What is cerebral angiography used for, and how is it performed?
Cerebral angiography shows the arteries of the brain using a catheter and contrast dye. Learn why it is recommended, what the steps involve, its risks, and what to ask beforehand.
By Dr. Martin Roberto Casas MartínezSep 27, 20266 min read
In this article
- What is cerebral angiography?
- What is cerebral angiography used for?
- How is the test performed, step by step?
- What are the risks, and what should I tell the team beforehand?
- Is diagnostic angiography the same as endovascular treatment?
- Frequently asked questions
- What should I ask before angiography?
- References
Summary: Cerebral angiography provides detailed images of the arteries and veins in the brain and can confirm or rule out abnormalities such as aneurysms or vascular malformations. It is performed using a catheter (a thin, flexible tube) inserted through an artery in the groin or wrist. Contrast dye is injected, and X-ray images are taken. It is an invasive test that a specialist recommends when the information could change a decision.
When an MRI or CT scan shows something in the blood vessels of the brain, a catheter-based test is sometimes the next step. Knowing what cerebral angiography is for and how it is performed can help reduce uncertainty before your consultation.
What is cerebral angiography?
This is a minimally invasive imaging test in which a catheter is guided through the arteries to the neck and brain. Contrast dye is injected, and X-ray images are taken to show the blood vessels clearly.
The usual technique is digital subtraction angiography (DSA): a computer “subtracts” the skull bones so that only the blood vessels are visible. It is also called a cerebral angiogram or diagnostic angiography. It differs from CT angiography and MR angiography, which produce images of the blood vessels without a catheter.
What is cerebral angiography used for?
It is used to detect, confirm, and characterize abnormalities in the blood vessels of the brain—aneurysms, arteriovenous malformations, narrowing, tears in the arterial wall, or inflammation of the blood vessels—and to plan treatment when other tests have not provided the necessary information.
An aneurysm is a bulging area in the wall of an artery; an arteriovenous malformation (AVM) is an abnormal connection between arteries and veins. In both cases, angiography shows the shape and size of the lesion and the arteries that supply it—details that help guide the decision to monitor or treat it.
The IMSS quick reference guide on unruptured cerebral aneurysm (2011) considers it the test of choice for diagnosing aneurysms in this context and notes that, because it is invasive, it should be recommended based on clinical judgment.
How is the test performed, step by step?
The test is performed in an interventional radiology suite. An intravenous line is placed, the puncture site is numbed, and the catheter is guided under X-ray to the arteries in the neck. Contrast dye is injected, images are taken, and the access site is closed.
- •Preparation: An intravenous line is placed, and heart rate and blood pressure are monitored; in some cases, an electrocardiogram is also taken.
- •Access: Local anesthesia is used in the groin or wrist. Some people are also given sedation, and children usually receive general anesthesia.
- •Imaging: Using fluoroscopy (real-time X-rays), the catheter is guided to the arteries in the neck. Series of images are taken after contrast dye is injected.
- •Closure and observation: The catheter is removed, and the puncture site is compressed or closed with a closure device. You will then rest and be monitored for a period before discharge.
The test is led by a physician who specializes in interventional neuroradiology or endovascular therapy, with support from nursing staff and radiologic technologists and, if general anesthesia is used, an anesthesiologist.
What are the risks, and what should I tell the team beforehand?
The main risks are an allergic reaction to iodine-based contrast dye, injury to or bleeding from the access vessel, effects on kidney function from the contrast dye, and, rarely, a stroke. The specialist will explain these risks before you decide.
The care team reduces these risks through preparation and monitoring, but cannot eliminate them completely. Before the test, tell the team if you have allergies (especially to iodine-based contrast dye), kidney disease, or diabetes; if you take anticoagulants or antiplatelet medications (medicines that reduce clot formation); or if you might be pregnant.
Do not stop or start any medication on your own. Preparation instructions are tailored to each person and provided by the care team.
Is diagnostic angiography the same as endovascular treatment?
No. Diagnostic angiography only obtains images. Endovascular treatment—such as embolization of an aneurysm or AVM—is a separate procedure that uses the same catheter access route but is intended to treat the lesion.
In some cases, both are performed in the same session if the images confirm that treatment is indicated and this was agreed on beforehand. In other cases, angiography is a preliminary step to decide whether to monitor, operate, or treat the lesion from inside the artery. Ask which scenario applies to your case: you are part of that decision.
Frequently asked questions
Does cerebral angiography hurt?
It usually causes little discomfort. Local anesthesia is given at the puncture site, so you may feel a pinch and some pressure. When the contrast dye is injected, a brief feeling of warmth in the face or head is common and goes away within seconds.
What symptoms after the test mean I should call 911?
Sudden weakness or numbness in the face, an arm, or a leg; difficulty speaking or understanding; sudden vision problems; confusion; or bleeding and increasing swelling at the puncture site. If any of these occur, call 911 without waiting.
How long will I be monitored after angiography?
It depends on the access site and closure method. After access through the groin, you are usually instructed to keep your leg straight and rest for a few hours before discharge. The care team will tell you the exact time and when you can resume your activities.
What should I ask before angiography?
If you have sudden neurological symptoms—weakness on one side of the body, difficulty speaking, or a sudden, severe headache—call 911 first. If your test is already scheduled, these questions can help during your pre-test consultation:
- •What information is the angiography looking for in my case, and what might change based on the results?
- •Where will the access site be, what type of anesthesia will I receive, and how long will I be monitored?
- •Will the angiography and treatment be performed in the same session or at different times?
For non-urgent questions or to request an individual assessment, you can contact the office.
Informational notice: This content is for informational purposes and does not replace a medical consultation or constitute a diagnosis.
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