Weber Syndrome

The diffusion-weighted image above shows an area of high signal consistent with an acute brainstem infarct.
Weber syndrome is a midbrain stroke syndrome involving the fascicles of the oculomotor nerve leading to an ipsilateral CN III palsy and contralateral hemiplegia or hemiparesis. On imaging alone it is difficult to distinguish Weber from Benedikt syndrome, unless clear involvement of the red nucleus can be identified (seen in the latter).
For FLAIR image of the same patient, please visit Radiopaedia.org here.
References
University of Florida
Neuroanatomy and Pathology on the Internet
Credit: Dr Frank Gaillard
http://www.radpod.org