessment of ventricular function is required to optimize therapeutic management of cardiac diseases. The aim of this study was to correlate planar equilibrium multigated acquisition (MUGA) with tomographic ventriculography (SPECT) in patients with diverse volumes and wall motion abnormalities.

METHODS

Eighty-three studies in 80 patients (56+/-14 years; 56% women) were classified according to ventricular dilation, wall motion abnormalities and systolic dysfunction. Left and right ventricular ejection fraction (LVEF and RVEF) and end-diastolic and end-systolic left ventricular volumes (EDV and ESV) were obtained using a commercial QBS program for SPECT. On planar acquisition, LVEF and RVEF were obtained using standard techniques and volumes were determined using the count-based method, without blood sampling.

RESULTS

A. Total group: With the planar method, LVEF was 44+/-17%, RVEF 42+/-13%, left EDV 147+/-97 ml (range 31-487 ml) and left ESV 93+/-85 ml (range 15-423 ml); with SPECT the corresponding values were 40+/-20%, 49+/-16%,131+/-95 ml and 91+/-89 ml, respectively (p=NS for all but RVEF). Linear correlation was 0.845 for LVEF, 0.688 for RVEF, 0.927 for left EDV and 0.94 for left ESV, with good intra-class correlation. B. Subgroups: Global and intra-class correlations between planar imaging and SPECT were high for volumes, RVEF and LVEF in all subgroups, except in patients with normal wall motion and function, who showed smaller volumes with SPECT. The group with diffuse wall motion abnormalities had a lower EDV on SPECT. In the abnormal left ventricle, RVEF was higher with SPECT.

CONCLUSION

Good correlation and agreement exist between SPECT and planar MUGA with respect to LVEF and left ventricular volumes. SPECT is useful in patients with functional abnormalities, but less reliable in those with normal small cavities. A combined technique is still necessary, and RVEF should be interpreted cautiously.

Agreement between four available algorithms to evaluate global systolic left and right ventricular function from tomographic radionuclide ventriculography and comparison with planar imaging

BACKGROUND AND AIM

Left and right ventricular ejection fractions (LVEF and RVEF) and end-diastolic and end-systolic volumes (LVEDV, RVEDV, LVESV and RVESV) can be calculated from tomographic radionuclide ventriculography (TRV). The aim of this study was to validate and compare these parameters obtained using four different TRV software programs (QBS, QUBE, 4D-MSPECT and BP-SPECT).

METHODS

LVEF obtained from planar radionuclide ventriculography (PRV) was compared with LVEF obtained from TRV using the four different software programs in 166 patients. Furthermore, ventricular volumes obtained using TRV (QBS, QUBE and 4D-MSPECT) were compared with those obtained using BP-SPECT, the latter being the only method with the validation of ventricular volumes in the literature.

RESULTS

The correlation of LVEF between PRV and TRV was good for all methods: 0.81 for QBS, 0.79 for QUBE, 0.71 for 4D-MSPECT and 0.79 for BP-SPECT. The mean differences+/-standard deviation (SD) were 3.16+/-9.88, 10.72+/-10.92, 3.43+/-11.79 and 2.91+/-10.39, respectively. The correlation of RVEF between BP-SPECT and QUBE and QBS was poor: 0.33 and 0.38, respectively. LV volumes calculated using QBS, QUBE and 4D-MSPECT correlated well with those obtained using BP-SPECT (0.98, 0.90 and 0.98, respectively), with mean differences+/-SD of 7.31+/-42.94, -22.09+/-36.07 and -40.55+/-39.36, respectively. RV volumes showed poorer correlation between QBS and BP-SPECT and between QUBE and BP-SPECT (0.82 and 0.57, respectively).

CONCLUSION

LVEF calculated using TRV correlates well with that calculated using PRV, but is not interchangeable with the value obtained using PRV. Volume calculations (for left and right ventricle) and RVEF require further validation before they can be used in clinical practice.