Assessment of left ventricular volumes and ejection fraction using ultra-low-dose thallium-201 SPECT on a CZT camera: a comparison with magnetic resonance imaging

Background Cadmium-Zinc-Telluride (CZT) technology allows use of low activities of radiopharmaceuticals. The aim was to verify the values of left ventricular volume parameters, obtained via ultra-low-dose thallium Single Photon Emission Computed Tomography (SPECT) using a CZT camera. Methods and Results Forty-five patients referred for an assessment of myocardial perfusion or viability imaging were examined using CZT-SPECT and 1.5 T magnetic resonance (MRI) scanner. The ultra-low-dose protocol with 0.5 Mbq 201-Tl per kg of body weight was used. The values of end-systolic (ESV) and end-diastolic volumes (EDV), left ventricular ejection fraction (EF) and myocardial mass (MM) were assessed using both techniques. A very good correlation was found between the EF, ESV, and EDV values assessed with CZT-SPECT and cardiac magnetic resonance MRI; the Pearson coefficients were 0.86, 0.95, and 0.91, respectively. A moderate correlation was found for myocardial mass, r = 0.57. Compared to MRI, SPECT systematically overestimated ESV and MM, while it underestimates the EF, with P ≤ .001 in all cases. There was no difference in EDV estimation. Conclusions Left ventricular volumes and ejection fraction assessed via ultra-low-dose CZT-SPECT showed very good correlation with the values obtained by MRI. A moderate correlation was found for myocardial mass.