MRI of the Spine
Magnetic resonance imaging (MRI) is a noninvasive medical test that helps physicians diagnose and treat medical conditions.
MRI uses a powerful magnetic field, radio frequency pulses and a computer to produce detailed pictures of organs, soft tissues, bone and virtually all other internal body structures. The images can then be examined on a computer monitor, printed or copied to a CD. MRI does not use ionizing radiation (x-rays).
Detailed MR images allow physicians to better evaluate various parts of the body and determine the presence of certain diseases that may not be assessed adequately with other imaging methods such as x-ray, ultrasound or computed tomography (also called CT, MDCT or CAT scanning).
An MRI examination of the spine shows the anatomy of the vertebrae that make up the spine, as well as the disks, spinal cord and the spaces between the vertebrae through which nerves pass.
Currently, MRI is the most sensitive imaging test of the spine in routine clinical practice.
What are some common reasons the scan is ordered?
MR imaging is performed to:
- Evaluate the spinal anatomy
- Visualize variations in spinal anatomy
- Look for diseased tissue in the spine
- Help plan surgeries on the spine such as decompression of a pinched nerve or spinal fusion
- Monitor changes in the spine after an operation, and look for scarring or infection
- Guide the injection of steroids to relieve spinal pain
- Evaluate the disks between the vertebrae to look for bulging, degeneration or herniation
- Evaluate the joints between the vertebrae
- Evaluate compressed (or pinched) and inflamed nerves
- Explore possible causes of back pain (compression fracture for example)
- Look for spinal infection or tumors that arise in, or have spread to, the spine
How should I prepare?
- You may be asked to wear a gown during the exam or you may be allowed to wear your own clothing if it is loose-fitting and has no metal fasteners
- Guidelines about eating and drinking before an MRI exam vary with the specific exam and also with the facility. Unless you are told otherwise, you may follow your regular daily routine and take food and medications as usual
- Some MRI examinations may require the patient to receive an injection of contrast material into the bloodstream. The technologist may ask if you have allergies of any kind, such as allergy to iodine or x-ray contrast material, drugs, food, the environment, or asthma. However, the contrast material most commonly used for an MRI exam, called gadolinium, does not contain iodine and is less likely to cause side effects or an allergic reaction
- The radiologist should also know if you have any serious health problems or if you have recently had surgery. Some conditions, such as severe kidney disease may prevent you from being given contrast material for an MRI. If there is a history of kidney disease, it may be necessary to perform a blood test to determine whether the kidneys are functioning adequately
- Women should always inform their physician or technologist if there is any possibility that they are pregnant. MRI has been used for scanning patients since the 1980s with no reports of any ill effects on pregnant women or their babies. However, because the baby will be in a strong magnetic field, pregnant women should not have this exam unless the potential benefit from the MRI exam is determined to outweigh the potential risks. This should be discussed with your physician. Pregnant women should not receive injections of contrast material. If you have claustrophobia (fear of enclosed spaces) or anxiety, you may want to ask your physician for a prescription for a mild sedative prior to the scheduled examination
- Jewelry and other accessories should be left at home if possible, or removed prior to the MRI scan. Because they can interfere with the magnetic field of the MRI unit, metal and electronic objects are not allowed in the exam room. These items include:
- jewelry, watches, credit cards and hearing aids, all of which can be damaged
- pins, hairpins, metal zippers and similar metallic items, which can distort MRI images.
- removable dental work
- pens, pocketknives and eyeglasses
- body piercing
- In most cases, an MRI exam is safe for patients with metal implants, except for a few types. People with the following implants cannot be scanned and should not enter the MRI scanning area unless explicitly instructed to do so by a radiologist or technologist who is aware of the presence of any of the following:
- internal (implanted) defibrillator or pacemaker
- cochlear (ear) implant
- some types of clips used on brain aneurysms
- some types of metal coils placed within blood vessels
- You should tell the technologist if you have medical or electronic devices in your body, because they may interfere with the exam or potentially pose a risk, depending on their nature and the strength of the MRI magnet. Examples include but are not limited to:
- artificial heart valves
- implanted drug infusion ports
- implanted electronic device, including a cardiac pacemaker
- artificial limbs or metallic joint prostheses
- implanted nerve stimulators
- metal pins, screws, plates, stents or surgical staples
- In general, metal objects used in orthopedic surgery pose no risk during MRI. However, a recently placed artificial joint may require the use of another imaging procedure. If there is any question of their presence, an x-ray may be taken to detect the presence of and identify any metal objects
- Patients who might have metal objects in certain parts of their bodies may also require an x-ray prior to an MRI. You should notify the technologist or radiologist of any shrapnel, bullets, or other pieces of metal which may be present in your body due to accidents. Dyes used in tattoos may contain iron and could heat up during MRI, but this is rarely a problem. Tooth fillings and braces usually are not affected by the magnetic field but they may distort images of the facial area or brain, so the radiologist should be aware of them
What should I expect?
- The MRI machine looks like a tunnel or donut that has both ends open. You lie down on a movable table that slides into the opening of the tunnel. A technologist monitors you from another room. You can talk with him or her by microphone
- The MRI machine creates a strong magnetic field around you, and radio waves are directed at your body. The procedure is painless. You don't feel the magnetic field or radio waves, and there are no moving parts around you
- During the MRI scan, the internal part of the magnet produces repetitive tapping, thumping and other noises. Earplugs or music may be provided to help block the noise. If you are worried about feeling claustrophobic inside the MRI machine, talk to your doctor beforehand. He or she may make arrangements for you to receive a sedative before the scan
- An MRI typically lasts less than an hour. You must hold very still because movement can blur the resulting images. In some cases, contrast agents are injected into your veins to enhance the appearance of certain tissues or blood vessels in the images
Who interprets the results and how do I get them?
One of our board certified radiologists will analyze the images and send a report to your primary care physician and the physician who referred you for the exam. This detailed report will be sent to your physician’s office within 24-48 hours. The physician’s office will call you or the results will be reviewed at your next appointment.
What are the benefits of a MRI Spine scan?
- MRI is a noninvasive imaging technique that does not involve exposure to ionizing radiation
- MR images of the spine are clearer and more detailed than images obtained with other imaging methods. This detail makes MRI an invaluable tool in early diagnosis and evaluation of many spinal conditions, including tumors
- MRI has proven valuable in diagnosing a broad range of conditions including, but not limited to, congenital conditions, chronic spinal cord diseases (such as multiple sclerosis), bone abnormalities (e.g., fracture), disk conditions (e.g., herniated disk), vascular anomalies, infections and tumors
- MRI enables the discovery of abnormalities that might be obscured by bone with other imaging methods
- The contrast material used in MRI exams is less likely to produce an allergic reaction than the iodine-based contrast materials used for conventional x-rays and CT scanning
- MRI demonstrates abnormalities, injuries and diseases in the spinal region that may not be visualized with other imaging methods
- MRI is very useful for evaluating spinal injuries. It is especially helpful for diagnosing or ruling out acute compression of the spinal cord when clinical examination shows muscle weakness or paralysis
- MRI is able to detect subtle changes in the vertebral column that may be an early stage of infection or other abnormality. The procedure is more sensitive than CT scanning for evaluating structures near the spinal cord
What are the risks of a MRI Spine scan?
- The MRI examination poses almost no risk to the average patient when appropriate safety guidelines are followed
- If sedation is used there are risks of excessive sedation. The technologist or nurse monitors your vital signs to minimize this risk
- Although the strong magnetic field is not harmful in itself, implanted medical devices that contain metal may malfunction or cause problems during an MRI exam
- There is a very slight risk of an allergic reaction if contrast material is injected. Such reactions usually are mild and easily controlled by medication. If you experience allergic symptoms, a radiologist or other physician will be available for immediate assistance
- Nephrogenic systemic fibrosis is currently a recognized, but rare, complication of MRI believed to be caused by the injection of high doses of gadolinium contrast material in patients with very poor kidney function
If you have any questions/concerns about your MRI exam, please call us at (724) 225-7000 and ask for the MRI department.
If you should have to cancel your appointment, please contact us at (724) 250-4300 as soon as possible.
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