FIG 2. Diffuse astrocytoma. Axial enhanced T2-weighted image shows a left frontal nonenhancing lesion (A). rCBV map shows an obviously reduced rCBV of 0.72, which is consistent with biopsy-proved diffuse astrocytoma (WHO grade II). Immunohistochemical staining (400x) with the monoclonal antibody against VEGF is negative (C).