| X-rays use invisible electromagnetic energy beams to | | | | (blockage of the intestine), free air (from visceral |
| produce images of internal tissues, bones, and organs | | | | perforations) and free fluid (in ascites). |
| on film or digital media. Standard x-rays are performed | | | | In some cases, the use of X-rays is debatable, such |
| for many reasons, including diagnosing tumors or bone | | | | as gallstones (which are rarely radiopaque) or kidney |
| injuries. | | | | stones (which are often visible, but not always). Also, |
| X-rays are made by using external radiation to | | | | traditional plain X-rays pose very little use in the |
| produce images of the body, its organs, and other | | | | imaging of soft tissues such as the brain or muscle. |
| internal structures for diagnostic purposes. X-rays pass | | | | Imaging alternatives for soft tissues are computed |
| through body structures onto specially-treated plates | | | | axial tomography (CAT or CT scanning), magnetic |
| (similar to camera film) or digital media and a "negative" | | | | resonance imaging (MRI) or ultrasound. Since 2005, |
| type picture is made (the more solid a structure is, the | | | | X-rays are listed as a carcinogen by the U.S. |
| whiter it appears on the film). | | | | government. |
| When the body undergoes x-rays, different parts of | | | | Diagnostic x-rays are safe. But who hasnt wondered |
| the body allow varying amounts of the x-ray beams | | | | about them when undergoing a chest x-ray, |
| to pass through. The soft tissues in the body (such as | | | | mammogram, routine dental x-rays, or an x-ray for a |
| blood, skin, fat, and muscle) allow most of the x-ray to | | | | broken bone? |
| pass through and appear dark gray on the film or | | | | The safety of routine X-rays has been called into |
| digital media. A bone or a tumor, which is more dense | | | | question following the unexpected discovery that cells |
| than the soft tissues, allows few of the x-rays to pass | | | | exposed to low doses avoid or delay repairing |
| through and appears white on the x-ray. At a break in | | | | damaged DNA. |
| a bone, the x-ray beam passes through the broken | | | | Puzzlingly, cells given higher doses of X-rays were |
| area and appears as a dark line in the white bone. | | | | faster and more efficient at patching up any damage. |
| X-ray technology is used in other types of diagnostic | | | | But the German researchers who made the discovery |
| procedures, such as arteriograms, computed | | | | say it is not clear whether the sloppy repairs that |
| tomography (CT) scans, and fluoroscopy. | | | | follow low level exposure is a good or bad thing. |
| When medical X-rays are being produced, a thin | | | | Kai Rothkamm and Markus Brich, at the University of |
| metallic sheet is placed between the emitter and the | | | | Saarland in Homburg, acknowledge that unrepaired |
| target, effectively filtering out the lower energy (soft) | | | | breaks in DNA could well lead to cells becoming |
| X-rays. This is often placed close to the window of | | | | cancerous. But it is equally possible, they say, that the |
| the X-ray tube. The resultant X-ray is said to be hard. | | | | failure to repair low-level DNA damage has evolved as |
| Soft X-rays overlap the range of extreme ultraviolet. | | | | a safety measure. |
| The frequency of hard X-rays is higher than that of | | | | Other experts state that no scientific data indicate any |
| soft X-rays, and the wavelength is shorter. | | | | danger. In fact, there is evidence that low doses may |
| Hard X-rays overlap the range of "long"-wavelength | | | | actually reduce the chance of cancer. The question |
| (lower energy) gamma rays, however the distinction | | | | about the amount of radiation you receive is difficult |
| between the two terms depends on the source of the | | | | for x-ray technicians and doctors to answer because |
| radiation, not its wavelength; X-ray photons are | | | | very few x-ray units have an instrument to measure |
| generated by energetic electron processes, gamma | | | | the radiation to the patient. |
| rays by transitions within atomic nuclei. | | | | You may have heard that even the smallest amount |
| Since antigen's discovery that X-rays can identify bony | | | | of radiation may cause cancer. Based on this |
| structures, X-rays have been developed for their use | | | | unscientific assumption, the risk of causing a fatal |
| in medical imaging. Radiology is a specialized field of | | | | cancer from a chest x-ray is 10 times greater than the |
| medicine. Radiographers employ radiography and other | | | | risk of dying in a commercial airline flight. Or a CT scan |
| techniques for diagnostic imaging. Indeed, this is | | | | of the kidneys has a greater risk of inducing a fatal |
| probably the most common use of X-ray technology. | | | | cancer than a cigarette smoker has of dying from any |
| X-rays are especially useful in the detection of | | | | cancer. These statements produce unnecessary |
| pathology of the skeletal system, but are also useful | | | | worry. There is no data to show any risk from |
| for detecting some disease processes in soft tissue. | | | | diagnostic x-rays. |
| Some notable examples are the very common chest | | | | Lastly, radiation during pregnancy may lead to birth |
| X-ray, which can be used to identify lung diseases | | | | defects. Always tell your radiologist or physician if you |
| such as pneumonia, lung cancer or pulmonary edema, | | | | suspect you may be pregnant. |
| and the abdominal X-ray, which can detect ileus | | | | |