Cerebral Angiography
Cerebral angiography is a diagnostic method that provides detailed images of the blood vessels inside the skull, combining the use of X-rays with the injection of a contrast material through a catheter that is guided to the brain.
General Description
Cerebral angiography is a procedure used to obtain precise and detailed images of intracranial blood vessels. This is achieved by injecting a contrast material through a catheter (a thin, flexible tube) and capturing images using an X-ray machine.
Additionally, cerebral angiography can be used to perform certain treatments in conjunction with the examination, as the catheter can incorporate the necessary instruments for such procedures.
When Is It Indicated?
A cerebral arteriography allows for the detection and characterization of any abnormalities in the blood vessels of the brain, including:
- Aneurysms.
- Cerebral hemorrhages.
- Arterial narrowing due to the buildup of atherosclerotic plaque.
- Arteriovenous malformations, such as clusters of dilated blood vessels.
- Inflammation of blood vessels (vasculitis).
- Cysts or tumors.
- Arterial dissections.
- Blood clots.
- Strokes.
Therefore, cerebral angiography may be indicated if the patient experiences symptoms such as:
- Severe headaches.
- Dizziness.
- Double or blurred vision.
- Numbness or weakness.
- Seizures.
- Speech difficulties.
- Loss of coordination or balance.
Furthermore, during cerebral angiography, specific procedures can be performed to treat certain disorders without the need for surgery, such as:
- Placement of a stent to widen narrowed arteries.
- Aneurysm repair through embolization.
- Administration of medication to dissolve a clot.
- Clot removal via aspiration.
How Is It Performed?
To perform cerebral angiography, a catheter is inserted into an artery through a small incision, usually in the groin or arm. The catheter is guided to the brain using X-ray imaging as a guide. Once in place, an iodine-based contrast material is injected through the catheter to visualize the blood vessels, which, having the same density as surrounding soft tissues, are not visible on a conventional X-ray. Several X-ray images of the brain’s vascular system (cerebral angiograms) are then taken.
In some cases, images are digitally processed to remove overlapping skull bone, which may interfere with the visibility of the blood vessels. This procedure is known as intra-arterial digital subtraction angiography (IADSA).
Additionally, a non-invasive cerebral angiography can be performed without catheters, using magnetic resonance imaging and the intravenous injection of contrast material (in this case, gadolinium). However, catheter-based cerebral angiography typically provides more precise images.
Risks
Although it is a minimally invasive test, cerebral catheterization is not without risks, though complications occur in only a small number of cases. These include allergic reactions to the contrast material, kidney damage due to the contrast (especially in individuals with diabetes or kidney disease), bleeding at the catheter insertion site, infection of the incision, clot formation around the catheter tip, arterial injuries caused by the catheter’s movement, and strokeStrokeStroke if blood flow is blocked by a clot or dislodged arterial plaque.
Additionally, X-rays are a form of radiation, which is associated with the risk of developing cancer or other health issues. However, given the low radiation dose used, the benefits of performing the test outweigh the potential risk.
What to Expect from a Cerebral Angiography
After removing their clothing and metallic objects, the patient wears the provided gown and lies down on the examination table in the radiology room, where their head is immobilized using a strap or foam support. Once positioned, adhesive electrode patches are applied to monitor blood pressure and heart rate throughout the procedure. A sedative may be administered to keep the patient relaxed.
The insertion site of the catheter is disinfected and shaved if necessary. Before making the incision, a local anesthetic is injected to prevent pain during the procedure (some patients may require general anesthesia). During catheter insertion, pressure may be felt, and as the contrast material moves through the bloodstream, a brief sensation of warmth is commonly experienced.
The entire procedure can take between one and three hours, depending on whether additional treatments are performed along with the examination. Once the test is completed, the catheter is removed, and pressure is applied to the incision for several minutes to prevent bleeding and promote healing. Additionally, if the catheter was inserted through the groin, the patient must remain at rest and keep their leg still for several hours to allow the incision to close (hospitalization overnight may be necessary). It is also recommended to drink plenty of fluids to accelerate the elimination of the contrast material through urine.
Specialties That Request Cerebral Angiography
Cerebral angiography is requested in neurology and vascular surgery consultations.
How to prepare
It is common to conduct a blood test before performing cerebral angiography to assess kidney function and blood clotting. Patients are also typically required to fast completely for six to eight hours before the procedure. Additionally, it is advisable to avoid bringing any objects, as metal is visible on X-ray images and may interfere with the diagnosis.
Moreover, the patient must sign a consent form and inform the specialist in the following cases:
- Anticoagulant treatment: Must be suspended or adjusted a few days before the test to minimize the risk of bleeding.
- Diabetes or kidney function problems: The use of contrast material may be reconsidered.
- History of iodine allergy: Corticosteroids or antihistamines may be administered before the test.
- Pregnancy: A fetus is highly sensitive to radiation, so a lead apron should be used over the abdomen for protection.
