Cerebral arteriovenous malformation.
A. A T1-weighted MR image of a 14-year-old child with recent onset headaches shows a superficial "mass" (arrow) composed of multiple flow voids. The lesion has a triangular shape, with the peripheral aspect wider than the central aspect. B. A sagittal T1-weighted image demonstrates hyperintense blood products (arrow) at the inferior-lateral margin of the lesion. C. The nidus of the malformation enhances intensely with intravenous gadolinium. D, E. Anterior and lateral MRA images confirm that the nidus consists of a tangle of vessels with arterial flow (arrow). The predominant feeding arteries arise from the right middle cerebral and posterior cerebral arteries. There is also supply from the right pericallosal artery.