Assessment of Left Ventricular Ejection Fraction by Thallium-201 Myocardial SPECT-CT in Patients with Angina Pectoris: Comparison with 2D Echocardiography

Abstract

Purpose: Left ventricular (LV) ejection fraction (EF) is an important parameter for assessing cardiac systolic function and predicting prognosis in patients with cardiovascular disease. The aim of this study was to evaluate the feasibility of assessing LVEF by Tl-201 hybrid myocardial single-photon emission computed tomography (SPECT)/CT using two attenuation correction methods in patients with angina pectoris. Methods: A total of 339 patients with angina pectoris (62.8 ± 12.9 years, male:female = 206:133) were analyzed. All patients underwent Tl-201 myocardial SPECT/CT and transthoracic two-dimensional (2D) echocardiograph. We compared LVEF assessed by SPECT/CT using two attenuation correction methods: CT-based attenuation correction (CTAC) and non-attenuation correction (non-AC) methods and 2D echocardiography. Results: LVEF assessed by either of the two attenuation correction techniques and 2D echocardiography showed moderate correlation in all patients with angina pectoris (r = 0.487 for CTAC and r = 0.473 for non-AC, p ˂ 0.001). Results were similar in the subgroup of patients with perfusion abnormalities on myocardial SPECT/CT images. Overall diagnostic performances were similar for the CTAC and non-AC methods for evaluating normal and decreased LVEF by myocardial SPECT/CT. Conclusion: LVEF measured by the CTAC method of Tl-201-gated myocardial SPECT/CT was comparable with the conventional non-AC method in patients with angina pectoris and in the subgroup of patients with perfusion abnormality. Tl-201-gated myocardial hybrid SPECT/CT can be a reliable tool in the assessment of LVEF in clinic.