If a cerebral aneurysm is suspected, a CT scan or MRI is usually the first step toward diagnosing the cause of the problem.
If an unruptured aneurysm is seen on a CT or MRI scan, or a subarachnoid hemorrhage is found, the physician may perform a diagnostic test known as a cerebral arteriogram (also called cerebral angiogram) to pinpoint the aneurysm's location and clarify potential treatment options. A catheter (thin tube) is inserted into an artery in the leg and guided through the bloodstream to the arteries in the neck that lead to the brain. Dye is injected into the arteries as X-rays are taken. These images provide a map of the arteries. MRI and CT scans that use dye to help highlight blood circulation (MRA and CTA) also can be used to find a brain aneurysm. A cerebral angiogram, however, often provides more definitive information.
