LEFT-VENTRICULAR CAVITY-TO-MYOCARDIUM COUNT RATIO IN TECHNETIUM-99M-SESTAMIBI SPECT IN THE DETECTION OF RESTING LEFT-VENTRICULAR DYSFUNCTION

The aim of this study was to assess the value of the cavity-to-myocard ium count ratio (C/M ratio) calculated in resting Tc-99m-sestamibi SPE CT images to identify patients with depressed left ventricular ejectio n fraction (LVEF). Methods: In the 95 patients studied, the C/M ratio was calculated from the midventricular short-axis slice using regions of interest drawn in the center of the cavity and in the most active a rea of the ventricular wall; its value was compared with LVEF measured using two-dimensional echo-cardiography. Results: The C/M ratio corre lated with LVEF (r = 0.6, p < 0.000001) and was significantly lower in patients with abnormal LVEF than those with normal LVEF: 0.026 +/- 0. 028 versus 0.125 +/- 0.093, p < 0.000001. In the entire patient popula tion, a C/M ratio < 0.07 identified the patients with depressed LVEF w ith a 94% sensitivity, 71% specificity and 82% accuracy. Conclusion: T he resting Tc-99m-sestamibi C/M ratio is a useful parameter in identif ying patients with depressed LVEF directly from the SPECT perfusion im ages.