[Comparative study of the global left ventricular ejection fraction obtained by ECG gated perfusion MIBI and thallium...

The isotopic LVEF was measured by a planar method with injection of a product visualising the ventricular cavity. Perfusion was assessed by Thallium and sesta MIBI. The investigation of ischaemia and assessment of wall motion in the coronary patient, therefore, requires two isotopic methods. The Cedars Sinai group have developed a programme allowing acquisition of a perfusion tomoscintigraphy in the cardiac cycle after injection of MIBI. This programme automatically detects the endocardial borders and calculates the LVEF. This provides a study of function and perfusion in a single investigation. However, MIBI is not considered by all as a good marker of viability, contrary to Thallium. And the acquisition of Thallium tomography with ECG gating may pose problems because of the low counting statistic. Several authors have therefore studied the possibility of using it for assessing left ventricular function. The authors have then compared LVEF with MIBI and with Thallium in 72 patients. The Thallium LVEF was 33.62% +/- 15.79%; that of MIBI was 32.51% +/- 14.73%. ThalEF = MIBI EF x 1.02 + 0.34 (r = 0.955). The mean of the standard deviation was 1.09. In conclusion, the EF measured by Thallium tomography with ECG gating was closely correlated to that obtained with MIBI. These results suggest that myocardial viability, ischaemia and function may be studied in routine daily practice with a single injection, so improving patient comfort and reducing the costs of the procedures.