RT Journal Article SR Electronic T1 The Four Ps of Acute Stroke Imaging: Parenchyma, Pipes, Perfusion, and Penumbra JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 599 OP 601 VO 22 IS 4 A1 Rowley, Howard A. YR 2001 UL http://www.ajnr.org/content/22/4/599.abstract AB