Materials and Methods Patients

Arterial spin labeling (ASL), a noninvasive MR perfusion imaging technique, does not require the administration of potentially toxic exogenous contrast agents.1–3 Mainly used for research, advances in labeling and image readout make ASL easily applicable to routine clinical use. ASL identifies perfu-sion defects and, therefore, aids in identifying areas of penum-bra in patients with acute ischemic stroke (AIS).4–6 This study sought to determine the reliability of ASL in comparison with dynamic susceptibility contrast (DSC) imaging for reperfusion evaluation in patients with AIS