Sex-specific criteria for interpretation of thallium-201 myocardial uptake and washout studies.

A study was undertaken to determine the effect of gender on criteria for the quantitative analysis of exercise-redistribution 201Tl myocardial scintigraphy. The studies of 26 normal females and 23 normal males were subjected to bilinear interpolative background subtraction and horizontal profile analysis. Significant sexual differences were found in both regional uptake ratios and washout rates. These differences primarily reflected a proportionately decreased anterior and upper septal uptake in females, and faster washout in females. Faster myocardial 201Tl washout rates in females could not be clearly ascribed to either a physiological or artifactual explanation. It is concluded that since important differences exist between males and females in the detected pattern of 201Tl myocardial uptake and washout, sex-specific criteria may enhance the predictive accuracy of exercise-redistribution 201Tl myocardial scintigraphy.