In recent years, a substantial number of imaging studies hav addressed the neuronal processes underlying recovery after stroke. Although difficult to achieve, several longitudinal studies assessed both clinical recovery and imaging patterns over time and give important inside into the plasticity of the stroked brain. This tendency is supported by the fact that it has become possible to depict biological processes at the cellular and molecular level. These new research methods use magnetic resonance imaging (MRI), positron emission tomography (PET), near-infrared optical imaging, scintigraphy, and autoradiography in vivo and in vitro. Of primary interest is the development of methods using MRI and PET with which the different kinds of progress of therapy in acute ischemic stroke can be monitored and graphically displayed. Steps to intervene with secondary biochemical, molecular, or inflammatory disturbances have not been successful so far. Recent activation studies have provided interesting information about the brain's capacity to reorganize after ischemic stroke and in association with practice and learning. The emerging studies of brain plasticity and its modulation by drugs and other therapies indicate potentially useful approaches to the rehabilitation of adults with brain damage, including damage resulting from cerebral ischaemia. Recent advances in state-of-the-art imaging techniques make it possible to visualize physiological parameters such as molecular diffusion, tissue perfusion and cortical activation. These techniques greatly contribute to the early detection and to the understanding of the pathophysiological evolution and recovery from ischemic stroke patients. Numerous theories and hypothesis have been forwarded to explain the neurological recovery seen after an acute ischemic stroke . Functional brain imaging has offered an opportunity to visualize cerebral activation associated with recovery from a stroke. Functiona