Magnetic Resonance Imaging (MRI) of the Knee
Magnetic resonance imaging (MRI) is a test
done with a large machine that uses a magnetic field and pulses of radio wave
energy to make pictures of the knee . Muscles,
cartilage, and other joint structures are often best
seen with an MRI. In many cases MRI gives information about structures in the
body that cannot be seen as well with an
For an MRI test, you are placed
inside the magnet so that your knee is inside the strong magnetic field. MRI
can find changes in the structure of organs or other tissues. It also can find
tissue damage or disease, such as infection or a tumor. Pictures from an MRI
scan are digital images that can be saved and stored on a computer for further
study. The images also can be reviewed remotely, such as in a clinic or an
operating room. Photographs or films of selected pictures can also be made.
In some cases, a
contrast material may be used during the MRI scan to
show certain structures more clearly in the pictures. The contrast material may
be used to check blood flow, find some types of tumors, and show areas of
inflammation or infection. The contrast material may be put in a vein (IV) in your arm or directly into your knee.
There are two main types of MRI—the standard MRI machine and the
open MRI machine .
Why It Is Done
Magnetic resonance imaging (MRI) of the
knee is done to:
- Check for the cause of unexplained knee pain or
the knee giving out for no reason.
- Find problems in the knee joint ,
arthritis, bone tumors, or infection, or damaged
meniscus , ligaments, or
- Find out if a knee
arthroscopy is needed.
MRI may also find a bone fracture when X-rays and other
tests do not give a clear answer. MRI is done more commonly than other tests to
check for certain bone and joint problems.