X-rays are a form of electromagnetic radiation that can be passed through the body to project an image on either a piece of film or a digital detector. It is generally quick and painless to perform and is particularly useful for examining the bones and the lungs.
While often useful as a first line test, X-rays have limitations in the types of conditions that can be diagnosed. Small lung cancers for example, may not visible on a chest x-ray. The solid organs in the abdomen, brain and spinal cord are some parts of the body that cannot be seen on conventional x-rays. Newer imaging techniques such as ultrasound, CT and MRI scans were developed to overcome these limitations.