@inbook{126643, author={David T. Schwartz}, title={Chapter VI-11. Advances in Stroke Imaging—Perfusion CT and MRI, the Ischemic Penumbra}, booktitle={Emergency Radiology: Case Studies}, publisher={The McGraw-Hill Companies}, address={New York, NY}, year={2008}, url={accessemergencymedicine.mhmedical.com/content.aspx?aid=126643} }