Magnetic resonance imaging - lumbar spine; MRI - lower back DefinitionA 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:
How the Test is PerformedYou 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. MRIs can pull on any metallic objects. 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. How to Prepare for the TestYou 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:
How the Test will FeelAn 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. Why the Test is PerformedThe most common reasons for this test are:
Your provider may also order a lumbar MRI if you have:
Normal ResultsA normal result means your spine and nearby nerves look OK. What Abnormal Results MeanMost of the time, abnormal results are due to:
Other abnormal results may be due to:
Talk to your provider about your questions and concerns. RisksMRI uses 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. ReferencesChou R, Qaseem A, Owens DK, Shekelle P; Clinical Guidelines Committee of the American College of Physicians. Diagnostic imaging for low back pain: advice for high-value health care from the American College of Physicians. Ann Intern Med. 2011;154(3):181-189. PMID: 21282698 pubmed.ncbi.nlm.nih.gov/21282698/. Sack KD, Rosner MK. Evaluation and treatment of lumbar disk disease. In: Winn HR, ed. Youmans and Winn Neurological Surgery. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 318. Gardocki RJ, Park AL. Degenerative disorders of the thoracic and lumbar spine. In: Azar FM, Beaty JH, eds. Campbell's Operative Orthopaedics. 14th ed. Philadelphia, PA: Elsevier; 2021:chap 39. Samad A, Usmani MF, Khanna AJ. Imaging of the spine. In: Miller MD, Thompson SR, eds. DeLee, Drez, & Miller's Orthopaedic Sports Medicine. 5th ed. Philadelphia, PA: Elsevier; 2020:chap 124. Van Thielen T, van den Hauwe L, Van Goethem JW, Parizel PM. Current status of imaging of the spine and anatomical features. In: Adam A, Dixon AK, Gillard JH, Schaefer-Prokop CM, eds. Grainger & Allison's Diagnostic Radiology. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 47. | |
| |
Review Date: 4/24/2023 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 C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, timeliness, or correctness of any translations made by a third-party service of the information provided herein into any other language. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited. | |
| |
