What are MRIs of the Orbits?

An MRI scan uses magnets and radio waves to capture images of your Orbits and surrounding nerves, muscles and tissues.  Sometimes a contrast agent, or dye, can be given through an intravenous (IV) line to better visualize certain structures or abnormalities.

Why do I need a MRI of my Orbits?

Your doctor may order an MRI of your Orbits alone, or with an MRI of the whole Brain. There are many reasons your doctor might order an MRI of the Orbits. This includes, but is not limited to:

• Vision loss or visual disturbances
• Vascular lesions
• Tumors or expected tumors
• Optic nerve sheath meningioma
• Optic nerve neuritis
• Optic nerve glioma
• Proptosis
• Orbital abcess
• Inflammation
• Extraocular myopathy
• Thyroid ophthalmopathy

How do I prepare for an Orbit MRI?

The medical staff will need to know if you have any metal in your body, including:

• inner ear implants
• artificial joints
• a defibrillator or pacemaker
• particular types of heart valves
• vascular stents
• brain aneurysm clips
• metal shrapnel
• bullets
• piercings
• pain pumps
• diabetic pumps
• penile implants

If you’re wearing anything that contains metal, including jewelry or sunglasses, you will need to remove those items. Metal interferes with the MRI machine’s ability to produce a clear image. Braces and dental fillings typically won’t pose a problem, but pocketknives, pens, pins, and certain dental appliances can interfere. The staff may ask you to wear a hospital gown or clothing that doesn’t contain metal fasteners. You cannot have electronic devices in the MRI room.

Tell the medical staff if you’re pregnant. An MRI’s magnetic field affects unborn children in a way that isn’t yet fully understood.

Additionally, it’s important to let the staff know if you are claustrophobic. If so, you might need to take sedatives during the exam or have an “open” MRI. Open MRI machines have wider tunnels, which tend to be more tolerable for claustrophobic patients.

During the exam, it’s important to stay still to obtain the clearest images.

You will lie down on a table that slides into the MRI machine. The table slides through a large magnet shaped like a tube. You may have a plastic coil placed around the area of concern. This is like an antenna and will direct the signal in the area of interest for more precise images. After the table slides into the machine, a technologist will take several pictures, each of which will take a few minutes. There will be a microphone in the machine that allows you to communicate with staff.

The test normally takes 30 to 60 minutes. You may receive a contrast solution, usually gadolinium, through an IV to allow the MRI machine to see certain parts of your anatomy more easily, particularly your blood vessels. The MRI scanner will make loud banging noises during the procedure. You may be offered earplugs or headphones to block the MRI machine’s noises.

There are no risks associated with an MRI itself. There is a very slight chance that you will have an allergic reaction to a contrast solution. Tell the medical staff if you have decreased kidney function. It may not be safe to use contrast solution if this is the case.

 Women shouldn’t breastfeed 24 to 48 hours after they’ve been given contrast dye. They need to wait for the dye to leave their bodies. 

After the test, you can get dressed and leave the testing facility. If you were sedated for the exam you will need to have someone with you, usually a friend or relative, to drive you afterwards.

A radiologist will analyze your MRI images and provide your doctor with the results. Next steps will depend on whether the results revealed anything unusual or discovered the cause of any abnormalities