X-ray

Alternative names: Radiograph

X-rays are the most common diagnostic imaging technique.  Although an X-ray does not show as much detail as more advanced imaging techniques, it is usually taken first so that the doctor can get some idea about what is happening inside your body.

Function; Why it is Recommended

The X-ray machine briefly emits electromagnetic radiation, which then passes through the body.  Some of this radiation is blocked by your body, and some passes through it to create an image of your internal structure on the film.  Harder structures (such as bones or tumors) block more radiation and show up white in the final X-ray image; empty cavities (such as the lungs) block little radiation and show up as darker areas.

Multiple X-rays are often taken from different angles, or for comparison with uninjured areas of the body.

X-rays can detect many problems, including:

• Heart disease: X-rays don't detect heart disease as such, but the heart enlargement that frequently occurs.
• Lung disease/infection: Tuberculosis and pneumonia are prime examples.
• Bone fractures: The doctor can easily determine whether there is a fracture, and whether it is a simple or compound fracture.
• Osteoporosis: X-rays can be used to measure bone density and, over time, determine how fast it is changing.
• Arthritis: By comparing X-ray images taken over the years, the development of arthritis can be monitored.  Worn cartilage in the joints, and bones touching other bones, is indicative of osteoarthritis.
• Bone cancer
• Breast cancer: Using mammography, tumors in the breast can often be identified before they can be felt through physical examination.
• Blocked blood vessels: Blood can not be seen in X-ray images, unless the patient is injected with a substance that makes it show up.
• Hidden tooth decay
• Swallowed items

Chest X-rays are one of the most commonly ordered imaging tests.

Instructions

The part of the body that needs to be X-rayed is positioned between the X-ray emitter and photographic film.  It is important to remain still during the procedure, not even breathing when the chest area is targeted.  Barium sulfate or a dye is sometimes given in order to make certain objects stand out in the image.

Expected Outcome; Side-Effects

Dense objects such as bones and tumors can be identified relatively easily, as can less dense areas (soft tissue, breaks in bone.)

The level of radiation exposure from individual X-rays is not harmful, but special precautions should be taken for pregnant patients.  Lead shielding in the walls of the X-ray room is used to protect the attendants (they are present during thousands of X-rays), and lead shields are sometimes placed over certain parts of the patient's body that are not required to be in the image.