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Spine MRI How the Test is Performed:
The MRI scanner is in an area that has been shielded from outside magnetic fields. You are asked to lie on a narrow table that can slide inside a large tunnel-like tube within the scanner. The scanner creates a magnetic field around you, then pulses radio waves at the tissues in question. Several sets of images are usually required, each taking from 2 to 15 minutes. The complete scan takes about 1 hour; some scans take more than 90 minutes.
How to Prepare:
No preparatory tests, diets, or medications are usually needed. Occasionally the person may be asked to fast for 4 to 6 hours prior to the scan. You must sign a consent form before the scan.
Because of the strong magnets, no metallic objects are allowed into the room. Items such as jewelry, watches, credit cards, and hearing aids can be damaged by the strong magnets. Pins, hairpins, metal zippers, and similar metallic items can distort the images. Frequent exposure to ferrous metals (such as a sheet metal worker has) may make MRI difficult. A hospital gown may be recommended, or you may be allowed to wear "sweats" or similar clothing without metal fasteners. Take out removable dental work just prior to the scan.
Infants and children:
The physical and psychological preparation you can provide for this or any test or procedure depends on your child's age, interests, previous experience, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child's age:
How it Feels:
There is no pain. The magnetic field and radio waves are not felt. The primary discomfort is the claustrophobic feeling that some people experience from being inside the scanner. The table may be hard or cold, but you may request a blanket or pillow. The machine produces loud thumping and humming noises. Ear plugs are usually given to reduce the noise. A technologist observes you during the entire procedure and may enter the room to speak to you or may speak through an intercom in the scanner.
Excessive movement can blur MRI images. If you have difficulty lying still or are very anxious, you may be given a sedative. There is no recovery required (unless you have been sedated). After an MRI scan, you can resume a normal diet, activity, and medications.
Risks:
There is no ionizing radiation, and usually no contrast dye is needed. The procedure is safe in most cases, and there are no documented side effects. However, because the effects of magnetic fields on a fetus are not well researched at this time, pregnant women are usually advised to avoid MRI scans.
Because the strong magnets can displace or disrupt the action of implanted metallic objects, people with cardiac pacemakers cannot be scanned and should not enter the MRI scan area. MRI also should not be used for most people with metallic objects in their bodies, such as artificial joints, inner ear (cochlear) implants, brain aneurysm clips, some artificial heart valves, and metallic foreign bodies in the eye or other body areas. MRI is usually not recommended for acute trauma situations because traction and life support equipment cannot enter the scanner area and because of the long scan times.
Why this Test is Performed:
MRI may show the exact location of tumors or other lesions of the spine, spinal cord, or intervertebral disks. It provides detailed pictures of hard-to-view areas of the spine, including the spinal canal, bony segments, and soft tissue. MRI is sometimes used to avoid the dangers of exposure to contrast dye or radiation.
Normal Values:
No abnormalities of size or position of the spine or spinal cord as viewed from any plane. No new growths or lesions.
Abnormal Results:
The sensitivity of MRI depends, in part, on the experience of the radiologist. As MRI becomes more common, increasingly detailed diagnosis may be possible.
Spine MRI may reveal disorders such as: Additional conditions under which the test may be performed:
Cost:
The estimated cost is $860 to $2000.
MRI is more expensive than X-rays or CT scans, mostly because the equipment is very expensive. However, MRI may replace multiple other tests, and provides a clear image with a very low risk. The benefits often outweigh the cost of the scan.
Most insurance companies will pay for MRI scans. Some scans of certain body areas or for certain medical conditions may not be covered by all insurances, so check with the insurance company.
Special Considerations:
MRI is more accurate than CT scan or other tests for certain conditions, but less accurate for others. Disadvantages include the high cost, long duration of the scan, and sensitivity to movement. People with claustrophobia or who are confused or anxious may have difficulty lying still for the relatively long scan times. MRI is not portable and is incompatible with metallic implants, life support devices, traction apparatus, and similar equipment.
MRI is superior in most cases in which differentiation of soft tissues is necessary. It can view organs and tissues that are inside of bone. It is capable of showing the tissues from multiple viewpoints and is noninvasive .
MRI stands for magnetic resonance imaging. It is a relatively new technology that allows imaging of the interior of the body without using X-rays or other types of ionizing radiation. An MRI scan is capable of showing fine detail of different tissues. Its use is rapidly increasing while the use of standard X-rays has decreased.
The spine is divided into several sections. The cervical vertebrae make up the neck. The thoracic vertebrae comprise the chest section and have ribs attached. The lumbar vertebrae are the remaining vertebrae below the last thoracic bone and the top of the sacrum. The sacral vertebrae are caged within the bones of the pelvis, and the coccyx represents the terminal vertebrae or vestigial tail.
These are the five vertebra of the lower back. The last vertebra (on the upper left of the picture) attaches to the sacrum, and the top vertebra (on the right of the picture) attaches to the thoracic section of the back. The vertebra are broader and stronger than the other bones in the spine. This allows them to absorb the added pressure applied to the lower back, but this area remains a common sight of injury. The vertebra are numbered from one to five and are labeled L1, L2, L3 etc. from the higher bones to the lower.
These are twelve vertebra of the mid back. The last vertebra (on the left side of the picture) attaches to the lumbar (lower) spine, and the top vertebra (on the right) attaches to the cervical (neck) section of the back. The vertebra are broader and stronger than the cervical bones. This allows them to absorb the added pressure applied to the mid back, but they remain a common sight of injury. The vertebra are numbered from one to twelve and labeled T1, T2, T3 etc. from the upper most bones to the lowest.
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