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

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 multi-gated 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 I 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% Cl -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.