A lumbar magnetic resonance imaging (MRI) scan uses energy from strong magnets to create pictures of the lower part of the spine (lumbar spine).
An MRI does not use radiation (x-rays).
Single MRI images are called slices. The images can be stored on a computer or printed on film. One exam produces many images.
Related exams include:
Magnetic resonance imaging - lumbar spine; MRI - lower back
You will wear a hospital gown or clothes without metal snaps or zippers (such as sweatpants and a t-shirt). Make sure you take off your watch, jewelry and watches. Some types of metal can cause blurry images.
You will lie on a narrow table that slides into a large tunnel-like tube.
Some exams require a special dye (contrast). Most of the time, you will get the dye through a vein (IV) in your hand or arm before the test. You can also get the dye through an injection. The dye helps the radiologist see certain areas more clearly.
During the MRI, the person who operates the machine will watch you from another room. The test most often lasts 30 to 60 minutes, but may take longer.
You may be asked not to eat or drink anything for 4 to 6 hours before the scan.
Tell your health care provider if you are afraid of closed spaces (have claustrophobia). You may be given a medicine to help you feel sleepy and less anxious. Your provider may suggest an "open" MRI, in which the machine is not as close to the body.
Before the test, tell your provider if you have:
Because the MRI contains strong magnets, metal objects are not allowed into the room with the MRI scanner:
An MRI exam causes no pain. You will need to lie still as too much movement can blur MRI images and cause errors.
The table may be hard or cold, but you can ask for a blanket or pillow. The machine makes loud thumping and humming noises when turned on. You can wear ear plugs to help block out the noise.
An intercom in the room lets you to speak to someone at any time. Some MRIs have televisions and special headphones that you can use to help the time pass.
There is no recovery time, unless you were given a medicine to relax. After an MRI scan, you can return to your normal diet, activity, and medicines.
You may need a lumbar MRI if you have:
Your provider may also order a lumbar MRI if you have:
A normal result means your spine and nearby nerves look OK.
Most of the time, abnormal results are due to:
Other abnormal results may be due to:
Talk to your provider about your questions and concerns.
MRI contains no radiation. There have been no reported side effects from the magnetic fields and radio waves.
It is also safe to have MRI performed during pregnancy. No side effects or complications have been proven.
The most common type of contrast (dye) used is gadolinium. It is very safe. Allergic reactions to this dye are rare. However, gadolinium can be harmful to people with kidney problems that need dialysis. If you have kidney problems, please tell your provider before the test.
The strong magnetic fields created during an MRI can cause heart pacemakers and other implants to not work as well. It can also cause other pieces of metal inside your body to move or shift. For safety reasons, please do not bring anything that contains metal into the scanner room.
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Reviewed By: C. Benjamin Ma, MD, Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.