FIG 3. Sequential changes in the asymmetry index (AI). In the hyperperfusion group (A), the pretreatment index of 70.2% ± 25.2 increases to 116.0% ± 4.5 immediately after carotid stent placement and then decreases to 105.3% ± 4.1 7 days after the procedure (Asterisk indicates P < .01.) The index did not significantly change in the nonhyperperfusion group (B).