X-rays are a type of radiation called electromagnetic waves that create images of the inside of the body. These images show the parts of the body in different shades of black and white, as different tissues absorb different amounts of radiation. The calcium in bones absorbs X-rays the most, so bones appear white, while fat and other soft tissues absorb less and look gray. Air absorbs the least, so the lungs look black.
X-rays are used in a variety of medical imaging tests and procedures, such as detecting fractured bones, mammography for breast cancer screening, and traditional X-ray imaging for viewing bones, bone fractures, calcium-dense tissues, dental x-rays, and the chest. Current mammography has advanced to include 3D images that show the entire breast to help increase the likelihood of early detection of breast cancer. If an X-ray is taken to determine the extent of a bone injury and reveals a fracture, the bone will need to be fixed.The FDA's Center for Devices and Radiological Health (CDRH) regulates the manufacture of electronic products that emit radiation, such as CT scanners and X-ray machines. States regulate the use of X-ray equipment.
The lifetime risk of developing cancer is more significant for a person who is exposed to radiation at a younger age than for a person who has x-rays taken when they are older. Contrasts are administered before radiography, with the exception of intravenous contrast dye which allows a constant flow of material to be administered. Extensive information is available about the types of X-ray imaging exams, the diseases and conditions in which different types of X-ray images are used, and about the risks and benefits of X-ray imaging.A center can use its quality control (QA) program to optimize the radiation dose for each type of radiographic examination, procedure, and medical imaging task it performs. Facility quality assurance and staff training, with a focus on radiation safety, are crucial for applying radiation protection principles to X-ray imaging exams.
The FDA worked with the Environmental Protection Agency and the federal Interagency Steering Committee on Radiation Standards (ISCORS) to develop and publish the Federal Radiation Protection Guide for Diagnostic and Interventional X-ray Procedures (FGR-1) on the medical use of radiation in federal centers.The total exposure to X-ray radiation depends on the duration of the fluoroscopic procedure and how often the X-ray beam is used. For example, a chest X-ray emits a radiation dose similar to the amount of radiation you're naturally exposed to from the environment for 10 days. An X-ray machine creates a burst of X-rays that pass through the breast and reach a detector located on the other side. The contrast media used during X-ray procedures may carry some minor risks, especially for people who have asthma or other conditions.
