About an orbits MRI scan
The orbits are the bony sockets that hold the eyes. Each contains the eyeball, the optic nerve that carries signals from the eye to the brain, the muscles that move the eye, the tear gland, blood vessels and fat. An orbits MRI uses a strong magnetic field and radio waves, not X-rays, to show these small structures in fine detail. Because it uses no radiation, it does not expose the lens of the eye to X-rays.
The scan is often requested by an eye specialist or neurologist. Common reasons include inflammation of the optic nerve (optic neuritis), which causes painful, blurred vision in one eye and can sometimes be an early sign of multiple sclerosis; thyroid eye disease, the most common cause of bulging eyes in adults, usually linked to Graves’ disease, where MRI can show swollen eye muscles and whether the disease is still active; and lumps, swelling or infection behind the eye. The scan often includes contrast and may be done alongside a brain MRI. You can read more in our article on orbits MRI.
What happens during the scan
You lie on your back on the scanner bed with a coil placed around your head. The scanner is loud, so you will wear ear plugs or headphones, and the radiographer can talk to you throughout. Eye movements blur the pictures, so you will be asked to keep your eyes still, usually by closing them gently or looking at one point, and to try not to blink during each scan. An injection of contrast dye (gadolinium) into a vein in your arm is often used; where contrast is needed, it is charged separately.
What the scan can show
An orbits MRI can help to look at:
- optic neuritis and other problems with the optic nerve
- thyroid eye disease, including swelling of the eye muscles
- bulging of one or both eyes (proptosis) and double vision
- lumps and growths in or behind the eye
- inflammation and infection in the eye socket
- the tear glands and blood vessels around the eye
When to get urgent help: sudden loss of vision, sudden double vision, or a painful red eye with swelling around it needs urgent assessment – contact an eye casualty department, NHS 111 or A&E rather than booking a scan.
Preparing for your scan
Do not wear eye make-up, such as mascara, eyeliner or eyeshadow, on the day of your scan. Some contain tiny metal particles that can distort the pictures of the eyes and may warm up in the scanner. Magnetic eyelashes and coloured or cosmetic contact lenses must also be removed; bring glasses if you need them.
Tell the centre if you have ever had metal in your eye, for example from welding, grinding or metalwork, even if it was removed. A small metal fragment in the eye can move in the magnetic field and damage the eye, so you may need an X-ray of the eyes before the scan. You can usually eat and drink normally.
You can usually eat, drink and take your normal medicines unless the scanning centre tells you otherwise. Wear loose, comfortable clothing without metal zips or buttons, and leave jewellery at home. You will be asked to remove metal items such as hair clips, hearing aids, coins and keys, and you may be asked to change into a gown.
Before the scan you will complete a safety questionnaire. Tell the team if you have a pacemaker, any metal implant, surgical clips or other device, if you have kidney problems or allergies, or if you are, or might be, pregnant or breastfeeding. If you feel anxious in enclosed spaces, let us know when you book. Some centres can offer a relaxant, and if you take one you will need someone to take you home and must not drive for 24 hours.
Frequently asked questions
Why can’t I wear eye make-up?
Some eye make-up contains iron oxide or other metal particles. These can spoil the pictures of the eyes, which are very close to the surface, and can occasionally irritate the skin. Please come with a clean face around the eyes.
I have worked with metal. Can I still have the scan?
Tell us when you book. If there is a chance of metal in your eye, the centre may arrange an X-ray of the eyes first to make sure it is safe.
Will I need a brain scan as well?
Sometimes. For optic neuritis, doctors often also want pictures of the brain. Your referrer will say which scans are needed; brain MRI is booked separately.
Do I need a referral?
You can tell us if you have a referral from your GP, physiotherapist or consultant and upload it when you book. If you do not have one, select “no referral” when you book and the scanning centre will confirm the next steps with you.
Sources
- Radiopaedia – Thyroid-associated orbitopathy
- MS Trust – Optic neuritis
- Mascara – an unsuspected cause of magnetic resonance imaging artifact (PubMed)
- MRI Questions – Orbital foreign bodies
- NHS – MRI scan
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.