Magnetic resonance imaging (MRI) is a type of scan that produces a 3-dimensional image of your internal body parts. MRIs produce a clearer image of soft tissue than CT scans and X-rays, so they’re often used to help diagnose conditions involving:
- nerves and your brain
- blood vessels
An MRI works by using strong magnets to align protons in your body. Short bursts of radio waves are sent through your body to knock these protons out of alignment. Between pulses of radio waves, the protons realign and send out signals that allow the MRI machine to create images.
According to the National Health Service, most types of MRIs take roughly 15 to 90 minutes to complete, but they can be shorter or longer depending on the number of images that need to be taken and the part of your body being scanned.
Let’s take a closer look at how long some of the most common types of MRIs typically take.
An MRI of your knee can be used to help identify the following around your knee joint:
The MRI usually takes about 30 to 60 minutes. During the procedure, small devices containing coils may be put around your knee to help produce a clearer image.
An MRI of your shoulder typically takes about 15 to 45 minutes. In some cases, the procedure may be as quick as 15 minutes.
RadiologyInfo.org says that procedures that require sedation may take 15 to 30 minutes longer.
An MRI of your head can help identify conditions affecting your brain. The scan typically takes about 30 to 60 minutes.
According to Cincinnati Children’s Hospital and Medical Center, scans that don’t require a contrast dye are generally shorter and may only take 30 to 45 minutes. Some procedures like the limited brain MRI only take about 5 minutes.
An MRI of your lumbar spine can potentially help identify causes of back pain and conditions involving your spinal cord. A spinal scan takes about 30 to 60 minutes. If a contrast die is needed, the procedure may take 45 to 80 minutes.
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An MRI of your heart is typically completed in under 90 minutes, according to RadiologyInfo.org. This scan may be able to identify if you’re at risk of developing heart failure or if you currently have a heart condition.
An abdominal MRI generally takes about 30 to 90 minutes. In some cases, it may take up to about 2 hours. Abdominal MRIs are used for a variety of reasons, such as examining:
- blood flow
- abdominal swelling
- fetal development
A hip MRI generally takes around 45 minutes. The majority of MRIs for hip pain take roughly 30 to 60 minutes.
According to the National Health Service, an ankle MRI typically takes about 40 minutes. In some cases, it can take up to 1 hour.
A pelvic MRI generally takes about 30 to 60 minutes. If many pictures are needed, the procedure may take longer.
A chest MRI typically takes less than 90 minutes. You may need a chest scan if you have an injury or suspected condition in your chest area.
A breast MRI typically takes about 30 to 60 minutes, according to RadiologyInfo.org. In some cases, you may have a contrast dye injected into your arm via an intravenous (IV) before your procedure. If you require contrast dye, your procedure may take up to 90 minutes.
The following factors play a role in determining how long your MRI will take.
- The number of images. If many images are needed for a detailed analysis, your MRI will take longer than a scan taking fewer images.
- The part of your body getting scanned. In general, the larger the area of your body that needs to be scanned, the longer the MRI will take.
- Contrast dyes. Sometimes a contrast dye is given through an IV to help small structures appear more clearly on the images. MRIs that require a contrast dye may take an extra 15 to 30 minutes, according to RadiologyInfo.org.
- Sedation. MRIs are sensitive to movement so people who can’t stay still, like some young children and people will claustrophobia, may require sedation before the procedure. Sedatives may be oral or administered through an IV.
The amount of time it takes to get your MRI results depends on factors like the hospital or clinic you visit and the seriousness of your condition. Generally, it takes about 1 to 2 weeks to get your results, according to the National Health Service. You may get your results quicker if you’re dealing with a condition that requires urgent attention.
When you arrive at the hospital, you’ll likely be asked to fill out a questionnaire with your medical history and to confirm that you don’t have a metal implant or pacemaker that may prevent you from having an MRI scan.
You may be asked to change into a hospital gown to ensure you don’t have any metal on your clothes that may interfere with the MRI. You may also be given a sedative or contrast dye through an IV before your procedure.
During the scan, you’ll lie on a bed inside the cylindrical MRI scanner. A coil may be placed over the part of your body being scanned to help produce a clearer image. The radiographer operating the MRI will be in a separate room, but you’ll still be able to talk with them through an intercom.
You’ll remain still as the machine scans your body. You’ll likely hear loud tapping noises and may be given earplugs or headphones. Each scan may take from seconds to about 4 minutes, according to the National Health Service. The radiographer may ask you to hold your breath during some shorter scans.
You’ll be free to go immediately after your procedure. If you had a sedative, you’ll need somebody to drive you and you won’t be able to drink alcohol or operate heavy machinery for at least 24 hours.
Most types of MRIs take about 15 to 90 minutes to complete. In some cases, your MRI might be shorter or longer. The part of your body getting scanned and the number of images needed to play a role in determining how long the MRI will take.
If your MRI requires contrast dye, it will typically last a little longer than MRIs that don’t require it.