Figure 2. Dura-arachnoid pachymeningeal enhancement in a patient with intracranial hypotension. Sagittal gadolinium-enhanced T1-weighted MR image shows diffuse enhancement of the dura-arachnoid including the falx cerebri. Intracranial hypotension causes not only enhancement but also diffuse thickening of the pachymeninges. This abnormal thickening is especially prominent in the dura mater along the clivus (arrows) and tentorium (arrowheads). (Courtesy of Lazslo Mechtler, MD, Dent Neurological Institute, Buffalo, NY.)