What is CT Angiography (CTA) of the Head?
CT angiography (CTA) is a diagnostic imaging study that combines the use of a high-tech rotating X-ray machine, a contrast dye injected into your vein, and sophisticated computer analysis to produce high-resolution 3D images of the blood vessels in your head.
Uses of CT Angiography of the Head
Abnormal conditions that can be identified by CTA of the head include:
- Arteriovenous malformations
- Subdural hematoma
- Narrowing or blockage of arteries
- Rupture or tear in the wall of a blood vessel
- Brain aneurysm
- Brain tumors
How does the CT scan Work?
In the CT machine, an X-ray tube circles around your head taking pictures that capture narrow slices of your head at a time. This eliminates the overlap or shadow caused by surrounding tissues, which occurs with normal X-rays. The contrast medium injected into the vein further enhances the image of the blood vessels as it circulates in the bloodstream. The high-resolution images which are produced can be viewed individually or added together to create 3D images of the blood vessels in the head.
Indications for CT Angiography (CTA) of the Head
CT Angiography (CTA) of the head may be ordered to investigate symptoms such as:
- Loss of consciousness
- Double vision or blurry vision
- Altered sensation in the face or scalp
- Transient ischemic attacks
- Chronic headaches
- Hearing loss
- Swallowing problems
- Weakness in one part of the body
- Difficulty with speech
- Changes in behavior or cognition
Preparation for CT Angiography (CTA) of the Head
- Inform your doctor regarding any health conditions, previous surgeries, the likelihood of pregnancy, and any allergies.
- Leave all jewelry at home. Wear loose-fitting comfortable clothing that does not contain any metal fasteners, or you may be asked to wear a hospital gown.
- If a contrast dye is used, you will need to avoid eating or drinking a few hours before the procedure.
- You can continue to take your regular medications unless otherwise specified.
Procedure for CT Angiography of the Head
The procedure for CT angiography of the head involves the following basic steps:
- You will be placed comfortably on a movable scanning table.
- An IV line will be placed into your arm to inject the contrast material.
- The scanning table will be slid into the center of the CT scanner.
- Lines of light will be projected onto your body to ensure you are in the correct position.
- The table will then slowly move through the machine as the scanning is performed.
- You will be asked to hold your breath and avoid movement to ensure high-quality images.
- You may hear clicking, buzzing, or whirring sounds as the internal parts of the CT scanner move around you during the procedure.
- Once the imaging process is complete, the table will be slid out of the CT scanner, the IV line will be removed, and a dressing applied at the line insertion site.
- The procedure will usually be completed within 10 minutes.
What happens after CT Angiography of the Head?
You can return to your routine activities and resume your normal diet immediately after the procedure. Drinking plenty of water during the first 24 hours to help remove the contrast dye from your body is recommended. If sedation was provided to help you relax, you may have to wait until the effects of sedation wear off before returning to your routine activities. A radiologist or trained doctor will analyze the images and send the report to your doctor, who will share the results with you.
Risks of CT Angiography of the Head
- The is a minimal risk of cancer from excessive or repeated exposure to radiation.
- There may be an allergic reaction to contrast dye. These reactions are usually mild and can be easily controlled with medication.
Benefits of CT Angiography of the Head
- Painless and non-invasive procedure
- Produces highly detailed images of the blood vessels of the brain and associated cranial structures
- Less sensitive to patient movement as compared to an MRI
- Fast and simple procedure that can detect internal injury or bleeding within the brain quickly.