FIGURE 6. Ultrasonic coronary blood flow and t_1/2 of ^99mTcN-NOET intrinsic myocardial washout from canine myocardium at rest (control) and during vasodilator stress (hyperemia). t_1/2 values were determined by applying exponential fit (y = a₀ x exp[-x/a₁]) to individual ^99mTcN-NOET intrinsic myocardial washout curves. Data are mean ± SEM of 6 experiments. *P < 0.05 vs. control.