Figure 5. Dural tail tissue adjacent to meningioma. Lower portion of the photomicrograph (original magnification, x250; hematoxylin-eosin [H-E] stain) shows normal dura mater that is largely collagen. The upper region shows reactive changes characterized by vascular congestion and loosening of the connective tissue. Slow flow within these vessels and accumulation of edema in the dura mater allow enhancement to be visualized on gadolinium-enhanced T1-weighted MR images.