X-rays, Radiation That Helps in Examining Your Body - Essay Example

X-ray discovery in 1895 was one major step in the field of science and medicine. Since its discovery, numerous experiments have been conducted to further establish and unravel the mystery behind various effects of X-rays which included skin inflammations, sores in the skin and sometimes death upon exposure. Numerous experiments were also conducted in a bid to investigate the X-rays’ properties. This effect of X-ray has been put to use in the field of medicine and currently it provides solution to many health issues. Having a very short wave length and high frequency, X-rays have a high penetration effect. They are produced when high speed electrons produced by cathode (filament) are suddenly brought to a stop by a metal target (anode) resulting to some of their kinetic energy being converted to X-rays (Hendee, 1995). In addition to this, X-rays are also produced naturally by natural sources such as radioactive isotopes. X-rays used in medicine are artificially produced by X-ray tubes. X-rays applications in medicine basically uses the concept of x-ray interaction with matter. This x-ray interaction is important in medical diagnosis (Sprawls, 1995). There are two major interaction processes of x-rays; scattering and photoelectric absorption (Carlsson & Carlsson, 1996). With these two processes, the x-ray photon is either absorbed or changes its energy form and direction. Nonetheless, a small percentage of x-ray photons pass through matter without interacting with electrons of the atoms that make up that matter. X-ray penetration will occur if the x-ray photons have enough energy to go through the atomic structure of matter (Goaz & Pharaoh, No Date). X-ray photon absorption means that the photons are completely eliminated from the x-ray beam and they no-longer exist (Sprawls, 1995). Therefore, the x-ray photon loses all its energy to the electrons of the atoms which makes up the matter. Scattering on the other hand implies that the x-ray photon loses part of its energy and changes direction (Sprawls, 1995). There are two forms of scattering processes which can occur to an x-ray photon; Compton (inelastic) and elastic (coherent) scattering. With Compton scattering, there is partial loss of energy and the x-ray photon produced as a result changes its direction (Sprawls, 1995). The amount of energy present in the incident x-ray photon will determine the angle in which the emerging photon will be scattered (Goaz & Pharaoh, No Date). Additionally, the electron density varies directly with the probability of inelastic scattering occurring (Goaz & Pharaoh, No Date). Scattering can also occur without loss of energy. This scattering is referred to as coherent scattering (Seibert & Boone, 2005). Since there is minimal loss of energy, most photons are scattered frontwards and with a small angle (Seibert & Boone, 2005). There is minimal scattering in soft tissues. Figure 1: Three possible fates which can occur to x-ray photons when they enter human body. Source: (Sprawls, 1995) Applications of X-ray Absorption in Medicine The application of x-ray absorption in the field of medicine has developed extensively since the discovery of x-rays. In the United States alone, over 300 million x-ray medical examinations are done every year (Hendee, 1995). X-rays have been used in medical diagnosis and treatment therapy. In the past, diagnosis and therapy were perceived to be different. However, the boundary between the two seems to have disappeared and currently, the two have been integrated together (Hendee, 1995). There are numerous applications of x-rays in medicine today. Diagnostic Radiography Radiography is defined as that process of production of images of the body structures by use of X-rays (O’Sullivan, 2009). Radiography is normally used in the diagnosis of problems in chest, broken bones and dental structure. This imaging technique was initiated by Roentgen who experimented with his wife’s hand (Hendee, 1995). In his experiment, Roentgen was able to note that x-ray beam projected on his wife’s hand produced the skeleton image of the hand with a ring on. This experiment yielded what is today referred to as radiology and it is an important component of modern day medicine. In x-ray imaging or radiology, the patient is placed between an x-ray detector (film) and x-ray tube. The images produced in the films are as a result of x-ray photons which penetrate the body structure. X-ray photon interaction with the body and its penetration is dependent on the density of the tissues in the body. Soft tissues are easily penetrated by x-ray photons when compared to high density tissues such as the skeleton. X-ray radiography is a common phenomenon currently and it is estimated that 70% of U.S residents get at least one x-ray radiology in a year (Kane, 2009). X-ray radiography provides a cost effective glimpse of the inner body of human beings and has provided a solution to one major disadvantage of ultrasound of failing to penetrate other regions of the body. Radiograph images are simply the shadows of body parts which absorb x-ray photons (Kane, 2009). In fact, the image formed is basically a shadowgraph. Those x-ray photons which do not interact with electrons of the atoms of the body penetrate the body and are detected on the opposite side by the film. Films produce static images. However, fluoroscopy is an alternative to x-ray image films and they produce moving images (Hendee, 1995). As earlier mentioned, x-ray photons interact with electrons of atoms making up a body while those photons having sufficient energy penetrate the body. The x-ray photons which penetrate the body are detected by the x-ray detector film forming images. However, some photons are absorbed while others are scattered. Scattered x-ray photons may penetrate the body. For instance, in a dental x-ray imaging, 30% of those x-ray photons scattered in that process penetrate the patient’s body (Goaz & Pharaoh, No date). These photons which penetrate after being scattered have both advantages and disadvantages. It allows for the escape of energy from the tissues (Goaz & Pharaoh, No date). However, the disadvantage is that they are detected by the film and causes film fogging. They therefore interfere with the information conveyed by the film (Hendee, 1995). In the case of fracture detection, x-rays are projected on the affected region of the bone. The x-ray photons are attenuated depending on the nature of tissues making up that region. High density tissues attenuates more x-ray photons compared to softer tissues. The density of calcium in the bones attenuates all the x-ray photons thus blocking all the x-rays from reaching the film and darkening it (Linton,1995). Those regions of the film which are not elucidated by the x-ray beam retain their grayish colour. Bones have a fluid inside which causes lesser attenuation to x-ray photons (Fessler, 2009). A fracture in a bone can therefore be focused clearly on the screen because of lesser attenuation by the bone fluid in that section. Fluids generally attenuates lesser x-rays when compared to solid matter. Radiography can therefore be performed on the stomach and chest region and it can provide a glimpse of their structures. Stomach and liver are for instance fluid filled and therefore attenuate lesser x-rays. More x-ray photons can therefore penetrate the stomach and the liver. The image structures of the stomach and liver will appear grayish on the film because they allow more x-rays to penetrate (Linton,1995). Lungs on the other hand have air spaces inside. These air spaces can be penetrated by more x-ray photons thus they are nearly black on the film (Linton,1995). Additionally, cancer growths cause irregular shadowing of the image film (Linton,1995). Such abnormalities may require sophisticated viewing and a normal physician may not be able to note such irregularities. Generally, all the body parts have different densities. Therefore, the colouration on the film will vary from one part of the body to another. Abnormalities resulting from injuries and infections can therefore be easily noted on the film by a trained professional. Computerized Tomography (CT) Computed tomography was a major advancement to x-ray imaging technology which allowed for the production a series of images having detailed information (National Cancer Institute, 2013). It provided a solution to the problem of the planar x-ray images through the production of three dimensional images. Each organ subjected to a CT scan is displayed in form of thin slices which can be analysed individually (National Cancer Institute, 2013). Computed tomography is advantageous over the normal x-ray imaging because it provides detailed information that can guide treatment. Additionally, it is capable of detecting circulatory system diseases (National Cancer Institute, 2013). Additionally, unlike the normal x-ray imaging, CT scan can provide information on the stages of cancer growth which is crucial in the determination of required dosage treatment. Angiography It is a special x-ray imaging technique that is diagnose problems related to blood vessels. Angiography technologies such as the CT, x-ray with catheters and magnetic resonance imaging. It involves injection of a contrasting fluid to the blood system of the human beings which allows for the visualization of blood vessels (Linton, 1995). Blockages in the vessels and other vessel related problems can be easily visualized on the images produced by the CT scan. X-ray Therapy X-rays have also been of great use in the treatment of different diseases. The use of x-rays in treatment came immediately after the discovery of x-rays (Orton, 1995). The effect of x-rays on living tissues was part of a series of experiments which were conducted immediately after the discovery of x-rays. Some of the results of these series of experiments indicated that lower doses of x-rays had various effects on tissues. For instance, it was discovered that x-rays had an effect on skin diseases, sores dried after exposure to x-rays of low energies, open cancerous growths appeared to shrink after exposure to low energy x-rays and those who were suffering from arthritis reported a relief from pains (Linton, 1995). These experiments also indicated that high energy x-rays killed more cancer cells while leaving the normal ones (Linton, 1995). The rapid cellular division of cancer cells was a reason given for their susceptibility to radiations (Linton, 1995). Normal cells are capable of withstanding the effects of x-rays because of their slower growth. Nonetheless, there were some negative effects which were noted on those who were constantly exposed to x-ray radiations. Effects such as inflammations on the skin, abnormalities in the blood and emergence of cancerous growths were a major point of concern (Linton, 1995). Researchers have discovered that these negative effects can be reduced through the administration of proper doses of x-ray treatment which will not have an effect on the normal cells. Therefore, the success of an x-ray therapy will depend on the plan of x-ray dose administration that will ensure that cancer cells are killed without destruction of normal cells in the vicinity of that affected region (Linton, 1995; Hendee, 1995). Therefore, x-ray imaging may be required to delineate the margins of the cancerous growth (Hendee, 1995). Use of CT scan may help to establish the stage of growth of the cancerous growth. The information provided by the CT scan can be used to determine the x-ray dose to be administered to the cancerous growth. References Carlsson, C. & Carlsson, G. (1996). Basic Physics of X-ray imaging (2nd ed). Linkoping University: Department of Radiation Physics. Delchar, T. (1997). Physics in Medical diagnosis. New York: Springer science and Business media. Fessler, J. (2009).Physics of Projection radiography.[Online]. Available from: http://web.eecs.umich.edu/~fessler/course/516/l/c3-phys.pdf (Accessed on 10th May 2015) Goaz & Pharaoh. (No Date). Production of X-rays and Interactions of X-rays with Matter. 11-20. [Online]. Available from: http://www.columbia.edu/itc/hs/dental/sophs/material/production_xrays.pdf. (Accessed on 08th May 2015) Hendee, W. R. (1995). X-rays in Medicine. Physics Today, 48(11): 51-56. Kane, A. (2009). Introduction to Physics in Modern Medicine (2nd Ed). New York: Taylor and Francis. Linton, O. W. (1995). Medical applications of X-rays. Beam Line, 25(2): 25-34. National Cancer Institute. (2013). Computed Tomography (CT) Scans and Cancer. [Online]. Available from: http://www.cancer.gov/cancertopics/diagnosis-staging/ct-scans-fact- sheet (Accessed on 9th May 2015) O’Sullivan, B. (2009). Plain Radiography/X-rays. [Online]. Available from: http://www.insideradiology.com.au/pages/view.php?T_id=24#.VU5DTpNQ1_k (Accessed on 8th May 2015). Orton, C. G. (1995). Uses of Therapeutic X-Rays in Medicine. Health physics, 69(5): 662- 676. Seibert, A. & Boone, J. (2005). X-ray Imaging Physics for Nuclear Medicine Technologists. Part 2: X-ray Interactions and Image Formation. Journal of Nuclear Medicine Technology, 33 (1): 3-18. Sprawls, P. (1995). Interaction of Radiation with Matter In Physical principles of Medical Imaging (2nd Ed). Medical Physics Publishers. [Online]. Available from: http://www.sprawls.org/ppmi2/INTERACT/. (Accessed on 8th May 2015) Read More

Figure 1: Three possible fates which can occur to x-ray photons when they enter human body. Source: (Sprawls, 1995) Applications of X-ray Absorption in Medicine The application of x-ray absorption in the field of medicine has developed extensively since the discovery of x-rays. In the United States alone, over 300 million x-ray medical examinations are done every year (Hendee, 1995). X-rays have been used in medical diagnosis and treatment therapy. In the past, diagnosis and therapy were perceived to be different.

However, the boundary between the two seems to have disappeared and currently, the two have been integrated together (Hendee, 1995). There are numerous applications of x-rays in medicine today. Diagnostic Radiography Radiography is defined as that process of production of images of the body structures by use of X-rays (O’Sullivan, 2009). Radiography is normally used in the diagnosis of problems in chest, broken bones and dental structure. This imaging technique was initiated by Roentgen who experimented with his wife’s hand (Hendee, 1995).

In his experiment, Roentgen was able to note that x-ray beam projected on his wife’s hand produced the skeleton image of the hand with a ring on. This experiment yielded what is today referred to as radiology and it is an important component of modern day medicine. In x-ray imaging or radiology, the patient is placed between an x-ray detector (film) and x-ray tube. The images produced in the films are as a result of x-ray photons which penetrate the body structure. X-ray photon interaction with the body and its penetration is dependent on the density of the tissues in the body.

Soft tissues are easily penetrated by x-ray photons when compared to high density tissues such as the skeleton. X-ray radiography is a common phenomenon currently and it is estimated that 70% of U.S residents get at least one x-ray radiology in a year (Kane, 2009). X-ray radiography provides a cost effective glimpse of the inner body of human beings and has provided a solution to one major disadvantage of ultrasound of failing to penetrate other regions of the body. Radiograph images are simply the shadows of body parts which absorb x-ray photons (Kane, 2009).

In fact, the image formed is basically a shadowgraph. Those x-ray photons which do not interact with electrons of the atoms of the body penetrate the body and are detected on the opposite side by the film. Films produce static images. However, fluoroscopy is an alternative to x-ray image films and they produce moving images (Hendee, 1995). As earlier mentioned, x-ray photons interact with electrons of atoms making up a body while those photons having sufficient energy penetrate the body. The x-ray photons which penetrate the body are detected by the x-ray detector film forming images.

However, some photons are absorbed while others are scattered. Scattered x-ray photons may penetrate the body. For instance, in a dental x-ray imaging, 30% of those x-ray photons scattered in that process penetrate the patient’s body (Goaz & Pharaoh, No date). These photons which penetrate after being scattered have both advantages and disadvantages. It allows for the escape of energy from the tissues (Goaz & Pharaoh, No date). However, the disadvantage is that they are detected by the film and causes film fogging.

They therefore interfere with the information conveyed by the film (Hendee, 1995). In the case of fracture detection, x-rays are projected on the affected region of the bone. The x-ray photons are attenuated depending on the nature of tissues making up that region. High density tissues attenuates more x-ray photons compared to softer tissues. The density of calcium in the bones attenuates all the x-ray photons thus blocking all the x-rays from reaching the film and darkening it (Linton,1995).

Those regions of the film which are not elucidated by the x-ray beam retain their grayish colour. Bones have a fluid inside which causes lesser attenuation to x-ray photons (Fessler, 2009).

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