Diagnosis and Screening
Through imaging screening techniques, individuals at high risk of harboring a brain aneurysm can be identified easily with non-invasive imaging tests. Some risk factors for developing brain aneurysms include cigarette use, chronic hypertension and history of cerebral aneurysms in closely related family members. An aneurysm is often diagnosed using a variety of imaging equipment. Some methods include CT Scan, CTA(computerized tomography angiography) - In this procedure, a contrast dye is injected into the bloodstream prior to CT scanning. This process produces detailed images of blood flow in the brain’s arteries., MRIShort for magnetic resonance imaging. MRI is a painless, non-invasive procedure that uses radio waves and a powerful magnetic field to produce detailed images of the brain and other parts of the body. and MRAShort for magnetic resonance angiography. MRA is a painless, non-invasive procedure that uses radio waves and a powerful magnetic field to produce detailed images of blood vessels. Sometimes an injected contrast dye is used..
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 angiogramThe diagnostic radiology study performed to search for an aneurysm or vascular malformation. The radiologist passes a catheter up from an artery in the groin to the arteries in the neck; he or she then injects dye into the carotid and vertebral arteries while multiple x-rays are taken of the arteries in the brain. 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 catheterA flexible tube for insertion into a vessel, body cavity, or duct; used for an angiogram of the brain arteries and in the endovascular treatment of brain aneurysms to provide access to the aneurysm site. into an arteryA thick-walled blood vessel carrying blood flow from the heart to any organ of the body, including the brain. 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.
Screening: Familial Aneurysms
In most cases, brain aneurysms are not hereditary, and there is generally only a single case in a family. Occasionally, however, an individual with a brain aneurysm will have other family members who are affected. When two or more first-degree relatives (parent, child, or sibling) have proven aneurysms, these are called “familial aneurysms.”
Individuals in these families may be at higher risk of developing aneurysms than the general population. Therefore aneurysm screening with an imaging study of the brain arteries is usually recommended, particularly for first-degree relatives.
If an aneurysm is found, the specialist will work with you to determine if the aneurysm should be treated and, if so, what type of treatment to have. If no aneurysm is detected, a repeat screening may be performed in the future.
Data from a large study of familial aneurysms (the Familial Intracranial Aneurysm Study) indicate that there is a 20 percent incidence of aneurysms in first-degree relatives of patients with a familial aneurysm. Family members most likely to have aneurysms were women or individuals who had a history of smoking and/or high blood pressure.