[Importance of correction for background in radionuclide ventriculography (equilibrium technic)].

In evaluating radionuclide ventriculography which includes a background subtraction step, the considerable effect of this step on the calculated ejection fraction ought to be considered. An overestimate of the background activity will result in a falsely high ejection fraction and vice versa. Errors in background subtraction should be realized and eliminated. The background activity ought to be measured in each examination and should not be considered as constant. A simple method of background determination and subtraction is proposed.