X-Ray?
X-rays are a form of electromagnetic radiation, just like visible light. In a health care setting, a machines sends are individual x-ray particles, called photons. These particles pass through the body. A computer or special film is used to record the images that are created.
Discovered by...
X-rays were first observed and documented in 1895 by Wilhelm Conrad Roentgen, a German scientist who found them quite by accident when experimenting with electron beams in a gas discharge tube.
Roentgen noticed that a fluorescent screen in his lab started to glow when the electron beam was turned on. This response in itself wasn't so surprising -- fluorescent material normally glows in reaction to electromagnetic radiation -- but Roentgen's tube was surrounded by heavy black cardboard. Roentgen assumed this would have blocked most of the radiation.
He placed various objects between the tube and the screen, and the screen still glowed. A week later, he took an X-ray photograph of his wife's hand which clearly revealed her wedding ring and her bones. The photograph electrified the general public and aroused great scientific interest in the new form of radiation. Roentgen called it "X" to indicate it was an unknown type of radiation. The name stuck, although (over Roentgen's objections), many of his colleagues suggested calling them Roentgen rays. They are still occasionally referred to as Roentgen rays in German-speaking countries.
Roentgen's remarkable discovery precipitated one of the most important medical advancements in human history. X-ray technology lets doctors see straight through human tissue to examine broken bones, cavities and swallowed objects with extraordinary ease. Modified X-ray procedures can be used to examine softer tissue, such as the lungs, blood vessels or the intestines.
Hummm...
Structures that are dense (such as bone) will block most of the x-ray particles, and will appear white. Metal and contrast media (special dye used to highlight areas of the body) will also appear white. Structures containing air will be black, and muscle, fat, and fluid will appear as shades of gray.
For most conventional x-rays, the risk of cancer or defects due to damaged ovarian cells or sperm cells is very low. Most experts feel that this low risk is largely outweighed by the benefits of information gained from appropriate imaging. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image.
Young children and fetuses are more sensitive to the risks of x-rays. Women should tell health care providers if they think they are pregnant.
Source:
http://www.nlm.nih.gov/
http://health.howstuffworks.com/
http://science.hq.nasa.gov/
Content
X-Ray already 115 years old?!?
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runingsmansev
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Biology jreng...haha,
Health,
School subject,
Teknologi Informasi dan Komunikasi





2 komentar:
hohoo.. nice info
here is a place with a lot of information
hmm nice info , we hace to give thanks for Wilhelm Conrad Roentgen
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