About a CT scan of the face
The face is made up of many small bones, including the eye sockets (orbits), cheekbones (zygoma), upper jaw (maxilla), nose and lower jaw (mandible), with the air-filled sinuses between them. A CT (computed tomography) scan uses X-rays and a computer to make thin cross-section pictures of these bones, which can be turned into 3D images. CT shows bone in more detail than any other scan and is the main test for facial bones.
The most common reason for a facial CT is a fracture after an injury, such as a broken cheekbone, eye socket or jaw. A CT shows exactly where the bones have broken and how far they have moved, which helps surgeons decide whether an operation is needed. 3D images are often used to plan surgery. A broken nose on its own usually does not need a scan.
A facial CT may also be used to look at:
- problems with the shape or alignment of the face and jaw, before corrective (orthognathic) or reconstructive surgery
- bony lumps, cysts and growths
- infections that have spread into the bones or soft tissues of the face
- the facial bones after surgery, including plates and screws
For the sinuses alone, a dedicated sinus CT is usually used, and for soft-tissue problems such as lumps in the salivary glands, MRI or ultrasound may be better; see face and facial bones MRI. Your referrer will say which scan is best.
What happens during the scan
You lie on your back on the scanner bed with your head resting in a cradle, and pads may be used to help you keep still. Only your head goes into the scanner, which is a short, open ring. The radiographer controls the scanner from the next room, but can see, hear and talk to you throughout. The scan itself takes less than a minute. Contrast dye is not usually needed, but may be used to look at an infection or lump; where contrast is needed, it is charged separately.
Is CT safe?
CT uses X-rays, which are a type of ionising radiation. A CT of the face gives a dose similar to or lower than a CT of the head (about 2 mSv, similar to around 1 year of natural background radiation). Centres use techniques to reduce the dose to the eyes. The risk from a single scan is very small, and every CT scan is checked by a radiologist or radiographer to make sure the benefit of the scan outweighs the risk, as required by the Ionising Radiation (Medical Exposure) Regulations. If you have had other CT scans recently, tell us when you book.
What the scan can show
A CT scan of the face can help to look at:
- fractures of the eye sockets, cheekbones, upper jaw and lower jaw
- planning for facial and jaw surgery
- bony lumps, cysts and growths
- infections of the facial bones and tissues
- the position of plates and screws after surgery
When to get urgent help: go to A&E if you have a facial injury with double vision, changes to your eyesight, numbness of your cheek or upper lip, teeth that no longer meet properly, clear fluid running from your nose, or if you were knocked out. Call 999 if you have facial swelling with difficulty breathing or swallowing.
Preparing for your scan
No special preparation is needed, and you can eat and drink normally. Remove glasses, earrings, hair clips and removable dental work before the scan. Upload any previous X-ray or scan reports and letters from your surgeon when you book.
Wear loose, comfortable clothing without metal zips, poppers or buttons, and leave jewellery at home, as metal in the scan area can affect the pictures. You may be asked to change into a gown. Unlike MRI, CT is not affected by pacemakers or most metal implants, and the scanner is a short open ring rather than a tunnel, so it is usually easier for people who feel anxious in enclosed spaces.
Tell the team before your scan if you are, or might be, pregnant or breastfeeding, if you have kidney problems, diabetes (especially if you take metformin), asthma, thyroid problems or allergies, or if you have had a reaction to contrast dye before. If you need contrast, you may be asked for a recent kidney blood test result.
Frequently asked questions
Do I need a scan for a broken nose?
Usually not. A broken nose is normally diagnosed by examination. A CT may be needed if other bones of the face may also be broken.
Is CT or MRI better for the face?
CT is better for the bones, such as fractures and surgical planning. MRI is better for soft tissue, such as lumps in the glands or around the eyes. Your referrer will say which is needed; if you are unsure, contact us before booking.
I have metal plates in my face. Can I still have a CT?
Yes. CT is often used after facial surgery to check plates and screws. Tell us about any implants when you book.
Do I need a referral?
Because CT uses radiation, each scan has to be justified by a qualified professional before it can go ahead. Upload a referral from your GP or consultant when you book if you have one. If you do not, select “no referral” and the scanning centre will review your request and confirm the next steps with you, which may include arranging a referral.
Sources
- Diagnostic tools in maxillofacial fractures: is there really a need of three-dimensional computed tomography? (PMC)
- Imaging of mandibular fractures: a pictorial review (PMC)
- Computed tomography imaging strategies and perspectives in orbital fractures (PMC)
- NHS – Broken nose
- NHS – CT scan
- UKHSA – Patient dose information: guidance
The information on this page has been gathered from various sources and is provided for general information only. It is not medical advice. TOP MRI is not liable for the accuracy or completeness of this information. Please speak to your doctor or the scanning centre about your own situation.