Ischaemia, blood flow through brain

Topography of focal cerebral ischaemia following obstruction of major cerebral artery. Illustrated using colour-coded blood flow images and double label autoradiography in a model of endothelin-induced experimental stroke. Highest to lowest flows are white, red, yellow to green; v low blue or purple; no or almost no flow black. Credit: Dr I M Macrae/WellcomeTrust Photo Library