Assessment of left ventricular systolic and diastolic function based on the edge detection method with myocardial ECG-gated SPET

The aim of this study was to determine the feasibility of assessing left ventricular systolic ejection and diastolic filling by the edge detection method with ECG-gated single-photon emission tomography (G-SPET) data. Fifty-two patients who had undergone both G-SPET and gated equilibrium blood pool scintigraphy (GBP) within an interval of 2 weeks were enrolled. For G-SPET, 740 MBq of technetium-99m methoxyisobutylisonitrile (MIBI) was injected at rest, and myocardial SPET was performed 60 min later using 360° acquisition and 12 frames per cardiac cycle. In each frame, left ventricular volume was determined with automatic edge detection using a quantitative gated SPET program, and the time-volume curve was fitted by Fourier transform of the first to fourth harmonics. Ejection fraction (EF, %), peak ejection rate (PER, /s), peak filling rate (PFR, /s) and mean filling rate during the first third of diastolic time (1/3FRm, /s) were calculated from the fitted curve. These parameters were also calculated by means of GBP performed with 24 frames per cardiac cycle. Correlation coefficients in respect of EF, PER, PFR and 1/3FRm between G-SPET and GBP were 0.90 (P<0.001), 0.88 (P<0.001), 0.80 (P<0.001) and 0.82 (P<0.001), respectively. The correlations were good for EF, PER and 1/3FRm. Gated SPET dV/dt parameters were slightly lower compared with GBP values owing to the limited number of frames per cardiac cycle. It is concluded that left ventricular ejection and filling rates can be calculated using G-SPET with edge detection software, and in this study these parameters were significantly correlated with those derived using GBP. Diastolic abnormality on gated SPET study should be recognised as a positive finding, and appropriate gated SPET parameters should be further investigated.