Use of the cavity-to-myocardial count ratio with Tc-99m sestamibi myocardial perfusion SPECT to predict reduced left ventricular function

In patients with left ventricular dysfunction, the left ventricular cavity appears abnormally photopenic on SPECT images, both with T1-201 and Tc-99m sestamibi showed a linear correlation between the cavity-to-myocardial count ratio (C/M ratio) and left ventricular ejection fraction (LVEF) with T1-201 SPECT. Using an exercise ratio of 0.4 as the lower limit of normal, they could predict a reduced LVEF with a sensitivity of 83% and specificity of 78%. The purpose of our study was to ascertain whether the C/M ratio could also be used as an indicator of LVEF when using Tc-99m sestamibi as imaging agent.