“…In this issue, Fan et al 5 report the use of multidelay arterial spin labeling (ASL) perfusion MRI at 3 T to predict radiographic cerebral hyperperfusion following carotid endarterectomy. In 79 patients with moderate‐to‐severe unilateral carotid stenosis who underwent multidelay ASL perfusion imaging before and after carotid endarterectomy, the authors found that multidelay ASL MRI was able to detect radiographic cerebral hyperperfusion, defined as an increase in cerebral blood flow (CBF) of more than 100% compared with baseline preoperative values.…”