Cerebral angiogram

Your doctor has requested that you have a cerebral angiogram. We hope the following information will answer some of the questions you may have about this procedure.

What is a cerebral angiogram?

An angiogram is a procedure where blood vessels are examined closely, by means of x-rays. A special dye called contrast medium is injected into an artery through a fine plastic tube called a catheter and then images are taken immediately afterwards. In your case we will be looking specifically at the head and neck vessels.

Why do I need to have a cerebral angiogram?

The purpose of this procedure is to enhance and increase the information that the doctors may already have from MRI, CT or Ultrasound, in order to have a detailed map of your head and neck circulation.

Who has made this decision?

Your suitability for the treatment will have been made by the doctor in charge of your case and the consultant neuroradiologist (specially trained X-ray doctor) at the hospital. The purpose of the procedure and potential complications will have been explained and will be explained again when you attend for the appointment.

What happens before the procedure?

Prior to the procedure you will have already:

  • Attended the pre assessment clinic or completed a telephone consultation to perform standard checks, for example blood tests, MRSA test and discussion of existing medication.
  • There is no preparation for this procedure; you can continue to eat and drink as normal, unless instructed otherwise.
  • If you are taking any blood thinning tablets which include anti platelets please contact the Imaging department before the appointment using the number on your appointment letter as you may need to consult your GP before undergoing this test.
  • Please make arrangements for someone to collect you from the hospital and take you home by car, as we advise not to use public transport. You are not permitted to drive for 24 hours after the procedure and we would like someone to stay with you at home in the first 24 hours. Please inform the Imaging department if this is not possible, as we will need to identify alternative arrangements.

On the day of the procedure:

  • You will arrive at the Imaging Department (Gate 19) and be accompanied into our day case area.
  • Please bring a list of your regular medications with you.
  • Please inform us if you are allergic to anything.
  • You may take your normal medication unless instructed otherwise.
  • A neuroradiologist will discuss the procedure with you and the benefits and potential risks to you. You will have an opportunity to ask questions about the procedure. If you choose to have the procedure you will need to sign a consent form.
  • You will be asked to change into a hospital gown.
  • Once all the checks have been performed and consent signed, you will be taken to the angiography suite (procedure room). You will be asked to lie down on the X-ray table for the procedure and this may take up to one hour. There will be a small team of nurses, doctors and radiographers with you throughout.
  • The procedure is usually performed with patients awake. A cerebral angiogram can be performed through a blood vessel in the wrist or leg - the neuroradiologist will discuss this with you before the procedure.
  • Monitoring equipment will be attached to you so we can monitor your blood pressure, heart rate and oxygen levels throughout the procedure.
  • The nurse will then clean the area at the top of your leg or wrist with an antiseptic solution and cover you with sterile drapes. The x-ray machine at this point may move around you, but will not touch you.
  • An ultrasound machine will be used to find a suitable blood vessel.
  • The neuroradiologist will then inject local anaesthetic into the area at the top of your leg or wrist, which may briefly sting and then go numb. After this, you may just feel a pushing sensation when a small plastic tube (catheter) is inserted into your artery and the catheter fed through.
  • Once the catheter is maneuvered into the correct positions, contrast medium is injected into different blood vessels and images are then acquired. The injection of the contrast medium, may give you a momentary warm feeling, a strange taste in your mouth and flashing lights behind the eyes. Just before the dye is injected you will be asked to hold your breath and keep still for around 10 seconds. You should avoid moving, swallowing, or blinking. This allows the clearest images possible to be captured.
  • The injections will be repeated until all the necessary images have been obtained.
  • At the end of the procedure the catheter will be removed from your wrist or leg.

What happens after the procedure?

If your procedure is performed through a blood vessel in the wrist

  • An inflatable wrist band will be used to prevent any bleeding.
  • You will need to wear this for 1 - 2 hours but you can sit up and walk around immediately after the procedure.
  • You will then be transferred back to the day case unit where the day case team will monitor you closely until you are ready to go home.
  • If you feel the wrist puncture site swelling or becoming more painful, please inform the nurse.
  • You may experience some bruising around the puncture site, but this should fade over a few days.

If your procedure is performed through a blood vessel in the leg

  • One of the team will press on the leg vessel for 10 - 15 minutes to prevent any bleeding.
  • You will then be transferred back to the day case unit where you will have to lie flat for 2 hours.
  • After 2 hours you will be able to sit up, but you will still need to remain in bed for another 2 hours.
  • You will not be able to get out of bed for a total of 4 hours after the procedure.
  • During this time the nursing team will help you go to the toilet if needed.
  • If you are going to sneeze, cough or laugh, you must put firm pressure over the puncture site to protect the blood vessel from bleeding.
  • If you feel the leg puncture site swelling or becoming more painful, please inform the nurse.
  • You may experience some bruising around the puncture site, but this should fade over a few days.
  • If your procedure is performed through a leg vessel please rest your leg to enable healing. Avoid activities during the next three to five days which may strain your leg, such as running or lifting.

What are the risks associated with cerebral angiograms?

Potential complications are uncommon but include:

  • 1 in 1000 risk of a stroke with permanent symptoms.
  • 1 in 3000 risk of damage to the blood vessels in the neck which requires treatment.
  • 1 in 3000 risk of infection at the wrist or leg blood vessel puncture site.
  • 1 in 1500 risk of bleeding from the wrist or leg blood vessel puncture site which requires treatment such as a blood transfusion or an operation.
  • 1 in 750 risk of damage to the leg or wrist blood vessel. If damage occurs it may be necessary to perform a procedure to repair the damaged blood vessel, to prevent severe swelling or to maintain good blood supply to the affected limb.
  • 1 in 1500 risk of an allergic reaction to the x-ray dye, this could result in skin rash or breathing difficulties.
  • 1 in 20,000 risk of cancer related to the x-rays used in this procedure.
  • If a wrist blood vessel is used initially there is a chance the neuroradiologist may need to switch to using a leg blood vessel during the procedure, this happens in around 1 in 20 cases.
  • The risk of these complications is greatest in older patients and in patients who have come into hospital as an emergency due to bleeding in or around the brain.
  • Your neuroradiologist will discuss these with you again on the day of your procedure and you will be asked to sign a consent form to confirm you have understood these risks.

What happens next? 

The neuroradiologist will need to examine all the images very carefully before writing a report and possibly discuss findings with the doctor in charge of your case. Follow up will be arranged as appropriate.

If you experience any symptoms you are concerned about, please contact the Imaging department directly or alternatively contact your GP or the emergency department. The number for the Imaging department can be found on your appointment letter.

Finally, we hope this information is helpful. If you have any questions either before or after the procedure the staff in the Imaging department will be happy to answer them.


Information for patients undergoing an angiogram. RCR 2008 www.RCR.ac.uk

1. Shen, J., Karki, M., Jiang, T. & Zhao, B. Complications associated with diagnostic cerebral angiography: A retrospective analysis of 644 consecutive cerebral angiographic cases. Neurol India 66, 1154–1158 (2018).

2. Dawkins, A. A. et al. Complications of cerebral angiography: a prospective analysis of 2,924 consecutive procedures. Neuroradiology 49, 753–9 (2007).

3. Kaufmann, T. J. et al. Complications of Diagnostic Cerebral Angiography: Evaluation of 19 826 Consecutive Patients. Radiology 243, 812–819 (2007).

4. Fifi, J. T. et al. Complications of Modern Diagnostic Cerebral Angiography in an Academic Medical Center. J Vasc Interv Radiol 20, 442–447 (2009).

5. Johnston, D. C., Chapman, K. M. & Goldstein, L. B. Low rate of complications of cerebral angiography in routine clinical practice. Neurology 57, 2012–4 (2001).

6. Leffers, A. M. & Wagner, A. Neurologic complications of cerebral angiography. A retrospective study of complication rate and patient risk factors. Acta Radiologica Stock Swed 1987 41, 204–10 (2000).

7. Willinsky, R. A. et al. Neurologic Complications of Cerebral Angiography: Prospective Analysis of 2,899 Procedures and Review of the Literature. Radiology (2003) doi:10.1148/radiol.2272012071.

8. Thiex, R., Norbash, A. M. & Frerichs, K. U. The Safety of Dedicated-Team Catheter-Based Diagnostic Cerebral Angiography in the Era of Advanced Noninvasive Imaging. Am J Neuroradiol 31, 230–234 (2010).

9. Leonardi, M., Cenni, P., Simonetti, L., Raffi, L. & Battaglia, S. Retrospective Study of Complications Arising during Cerebral and Spinal Diagnostic Angiography from 1998 to 2003. Interv Neuroradiol 11, 213–221 (2005).

10. Schartz, D. et al. Complications of transradial versus transfemoral access for neuroendovascular procedures: a meta-analysis. J Neurointerv Surg neurintsurg-2021-018032 (2021) doi:10.1136/neurintsurg-2021-018032.

Public Health England “Guidance - Exposure to ionising radiation from medical imaging: safety advice” (2014)


How to contact us

Brunel building

Southmead Hospital



BS10 5NB

See your appointment letter for the number to phone with any queries you may have.

If you or the individual you are caring for need support reading this information please ask a member of staff for advice.

Cerebral angiogram