Abstract T P27: Arterial Spin-Labeled Perfusion Imaging to Predict Mismatch in Acute Ischemic Stroke

Abstract

Background and Purpose: We assigned a threshold to arterial spin-labeling (ASL) perfusion-weighted images (PWI) from patients with acute ischemic stroke (AIS) and compared them with dynamic susceptibility contrast (DSC) perfusion images to examine whether mismatch can be determined. Methods: Pseudo-continuous ASL was combined with DSC-PWI in 23 AIS patients. Scans were obtained within 24 hours of symptom onset. PWI volumes were defined by ASL cerebral blood flow- (<15, <20, and <25 mL/100 g/min) and DSC-mean transit time (MTT) thresholds (>10 seconds) that show a strong association with CBF <20 mL/100 g/min in Xenon CT studies. Agreement between the ASL-DWI and MTT-DWI mismatch and the correlation between penumbra salvage and infarct growth, defined as the difference between the baseline PWI- and the baseline DWI lesion, respectively, and the final infarct volume were assessed. Results: The lesion volumes defined by MTT >10 seconds and ASL <20 mL/100 g/min showed an excellent correlation. There were 100% agreement on the mismatch status between MTT >10 seconds and ASL <20 mL/100 g/min. The correlation between infarct growth and penumbra salvage volume was significantly better for PWI lesions defined by ASL <20 mL/100 g/min and MTT >10 seconds. Conclusion: In AIS, PWI lesions based on ASL threshold of <20 mL/100 g/min can provide a reliable estimate of mismatch in correspondence at MTT threshold of >10 seconds.