They are packets of energy that have no charge or mass weight. These packets of energy are known as photons. Because X-rays and gamma rays have the same properties and health effects, they are grouped together in this document. Both x-rays and gamma rays are forms of high-frequency ionizing radiation , which means they have enough energy to remove an electron from ionize an atom or molecule. Ionized molecules are unstable and quickly undergo chemical changes.
Sometimes this causes the cell to die, but sometimes it can lead to cancer later on. The amount of damage caused in the cell is related to the dose of radiation it receives. The damage takes place in only a fraction of a second, but other changes such as the beginning of cancer may take years to develop. Some types of ultraviolet UV radiation are also ionizing. These structures are displayed in shades of gray on a radiograph.
Listed below are examples of examinations and procedures that use x-ray technology to either diagnose or treat disease:. X-ray radiography: Detects bone fractures, certain tumors and other abnormal masses, pneumonia, some types of injuries, calcifications, foreign objects, dental problems, etc. Mammography : A radiograph of the breast that is used for cancer detection and diagnosis. Tumors tend to appear as regular or irregular-shaped masses that are somewhat brighter than the background on the radiograph i.
Mammograms can also detect tiny bits of calcium, called microcalcifications, which show up as very bright specks on a mammogram. While usually benign, microcalcifications may occasionally indicate the presence of a specific type of cancer. CT computed tomography : Combines traditional x-ray technology with computer processing to generate a series of cross-sectional images of the body that can later be combined to form a three-dimensional x-ray image.
CT images are more detailed than plain radiographs and give doctors the ability to view structures within the body from many different angles. Fluoroscopy: Uses x-rays and a fluorescent screen to obtain real-time images of movement within the body or to view diagnostic processes, such as following the path of an injected or swallowed contrast agent. For example, fluoroscopy is used to view the movement of the beating heart, and, with the aid of radiographic contrast agents, to view blood flow to the heart muscle as well as through blood vessels and organs.
This technology is also used with a radiographic contrast agent to guide an internally threaded catheter during cardiac angioplasty, which is a minimally invasive procedure for opening clogged arteries that supply blood to the heart. A fan-shaped beam of X-rays passes through the patient onto a number of detectors.
This procedure uses the highest dose of X-rays because a large number of images are taken in one sitting. X-rays can cause mutations in our DNA and, therefore, might lead to cancer later in life.
However, the benefits of X-ray technology far outweigh the potential negative consequences of using them. It is estimated that 0. Some scientists expect this level to rise in parallel with the increased use of CT scans in medical procedures.
At least 62 million CT scans were carried out in America in According to one study, by the age of 75 years, X-rays will increase the risk of cancer by 0. In other words, the risks are minimal compared to the benefits of medical imaging. Each procedure has a different associated risk that depends on the type of X-ray and the part of the body being imaged.
The list below shows some of the more common imaging procedures and compares the radiation dose to the normal background radiation that all people encounter on a daily basis. These radiation figures are for adults. Children are more susceptible to the radioactive effects of X-rays. While X-rays are linked to a slightly increased risk of cancer, there is an extremely low risk of short-term side effects.
Exposure to high radiation levels can have a range of effects, such as vomiting, bleeding, fainting, hair loss , and the loss of skin and hair. However, X-rays provide such a low dose of radiation that they are not believed to cause any immediate health problems. The fact that X-rays have been used in medicine for such a significant length of time shows how beneficial they are considered to be.
Although an X-ray alone is not always sufficient to diagnose a disease or condition, they are an essential part of the diagnostic process. An average CT scan might raise the chance of fatal cancer by 1 in 2, This figure pales in comparison to the natural incidence of fatal cancer in the US of 1 in 5.
Note: we are unable to answer specific questions or offer individual medical advice or opinions. Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Please contact your physician with specific medical questions or for a referral to a radiologist or other physician.
To locate a medical imaging or radiation oncology provider in your community, you can search the ACR-accredited facilities database. This website does not provide cost information. The costs for specific medical imaging tests, treatments and procedures may vary by geographic region.
Web page review process: This Web page is reviewed regularly by a physician with expertise in the medical area presented and is further reviewed by committees from the Radiological Society of North America RSNA and the American College of Radiology ACR , comprising physicians with expertise in several radiologic areas.
Outside links: For the convenience of our users, RadiologyInfo. Toggle navigation. What are x-rays and what do they do? Measuring radiation dosage Naturally occurring "background" radiation Effective radiation dose in adults Benefit versus risk.
Measuring radiation dosage When radiation passes through the body, some of it is absorbed. Naturally occurring "background" radiation We are exposed to natural sources of radiation all the time.
Effective radiation dose in adults Here are some approximate comparisons of background radiation and effective radiation dose in adults for several radiology procedures described on this website. X-ray Less than 0. Benefit versus risk The risk associated with medical imaging procedures refers to possible long-term or short-term side effects. Send us your feedback Did you find the information you were looking for?
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