Attenuation corrected gated SPECT for the assessment of left ventricular ejection fraction and volumes

Abstract

Objective: The aim of this study was to evaluate the value of attenuation correction (AC) of Tc-99m tetrofosmin single-photon emission tomography (SPECT) imaging for the assessment of left ventricular ejection fraction (LVEF).

Methods: Attenuation corrected and non-attenuation corrected (NC) resting Tc-99m tetrofosmin SPECT were compared for the assessment of LVEF. Planar multigated radionuclide angiography (MUGA) served as the reference for LVEF assessment. Patients (n = 56) with left ventricular dysfunction who underwent MUGA and rest gated Tc-99m tetrofosmin SPECT within 1 month were included.

Results: The average LVEF on NC gated SPECT was 37.4 +/- 11.8% and on AC SPECT 38.5 +/- 13.4% (P = NS). The absolute mean difference of the LVEF between the MUGA and NC gated SPECT and AC gated SPECT was -0.2% (95% CI -1.7 to 1.3) and -1.3% (95% CI -2.7 to 0.03), respectively (P = NS both vs. MUGA). The correlation between NC gated SPECT and AC gated SPECT versus MUGA measurement was high with a correlation coefficient of 0.89 (P < 0.01) and 0.92 (P < 0.01), respectively. End-diastolic volumes (EDVs) and end-systolic volumes (ESVs) were significantly higher with AC gated SPECT when compared with NC gated SPECT (both P < 0.001).

Conclusions: Profile AC gated Tc-99m tetrofosmin SPECT agrees well with MUGA and NC gated Tc-99m tetrofosmin SPECT for the assessment of LVEF. EDVs and ESVs are significantly higher with AC gated SPECT when compared with NC gated SPECT.