Lumbosacral spine MRI Health Article

Why the test is performed

MRI is an imaging test used to look into back pain and spreading leg pain. MRI is excellent at showing changes, such as from arthritis, which may be narrowing the spaces through which the spinal nerves travel.

In addition, MRI can show disease of the lumbar discs that may be bulging and compressing the spinal cord.

An MRI may be done after traumatic injury if you have weakness or paralysis. MRI is better than CT scans at evaluating abscesses, tumors, or other masses near the spinal cord. While CT is better at detecting fractures of the vertebrae, MRI can detect slight changes in the bone which may be due to an infection or tumor.

What the risks are

There is no ionizing radiation involved in MRI. To date, there have been no significant side effects reported from the magnetic fields and radio waves used on the human body during an MRI scan.

The most common MR contrast dye, gadolinium, is very safe. However, you should not receive gadolinium if you are pregnant because of potential harm to the unborn baby. In very rare cases, patients have had allergic reactions to this contrast dye.

There have been recent reports of fibrotic skin diseases in patients with severe kidney failure who received MRI dye. If you have severe kidney failure, tell your doctor before the study.

If sedation is used, there are risks of too much sedation. The technician will monitor your vital signs, including heart rate and breathing, as needed.

People have been harmed in MRI machines when they did not remove metal objects from their clothes or when metal objects were left in the room by others.

Special considerations

MRI is more accurate than a CT scan or other tests for certain conditions, but less accurate for others. The disadvantages include:

• High cost
• Sensitivity to movement
• Time involved with the scan

People with a fear of enclosed spaces (claustrophobia), or who are confused or anxious, may have difficulty lying still during the scan.

MRI is not portable and is does not work with:

• Life support-devices
• Some metallic implants
• Traction equipment

MRI is a preferred technique in most cases where telling differences in soft tissues is necessary. It can show organs without being blocked by bones and foreign bodies. It can show the tissues from many viewpoints and is a noninvasive way to evaluate blood flow.