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Michael Smith
Mr. Barr
March 29, 2011
The Benefits of X- ray Technology
The X-ray was a monumental leap forward for technology and the medical fields, X-rays
have helped the medical community expand to the point that Radiologists can help to diagnose
diseases as well as give detailed information about the human body which was once only
dreamed about. X-rays are providing support for doctors today by helping prevent illnesses of
the human body. In addition, X-rays are also making it easier for doctors to treat people
effectively and efficiently. With each new discovery in the X-ray field, doctors are learning more
about the human anatomy than ever before.
The X-ray was discovered by Wilhelm Roentgen on September 8th, 1895. Roentgen was
in his lab investigating the properties of cathode rays when he discovered his X-ray. Roentgen
had decided to recreate the experiments of Lenard’s and Hertz's, which stated that cathode rays
had always penetrated the glass tube, which was unknown in the past. When Roentgen started his
experiment, Roentgen covered a glass tube with black cardboard, in a darkened room, when
Roentgen supplied the electric current he realized that he had forgotten to put a screen directly in
front of the tube. After powering up the electric current a greenish yellow glow appeared on a
piece cardboard, this was lying on a chair several feet away from the tube.
Startled by this Roentgen went over to the screen to find that the tube was glowing in the
shape of the letter “A”, which had been written earlier in liquid barium platocyanide by one of
his students. Amazed, Roentgen placed the screen several feet in front of the tube and tested it
again. Once again, the screen began to glow. To test his discovery again Roentgen placed a deck
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of cards and a two inch book between the tube and the screen. Roentgen then discovered the ray
could glow through the items that he had placed in front of the path of its path.
Roentgen then used as small wooden box containing metal weights, Roentgen was
surprised to find that rays did not go through the entire box. The box only cast a shadow of the
metal weights on the screen. For the next month Roentgen dedicated every free moment to
investigating his discovery. On reflection, Roentgen stated, "I didn't think, I investigated.”. In
December, Roentgen made another huge discovery: while holding a lead pipe near the ray, the
bones of Roentgen’s fingers were shadowed onto the screen. Unable to believe his eyes,
Roentgen decided to show his wife what had taken up his life these past few months, after some
explaining Roentgen’s wife agreed to assist her husband which resulted in the famous X-ray
image of her hand. Discovering and inventing the X-ray gave Roentgen recognition worldwide
and inspired other scientist to improve on his work (Miller).
The X-ray was just the start of a whole new generation of medical technology. Inside of
the tube where the X-ray is created and electron is heated and charged toward a metal target (see
figure 1). The high energy electrons interact with the atoms in the metal target. Sometimes the
electron comes very close to a nucleus in the target and is deviated by the magnetic reaction. In
this process, which is called bremsstrahlung (braking radiation), the electron looses energy and a
photon (X-ray) is emitted.
Figure 1 X-ray
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The energy of the emitted photon can take any value up to the maximum energy of an
incident electron. The energy from the electron can also cause one of the electrons to be knocked
out of place. Without the electron a new one from a higher energy replaces it.
The difference between binding energy and the characteristic of the material is emitted as
a monoenergetic photon. This is seen when the visible X-ray photon shows its characteristic Xray line in the energy spectrum. Charles Barkla observed these lines in 1908 and 1909 and was
given the 1917 Nobel Prize for this discovery. Barkla also noted to the fact that X-rays are
electromagnetic waves. This is because of the different properties of X-rays. This new idea
introduced a new way for X-ray to be applied in science and industry.
X-rays are frequently used by doctors in hospitals to do medical research. Max von Laue
was the brilliant scientist that brought up that X-rays are electromagnetic waves with shorter
wavelengths in the same sequence as they are between the atoms in a crystal, then the scattering
of the X-ray when it hits the atom reveals some of the unknown properties of the X-ray. This is
because of the intervention effects that could be observed when an X-ray hits the layers of an
atom in a crystal. This result is very similar to the interference of a ray of light hitting a gitter of
densely packed scratches.
When Rontgen first discovered the X-ray in 1895, he noted a nearby fluorescent screen
glowed when the current was being passed. When the current was switched off the screen, the
fluorescent screen stopped glowing. Rontgen attributed this effect to previously unknown rays
which, X being the symbol for an unknown quantity, he called X-rays. Scientists and doctors
now know these rays, light and radio waves are a form of electromagnetic radiation.
X-rays have high energy and short wavelength and are able to pass through tissue. On the
X-rays’ passage through the body, the denser tissues, such as the bones, will block more of the
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rays than the less dense tissues will, such as the lung. A special type of photographic film is used
to record X-ray pictures. The X-rays are converted into light and the more energy has reached
the recording system, the darker region of the film (Close).
Long after the X-ray was developed, doctors have discovered new ways to look into the
human body with the usage of X-rays. One such way is the CT scan. A CT (computerized
tomography) scanner is a special kind of X-ray machine. Instead of sending out a single X-ray
through your body as with ordinary X-rays, several beams are sent simultaneously from different
angles.
The X-rays from the beams are detected after the X-rays have passed through the body
and the strength is measured. Beams have passed through less dense tissue such as the lungs will
be stronger, whereas beams have passed through denser tissue such as bone will be weaker. A
computer can use this information to work out the relative density of the tissues examined.
Each set of measurements made by the scanner is, in effect, a cross-section through the
body. The computer processes the results, displaying them as a two-dimensional picture shown
on a monitor. The technique of CT scanning was developed by the British inventor Sir Godfrey
Hounsfield, who was awarded the Nobel Prize for his work in 1972.
CT scans are far more detailed than ordinary X-rays. The information from the twodimensional computer images can be reconstructed to produce three-dimensional images by
some modern CT scanners. This type of X-ray can be used to produce virtual images show what
a surgeon would see during an operation. CT scans have already allowed doctors to inspect the
inside of the body without having to operate or perform unpleasant examinations. CT scanning
has also proven invaluable in pinpointing tumors and planning treatment with radiotherapy.
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The CT scanner was originally designed to take pictures of the brain. Now CT scanning
is much more advanced and is used to taking pictures of virtually any part of the body. The
scanner is particularly good at testing for bleeding in the brain, for aneurysms (when the wall of
an artery swells up), brain tumors, and brain damage. CT scans can also find tumors and
abscesses throughout the body and is used to assess types of lung disease. In addition, the CT
scanner is used to look at internal injuries such as a torn kidney, spleen or liver; or bony injury,
particularly in the spine. CT scanning can also be used to guide biopsies and therapeutic pain
procedures (Munro).
Over the years the field of radiology has change very little. radiographers take an image
of the bone structure using a similar technique to the first users in the late 1800’s. The major
difference between then and now is that now doctors can take better photos with a more in-depth
look at insides of the human body.
The way that doctors develop the film has also changed dramatically using more
advanced technology. Technologies like computes have been made to digitally enhance the
quality and prevent the loss of the image. This technique is also helpful in the transportation of
the image for research purposes. These Technological improvements have made X-ray machines
smaller and easier to move from place to place.
The use of linear accelerators provide a means of generating extremely short wavelength,
highly penetrating radiation, a concept dreamed of only a few short years ago. While the process
has changed little, technology has evolved allowing radiography tube widely used in numerous
areas of inspection. Radiography has seen expanded usage in industry to inspect not only welds
and castings, but to radio graphically inspect items such as airbags and canned food products.
Radiography has found use in metallurgical material identification and security systems
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at airports and other facilities. Although many of the methods and techniques developed over a
century ago remain in use, computers are slowly becoming a part of radiographic inspection. The
future of radiography will most likely see many changes. As noted earlier, companies are
performing many inspections without the aid of film.
Radiographers of the future will capture images in digitized form and e-mail the images
to the customer when the inspection has been completed. Film evaluation will likely be left to
computers. Inspectors may capture a digitized image, feed them into a computer and wait for a
printout of the image with a accept or reject report.
Systems will be able to scan a part and present a three-dimensional image to the
radiographer, helping he or she locate the defect within that part. Inspectors in the future will be
able to peel away layer after layer of a part to evaluate the material in much greater detail. Color
images, much like computer generated ultrasonic C-scans of today, will make interpretation of
indications much more reliable and less time consuming (Larson).
The X-ray has revolutionized the medical field by allowing doctors to look into the
human body without surgery. X-rays have made it so doctors can look at organs and study the
internal body parts for research. Doctors can have a better understanding show the human
anatomy works by viewing different types of X-rays. With the advances X-ray’s have provided,
the mysteries of the human body have become clearer.
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Works Cited
Callan, J. J. (1980). Radiography in Modern Industry. Retrieved January 1, 2010, from Kodak:
http://www.kodak.com/eknec/documents/87/0900688a802b3c87/Radiography-in-Modern-Industry.pdf
Close, F. (2001, May 15). //Nobel Prize.Org//. Retrieved August 24, 2010, from Noble Web AB:
http://nobelprize.org/educational/physics/x-rays/
Larson, B. (2001). NDT Resource Center. Retrieved August 24, 2010, from: http://www.ndt-ed.org/index_flash.htm
Miller, A. (2003, April 14). //The History of the X-Ray//. Retrieved August 24, 2010, from Mary Washington
College: http://www.umw.edu/hisa/resources/Student%20Projects/Amy%20Miller%20--%20XRay/students.mwc.edu/_amill4gn/XRAY/PAGES/invent.html
Munro, A. J. (2005, May 10). NetDoctor. Retrieved January 1, from:
http://www.netdoctor.co.uk/health_advice/examinations/x-ray.htm