The most reliable test to detect a cerebral aneurysm is called a Cerebral Angiogram. This diagnostic test provides images of the blood vessels in the brain or head. A special dye (contrast) is injected into the arteries of the head or brain and the patient is studied through X-ray. An expert physician studies images of the brain to determine if the brain's blood vessels are normal or need intervention. This study of the brain helps diagnose such conditions as a blood clot, fatty plaque that increases a patient’s risk for stroke, cerebral aneurysm or other vascular malformations.