X-ray is a picture of your hand, wrist, arm, foot,
ankle, knee, hip, or leg. It is done to see whether a bone has been
fractured or a joint
dislocated. It is also used to check for an injury or
damage from conditions such as an infection,
arthritis, bone growths (tumors), or other bone
diseases, such as
X-rays are a form of
radiation, like light or radio waves, that are focused into a beam, much like a
flashlight beam. X-rays can pass through most objects, including the human
body. X-rays make a picture by striking a detector that either exposes a film
or sends the picture to a computer. Dense tissues in the body, such as bones,
block (absorb) many of the X-rays and look white on an X-ray picture. Less
dense tissues, such as muscles and organs, block fewer of the X-rays (more of
the X-rays pass through) and look like shades of gray on an X-ray. X-rays that
pass only through air, such as through the lungs, look black on the picture.
Why It Is Done
Extremity X-rays are done to:
- Find the cause of pain in an
- See if your bone is fractured or your joint is
- See if fluid has built up in the joint or around a
- See if your bones are positioned properly after treatment for
a fracture or dislocation, such as after placing a cast or splint on an arm or
leg. An X-ray also may be done after a doctor places a device such as a pin or
an artificial joint in a bone.
- Find changes in your bones caused by
conditions such as an infection, arthritis, bone growths (tumors), osteoarthritis of the hip , osteoarthritis of the knee , or other
- Find foreign
objects such as pieces of glass or metal.
- Check to see if a child's
bones are growing normally.
- See if your bones and joints are in the
correct position after joint replacement surgery.
How To Prepare
Before the X-ray test, tell your
doctor if you are or might be pregnant. Pregnancy and the risk of radiation
exposure to your unborn baby (fetus) must be considered. The risk of
damage from the X-rays is usually very low compared with the potential benefits
of the test. If an extremity X-ray is absolutely necessary, a lead apron will
be placed over your abdomen to help shield your baby from exposure to the
Talk to your
doctor about any concerns you have regarding the need for the test, its risks,
how it will be done, or what the results will mean. To help you understand the
importance of this test, fill out the
medical test information form(What is a PDF document?).
You don't need to do anything else before you have this