During the last years, new MR imaging methods have become available, that are able to detect cerebral ischaemia at a very early stage of the pathological process. Diffusion MR imaging provides information about the disturbances of cellular water homeostasis, thus detecting on of the first elements of the patho-physiological cascade leading to ischaemic injury. Perfusion MR imaging represents a measurement of blood delivery to tissues. It is based on the use of the Blood Oxygen Level Dependant (BOLD) technique, demonstrating the differences between the paramagnetic deoxyhemoglobin or diamagnetic oxyhemoglobin and the surrounding tissues. Diffusion / Perfusion MR imaging allows non-invasive and rapid evaluation of any tissue injury or disturbance of blood flow as early as 105 minutes following ischaemia and can be repeated at short intervals without the hazards of irradiation or other unwanted side effects