Figure 8b. Pia-arachnoid leptomeningeal enhancement. (a) Diagram illustrates the enhancement pattern, which follows the pial surface of the brain and fills the subarachnoid spaces of the sulci and cisterns. (b, c) Axial contrast-enhanced CT scan (b) and gadolinium-enhanced T1-weighted MR image (c) in a case of carcinomatous meningitis show pia-arachnoid enhancement along the surface of the brain and extending into the subarachnoid spaces between the cerebellar folia.