X-rays are beams of energy that create shadows of internal structures when they pass through the body. The beams pass through skin and muscle, but are blocked by the bones and teeth. Their shadows are captured on photographic film and called x-rays. Examiners sometimes inject substances that give contrast to soft tissues. These materials include barium, dyes, and radioactive mixtures.
X-rays are fairly safe, but excessive use can pose some health risks. The effects of radiation from repeated x-rays collect over a lifetime. Too much exposure can lead to serious illness. These include blood disorders, cataracts, skin problems, and cancer. However, doctors are aware of these risks. They consider the person's total exposure before x-ray tests.
A variety of x-ray tests exist. Most people have had dental x-rays. These are extremely low-dose tests that pose almost no risk. Chest x-rays are another common test. X-rays are often taken of broken bones. Mammography is a test recommended for early detection of breast cancer. These tests use extremely short bursts of x-ray beams and pose little risk. Other x-ray tests include fluoroscopy, and CT scans.
Fluoroscopy produces a moving x-ray image of internal organs. A constant stream of x-rays passes through the person. This casts shadows of internal structures onto a fluorescent screen. Fluoroscopy reveals less detail than a standard still x-ray. It also exposes the person to somewhat more radiation. For these reasons, radiologists use fluoroscopy only when they need to see movement of internal structures.
A CT scan produces an image of a cross-section of the body. It uses x-ray beams, but provides much more detail than a standard x-ray film. CT is short for computerized tomography. The procedure allows x-rays to be taken all around the body while lying inside a long x-ray unit or tube. It sends many beams though the same area. The beams are detected on the other side of the body and analyzed by computer. The computer translates the image to a film that contrasts various tissue types in different shades. CT scans use less radiation than regular x-ray films. Therefore, they are relatively safe.
If you have questions or concerns about the safety of x-rays, ask your doctor to explain the benefits and risks of procedures.
Article #5240
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