Imagine the luck of this boy. He had an incidental head injury. No post injury symptoms, but anxious parents said let's do a head CT trauma protocol. CT technician flagged left frontal subarachnoid hemorrhage. I reviewed the images and immediately realized this is an abnormal vessel. Let's just do a venogram. And that revealed this tuft of vessels having arterial feeders from cortical branches of the left middle cerebral artery.