An X-ray uses a radioactive beam to take pictures of bone. The beam is projected through your body onto a special film, just like a camera.
An X-ray is good at showing bone. An X-ray is helpful if your doctor suspects a fracture of the spine, an infection, or a tumor. Doctors have used X-rays for over 100 years to check bone alignment and to see whether certain shadows appear to be out of alignment. This can give your doctor a clue about the health of the soft tissues around your spine. If your doctor thinks your problem may be from degeneration of the spine, X-rays can be used to see whether the spaces between your vertebrae have decreased, whether there are bone spurs, or hypertrophy (enlargement) of the facet joints.
Having an X-ray is much like having your photograph taken. It is a quick and painless procedure. You will be asked to lie very still on a table or stand very still and hold certain positions while pictures are taken of your spine. Sometimes X-rays are taken while you are in different positions. For example, an X-ray may be taken while you bend forward (which is called flexion), and another while you straighten your spine (which is called extension). This is called a "flexion-extension" view of the spine. These X-rays are compared to see whether there is extra movement between your vertebrae, which would indicate a condition called segmental instability.
X-rays are not good at showing soft tissues including your spinal nerves, intervertebral discs, and ligaments. Today many tests can show the soft tissues much clearer, so doctors do not always have to rely on X-rays. However, X-rays provide a good starting point in evaluating the spine.
X-rays use radiation, which in large doses can increase the risks of cancer. The vast majority of patients who get X-rays will never get enough radiation to worry about cancer. Only patients who must have large numbers of X-rays - hundreds over many years - need to worry about this risk. Children, and young adults who plan to have children, should be protected from radiation exposure to the testicles and ovaries. The radiation may damage the sperm and eggs. The person performing the X-ray will usually protect these areas for you by shielding them with a lead apron or lead blanket.