Detection and Treatment Guide Updated 2017 Detection-and-Treatment-2017 - Page 12

DIAGNOSIS When a ruptured aneurysm is suspected, a head CT (computerized tomography) scan is performed. This is a painless, non-invasive X-ray exam. A CT scan will show if there has been bleeding in the brain. However, a basic CT scan does not usually show the cause of the bleeding. Using a technique called computerized tomography angiography (CTA), in which a contrast dye is injected into the bloodstream, the brain’s blood vessels are highlighted and aneurysms can be seen using special imaging techniques. Sometimes an angiogram is needed to provide a better view of the aneurysm and blood vessels. An angiogram may be done on an emergency basis after a subarachnoid hemorrhage is detected. For someone with an unruptured aneurysm, the angiogram is often performed as an outpatient procedure in an angiography suite of a hospital. During an angiogram, an area of the groin is numbed and the doctor inserts a catheter into an artery in the groin. The catheter is then advanced to the appropriate area, and a contrast dye is injected through it. The dye highlights the arteries, and X-ray images are taken. Sometimes magnetic resonance imaging (MRI) or magnetic resonance angiography (MRA) are used to screen patients for aneurysms. MRI and MRA, which use computer-generated radio waves and a powerful magnetic field, do not expose the patient to any ionizing radiation (X-rays). CTA, MRA, or an angiogram may also be used to diagnose unruptured aneurysms. 11