In this report I will start by exploring Essay Example for Free

In this announce I will lift off by exploring EssayIn this report I will start by exploring the history of the Computerised mental realizery (CT) s sackner and the technological advances which have make this type of medical imaging one of the most booming in its field. In addition, I will give a power pointed explanation of the physics utilize to generate and manipulate a triple-dimensional image. These images argon utilisationd by physicians to diagnose cancers and vascular diseases or identify other injuries wi reduce the skeletal system, which can cause millions of deaths for each one year. This argona of research has been elect because I plan to enter the world of medicine in the next academic year.Medicine is invariably changing and developing. Cost containment and limitations reimbursed for broad(prenominal)-tech studies such as CT and Magnetic Resonance imagining (magnetic resonance imaging) argon breach of the future for the health c ar system. For CT to g row, or at least survive, it must provide to a greater extent information than other imaging modalities in a cost-effective, time-efficient manner and at this present time it is open to achieve its aim. History Computed Tomography (CT) imaging is likewise known as CAT scanning (Computed axile Tomography). Tomography is from the Greek words tomos meaning slice and graphia meaning describing.The first CT scanner was invented in Britain by the EMI Medical Laboratories in 1973 and was designed by the engineer Godfrey N Hounsfield. Hounsfield was afterwards awarded the Nobel Peace dirty money for his contri onlyions to medicine and science. material body 1. 0 (below left) show the first ever CT scanner produced, with its designer Hounsfield raise E. (1993) and Imaginis. com read that the first clinical CT scanners were installed between 1974 and 1976. The original systems were dedicated to head imaging only, but whole carcass systems with larger longanimous openings became avai lable in 1976.CT became widely available by about 1980. concord to Imaginis. com, at this present time there are approximately 6,000 CT scanners in the United States and about 30,000 worldwide. However, it should be noted that many third-world counties do not have the financial aptitude to purchase CT scanners and as a turn up do not posses them. The first consignment of CT scanners developed by the EMI took several hours to acquire the data for a single scan. In addition, it would take days to reconstruct a single image from this raw data.Bell J.(2006), suggest that modern CT scanners can collect up to 4 slices of data in about 350ms and reconstruct a 512 x 512 hyaloplasm from millions of data in less than a second. Since its development 36 years ago CT has made advances in speed, patient comfort and resolution . A bigger volume can be scanned in less time and artefacts can be reduced as faster scans can preclude faults ca apply from patient motion. Another advance took plac e in 1987. Bushong C. S (2004) suggests that, in the original CT scanners the roentgenogram causality was transferred to the roentgenogram metro by high voltage cable however modern CT scanners use the principle of slip ring.This is explained in much detail under advances. Figure 1. 1 (below right) shows what a modern CT scanner looks like. CT examinations are now quicker as well as world more patient-friendly. Much research has been underinterpreted in this field, which as a result has led to the development of high-resolution imaging for diagnostic purposes. In addition, the research has similarly reduced the risk of radiation by be able to provide good images at the lowest possible roentgen ray dose. Principles and Components of CT CT scanners are ground on the x-ray principle x-rays are high-energy electromagnetic waves which are able to lead finished the body.Roberts P. D (1990) states, that as they are absorbed or attenuated at different levels, they are able to crea te a matrix of differing strength. In x-ray machines this matrix is registered on film, whereas in the grammatical case of CT the film is replaced by get wordors which measure the strength of x-ray. To understand how a CT scanner whole kit and caboodle in more detail, I shall start by looking at the equipment use. Firstly, we must analyse the grassroots components which make a CT scanner work. These are the gantry, operating console and a computer. Figure 1. 2 shows the order in which the information passes.Figure 1.2 shows only basic components other components will be explained later in the course of this report. Arguably, the most important part of a CT scanner is the gantry. Gantry According to promote E (1993) and Impactscan. org, the gantry consists of an x-ray source. Opposite the x-ray source, on the other side of the gantry, is an x-ray detector. During a scan a patient will lie on a table which slides into the effect of the gantry until the part of the body to be sca nned is between the x-ray source and detector. The x-ray machine and x-ray detector both rotate around the patients body, re primary(prenominal)ing opposite each other.As they rotate around, the x-ray machine emits thin circularizes of x-rays through the patients body and into the x-ray detector. Figure 1. 3 shows the wrong of a gantry. The detectors detect the strength of the x-ray beam that has passed through the body. The denser the tissues, the less x-rays pass through. The x-ray detectors feed this information into a computer as shown is Figure 1. 3. Different types of tissue with different densities show up in a picture on the computer monitor as different colours or shades of grey. Therefore, an image is created by the computer of a slice (cross- section) of a thin section of a body.Before pass on any further we must understand the physics behind this process. roentgenogram tube The X-ray tube inside the gantry (figure 1. 4) produces the X-ray beams by converting electrica l energy into an electromagnetic wave. Graham T. D (1996) and Bbc. co. uk/ deoxyribonucleic acid/h2g2 suggest that, this is achieved by accelerating electrons from an electrically negative cathode towards a positive anode. As the electrons hit the target they are decelerated quickly, causing them to lose energy which is converted into heat energy and X-rays. The anode and cathode form a circuit which is finished by the flow of electrons through the vacuum of the tube.The basic layout of an X-ray tube is shown below (figure 1. 4). Figure 1. 4 shows that a high voltage is applied between the anode and the cathode. This very high potential is supplied by a high-voltage generator. The high voltage is the provider of the electrical energy needed for conversion and thus doing of X-ray beams. A generator is a device that converts mechanical energy into electrical energy. The process is based on the relationship between magnetism and electricity. In 1831, Faraday discovered that when a ma gnet is moved inside a coil of conducting wire, electrical current flows in the wire.Three-phase Generator Three-phase generators are typical of CT scanners. Ogborn J. (2001) and koehler. me. uk, state that this process can be thought of as three phase AC generators combined into one. The poles of the abiding rotating armature magnet swing past each of the non-permanent stator magnets. This induces an oscillating voltage across each of the three coils. Figure 1. 5 shows a three phase generator. As we can see from figure 1. 5, each of the three coils has a wire leading from it. These three wires join together to form the purple wire that leads to the purple terminal see from figure 1.5 As the three separate coils are pose 120i apart, the oscillations of each of these are 120i out phase. This fashion the purple (or neutral) wire can be quite thin since the different phases add up to approximately zero. The potential difference generated needs to be high high potential difference h as a number of advantages in CT scanners. High potential difference reduces trick up attenuation (greater penetration) allowing wider range of image (larger grey scale as bone is not merely snow-clad as on normal x-ray- (this will be explained later).In addition, the higher the radiation intensity at the detectors in the gantry, the better the information acquired. Gantry The Collimator In this section we shall look at the gantry (figure 1. 3) in more detail. Figure 1. 6 shows a diagrammatic representation of the inside of a gantry. According to Foster E (1993), inside the gantry is a beam restrictor called, collimator. Beam restrictors are lead obstacles placed close- operateting to the anode of the X-ray tube (figure 1. 4) and are used to control the width of the X-ray beam allowed to pass through the patient.Beam restrictors are needed as they keep patient exposure to a minimum and also reduce scattered rays. This is very important as X-rays are produced by a centre love on t he anode they are not all produced at the same point. In addition, restrictors also maintain beam width travelling through the patient, which as a result affects the image quality (stronger beam means better image). The most effective form of a beam restrictor is a collimator. This is situated in attend of the X-ray tube and consists of two sets of four sliding lead shutters which move independently to restrict the beam.The Filters By looking at figure 1. 6 we can see another apparatus positioned between the collimator and the X-ray tube. This is the filter and its job is to remove the long wavelength X-rays produced from the X-ray tube. Impactscan. org suggests that, the X-ray tube produces radiation which consists of long and little(a) wavelengths. However, the filter removes long wavelength radiation as this does not play a role in CT image formation, but increases patient dose. We know that long wavelength radiation is less energetic, and as a result passes through the body an d cannot be detected.Furthermore, a person who is very large may not fit into the opening of a conventional CT scanner or may be over the incubus limit for the moving table. This could possibly be the next technological advancement in CT scanners. Advantages The main advantage of CTs is that a short scan time of 600 milliseconds to a few seconds can be used for all anatomic part of the body. This is a big advantage especially for people who are claustrophobic. In addition, it is painless, non-invasive and accurate. As CT scans are fast and simple, in emergency cases they can reveal internal injuries and haemorrhage quickly enough to help save lives.Also, in this period of economic recession the CT has shown to be cost-effective imaging tool for a wide range of clinical problems. Comparing CT to its competitors the MRI scan, CT is less sensitive to patient movement and can be performed even if the patient has an enter medical device, unlike MRI. At the present time the CT scanner is superior to the MRI scanner. MRIs are bigger machines, with much more sensitive electronics in addition to requiring bigger support structures to operate them. To amount of money that all up- MRI machines cost more and this could be the underlying reason that CT are used more than MRI scans.Finally, a diagnosis determined by CT scanning may eliminate the need for exploratory surgery. Risks The main risk of CT is the chance of cancer from exposure to radiation. The radiation ionises the body cells which mutate when they replicate and form a tumour. However, the benefits of an accurate diagnosis outweigh the risks. In our recent acquire of ionisation radiation we have learned about the unit of Sievert. Radiologyinfo. org states that a radiation dose from this social occasion ranges from 2 to 5 mSV, which is approximately the same as the background radiation received in 4 years.The main risk of CT scanner is cancer however this is only if they are used excessively. seek for the impudent Scientist suggests that the risk is very small and the benefits greatly weight it. Summary In this report I started by looking at the history behind the CT scan and how this medical imaging has taken the science world by storm. I therefore explained the basic principles behind the scanner. As understanding of these principles grew, we were then led into the physics and a more in depth explanation. The different components of the CT were explained in detail such as the three-phase generator and how an x-ray tube works.This links in with our recent study of physics. During the report we were also able to understand how slip ring and thus helical scanning has proven to be a major advance is this field. Once again, the physics behind this was explained in some detail. The report cogitate by looking at the various applications, advantages and risks. The medical imaging world is constantly changing and better like any field of medicine. Companies are always trying to produce imaging machines which are faster, more accurate, more economical and present less risk to the patient.Therefore, the life span of the CT scanner could be limited with its competitors waiting to emerge in the background. The information in this report is very factual and accurate. I used a variety of sources to obtain the information. Most of the information in this coursework is attained from universities and radiology books. In addition, well-known articles were used from the monthly radiology magazine, Synergy as well as information from the New Scientist and Nature. Synergy is the biggest radiography magazine in the UK, which makes me believe that the information obtained it accurate.In addition, New Scientist and Nature are well established titles which more often than not provide accurate information. The websites I used are all recommended by The University of Hertfordshire to its undergraduates in radiography. This means they are also reliable sources of information. In addi tion, I also used a number of well recognised radiology books. By using different sources of information, I was able to eliminate any bias or inaccurate information provided in some sources. To congeries up, I believe the information provided is accurate and reliable.Bibliography Book References Allday J, Adams S (2000) travel Physics. Oxford University Press Ball J, more D. A (2006) Essential Physics for Radiographers. Blackwell Publishing Bushong C. S (2004) Radiologic Science for Technologist. Mosby Inc Duncan T, (1987) Physics A Textbook for Advanced Level Students. John Murray Elliott A, McCormick A (2004) Health Physics. Cambridge University Press Foster E (1993) Equipment for Diagnostic Radiographer. MTP Press check Graham T. D (1996) Principles of Radiological Physics. Churchill Livingstone. Ogborn et al (2000) Advancing Physics A2. Institute of Physics Roberts P. D, Smith L. N (1990) Radiographic Imaging. Churchill Livingstone Thompson C, Wakeling J (2003) AS L evel Physics. Coordinate Group Publication. On Line References Figure 1. 0 obtained from, www. catscanman. net Figure 1. 1 obtained from, www. mh. org. au Figure 1. 3 and Figure 1. 4 obtained from, www. impactscan. org/slides Figure 1. 5 obtained from, www. koehler. me. uk Figure 1. 6 and Figure 1. 7 obtained from www. impactscan. org/slides Figure 1. 8 obtained from, www. itnonline. net. Figure 1. 9 and Figure 2. 0 obtained from www. sprawls. org/resources Figure 2. 1 obtained from, www. csmc. edu Figure 2. 2 and Figure 2. 3 obtained from, www. sprawls. org/resources Figure 2. 4, Figure 2. 5 and Figure 2. 6 obtained from www. impactscan. org/slides www. radiologyinfo. org (25 February 2009) www. imaginis. com/ct-scan/ (12 March 2009) www. bbc. co. uk/dna/h2g2 (15 February 2009) www. impactscan. org/slides (12 March 2009) www. sprawls. org/resources (14 March 2009) Other References Synergy magazine publisher New Scientist Magazine Nature Magazine.