SCALE PWI: A Pulse Sequence for Quantitative Cerebral Perfusion Imaging

INTRODUCTION Quantitative cerebral perfusion is a fundamental physiologic parameter that reflects the severity and progression of a broad range of pathologies including: cancer, stroke, Alzheimer’s Disease, and cerebrovascular occlusive disease. The “Bookend” technique [1,2] allows quantification of cerebral blood flow (CBF) and cerebral blood volume (CBV) with dynamic susceptibility contrast (DSC) MRI and fast T1 measurements before and after DSC. This technique has been proven to be reproducible, reliable and accurate [3]. The current implementation consists of 3 sets of MRI scans performed sequentially requiring a cumulative scan time of 5 minutes. A simplified scan protocol and automatic image processing would enable not only a broader dissemination of this technology but also its utilization in emergency settings such as acute stroke to obtain immediate and accurate diagnosis. Our goal was to come up with a “single” (push-button) MRI pulse sequence that: (1) produces quantitative images of cerebral perfusion without the need for additional “Bookend” scans, (2) eliminates the need of special technologist training, (3) is less prone to motion artifacts, and (4) produces quantitative images of cerebral perfusion without the need for offline post-processing.