What is a lower extremity MRI?
A lower extremity MRI is a magnetic resonance image of some part of the body beneath the groin. Magnetic resonance imaging uses a combination of extremely strong magnets and radio waves to see inside the body. Unlike an X-ray, these scans show the soft tissue that surrounds the bones in amazing detail. This allows doctors to see damage to the muscles, nerves, blood vessels, and tendons surrounding the joints.
Why would I get a lower extremity MRI?
One of the most common reasons to order an MRI of the lower extremity is an injury to the knee that is concerning for damage to the ligaments inside or around the knee. MRIs of the hips and ankles may also be done if there is a concern for a serious injury that will not show up on an x-ray. Some of the common conditions that are diagnosed with a lower extremity MRI are:
- A torn ACL, PCL, or MCL (ligaments in the knee)
- A hip fracture
- Weak ligaments in the ankles causing repeated ankle sprains
- Torn tendons or muscles
- Metastatic cancer
How is an MRI of the lower leg done?
An MRI of the lower leg is extremely simple for the patient. All you have to do during an MRI is sit still. You are placed on a table that moves in and out of a doughnut-shaped scanner which creates the image. The hardest part of an MRI is lying completely still as a full lower leg MRI can take 1-2 hours.
Does your whole body go in for a leg MRI?
In most cases, only one joint will be imaged for an MRI. For a hip MRI, most of your lower body may pass through the MRI scanner. Imaging of the ankle or knees only requires those areas to pass through the scanner.
Can an MRI be done on both legs at the same time?
Yes! This is a rare occurrence as most of the reasons for lower extremity MRIs are injuries that are causing ongoing pain. It is rare for both legs to be injured in the same way at the same time. Because of this, only one leg typically requires an MRI. If required for whatever reason, the vast majority of MRI scanners can accommodate scanning both legs at the same time.
What should I wear for a leg MRI?
Wear comfortable clothing that can be easily removed if required by the facility that is performing your MRI. Most importantly, make sure that your clothing has no metal on it! No snaps, zippers, buttons, or metal details. An MRI uses an immensely strong magnet which will attract metal and injure you while damaging the magnet. For this reason, many doctors will require you to be in a hospital-style gown for any MRI.
Can an MRI detect poor circulation?
An MRI is not the best test for assessing circulation. Vascular surgeons will typically recommend an angiogram, CT scan with contrast, or they will perform a procedure known as a catheterization to directly look at the blood vessels using a special x-ray machine. An MRI is a much slower way of getting images of the body that is too slow to reliably show the small changes in blood flow used to diagnose poor circulation.
