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