Computed Tomography - Research Paper Example

COMPUTED TOMOGRAPHY (CT) SCAN d COMPUTED TOMOGRAPHY (CT) SCAN Computed tomography is a non-invasive diagnostic imaging technology that reveals the internal structure of a body with having to cut it open. A two dimensional imaging is generated when a body is scanned by a three dimensional machine called a CT scanner (Kalender, 2005). A revolutionary technology, computed tomography has gained popularity within a wide range of possible medical aspects like dentistry to cardiovascular monitoring. Digital geometry processing is used to provide a detailed multi-dimensional image that provides diagnostic insights with just one rotation of the axis. The last two decades have seen popularity in terms of the increase of usage and new technological implications that can enhance this machine to produce even more detailed imaging solutions in the future. That being said, the potential side effects of this imaging that have been known to cause cancer or kidney problems in most cases, make a strong case against the development and use of such a technology. This paper will elaborate on the technology and its usage with a study on the potential side effects of this kind of imaging. It will also shed light on is wide spread application in today’s medical world and means through which the harmful implications from the use of radiation technology of CT scanning can be minimized. INTRODUCTION The word tomography is derived from the Greek language where ‘tomo’ means ‘slice’ and ‘graphien’ means ‘write’ (Medical News Today, 2013). The technology basically involves the creation of 3-D imaging with the help of many 2-D images taken of the body, referring to the ‘slicing’ of images. First introduced in the 1970s, the technology has come a long way as far as the mechanism and clinical usage patterns of this technology are concerned. “The controllable harm that CT scanning technology pose do not provide just grounds to deem the whole technology negative” Starting off with the technology itself, computing tomography or Ct scanning conventionally makes use of an x-ray tube and sensory detectors that rotate behind the circular surface of the scanning head. Several functional options enable doctors to focus on a specialized scan that may be used to evaluate a specific body part for example blood vessels, nerves or bones. As the rotation takes place several mages are captured and collected as sonograms. These multiple sonograms are then made into information that can be interpreted. Sonograms combine through tomographic reconstruction to produce a series of cross sectional images. There are various types of mathematical and geometric techniques that can be used for this conversion, like linear algebra, filtered back projection etc. pixels refer to micro-images that can be adjusted by altering the field of view. However, these pixels combine ultimately to form a CT scan image. This kind of imaging gives a more detailed and specific imaging option as compared to conventional x-rays and thus the use of CT scans for various diagnosis have increased greatly in today’s world. Now since the technology makes use of several x-ray imaging to form one comprehensive one, researchers argue that submitting a body to over radiation form x-rays in a CT scan can make its prone to cancer or kidney problems. This is because the strong rays of the machine hit the DNA directly and create alterations that may also entice them to turn into tumors. The extent of exposure to radiation as a result of CT scan can be assumed through the fact that it exposes a person to 150 to 1100 times more radiation than a normal x-ray does. Another alarming fact is that a single CT scan is said to expose a person to the amount of radiation he would normally be exposed to during the year through the nature or environment. CT scans allows swift detection of diseases or illnesses that are not possible to diagnose through normal x-rays or other non-evasive means. According to the researchers at the National Cancer Institute, about 29000 cancer cases in the future will be due to the 72 million CT scans performed in the year 2007 (Cancer.gov, 2014). This is equal to 2% of the total number of cancers diagnosed in a year. This brings us to the other school of thought that states that the benefits of CT scan outweigh the harm that it causes. Where a tiny percent of the patients are exposed to cancerous implications the majority benefits from the early diagnosis or exact pin-pointing of a disease or tumor that may save their lives. In order to ascertain the authenticity of the two claims, it is important to study the advantages and disadvantages of CT scanning. On the positive side, this is a form of non-evasive review that helps specific diagnosis, making it less time consuming or confusing. It is more comprehensive as compared to ultrasonography or MRI scanning as it allows most of the systems to be scanned may it be the head or the legs. It allows cost savings as it reduces the need of explanatory surgeries; extra hospitalization period and most importantly it guide the medical treatment procedure. This is because it helps determining the time and urgency of surgeries if required. They also allow more appropriate placement of patient as it reveal the intensity and seriousness of the situation more clearly. It is a quick procedure and allows a large portion to be scanned for a specific information characteristic. On the down side, the top of the list is the potential exposure to cancer. As explained earlier, the strong radiation affects the DNA and alters it to an extent that they can turn into tumors, making the person vulnerable to cancer. The same is the case that goes with kidney problems as toxity of kidneys can lead to complications and even kidney failure. On the other hand, the Ct scanning procedure is highly expensive for hospitals and clinics. But since it allows clearer detection of possible diseases, they are even recommended because the doctors are too lazy to run less harmful yet more and cumbersome tests. This laziness can also lead to mismanagement and higher institutional cost. Another hurdle is that of too much information. When the CT scan shows almost every possible complication or diagnosis, there are more chances for doctors to feel confused and wrongly diagnose a disease that may not be as fatal as the one whose symptoms on the CT scan are minor. There is no arguing that the technology has revolutionized medical imaging the diagnosis in today’s world. The harmful effects go hand in hand with the benefits that each technology offers. However, the debate remains whether exposing a minute percentage of the people to cancer is worth saving the lives of many others. The statistics paint a horrific picture about the possible outcomes of the Ct scans currently being run all over the world and how they can potentially be translated to cancer in the coming years. INSTRUMENTATION The major components of a CT scanner are: X-ray Tube and high voltage generator: Consisting of anodes and cathodes the x-ray tube generates the first imaging. When the cathodes emit high speed electrons to the anode, it leads to an explosion of electrons as a result of the collision, making x-ray photons. Thus, the intensity of x-ray photons is dependent upon the number of electrons held by the anode. The intensity of the x-ray depends on the difference in the powers between the anodes and cathodes, determining the impact of their collision. The anode and cathode are present in a glass tube with high internal pressure and the seals of this tube are flexible in terms of handling variable thermal expansion or contraction. To maintain the pressure as a result of the collision, voltage and current are given to the tube and the extra energy dissipates as heat during the process. X-ray detection and data acquisition: Detectors such as Xenon offer low quantum detection efficiency, allowing the photons to travel through the detector easily, for image reconstruction. These detectors consist of tungsten which carry charge and high and low voltage plates. When the photon strikes the cell, the xenon gas is ionized in an interaction that has more ionizing effect. Ionized xenon is attracted by the low voltage plates and the free ones travel to the high voltage plates. A different kind of detector plates is solid state ones that react photo-electrically with the scintillator, which is coated with reflective matte. This allows it to produce photodiodes upon the reaction of electrons and resulting radiation. The quantum detection efficiency of solid state detectors is better than a Xenon detector. Gantry: This facilitates the rotation of the x-ray tube and is strong enough to bear the forces of pressure that it is subjected to. Collimators and Filters: Collimators restrict the radiation or x-rays from reaching the patient. A filter allows low energy x-rays to be absorbed without affecting the detection (Iberg, 2014). Reconstruction engine: This is where the x-ray is given a proper form in terms of processing in image reconstruction. USAGE The usage of CT scanning was initially minimal as it was recommended to only those people whose problems could not be diagnosed through the conventional tests. From being the last resort to its current position as the first recommendation at the slightest doubt of cancer/tumor has led to the vast magnitude of problems that have surfaced. Focusing on the current usage of Ct scans it is commonly used for the following: Assessment of the structure or shape of a body part- internal or external Measurement of bone strength( bone marrow density) As an aid or guide that can help the doctors determine the flow of procedure and surgeries. Used to diagnose diseases mostly vascular or cancer To diagnose injuries and potential complications To provide visual aid for radiotherapy To provide a guide for an invasive procedure like biopsy. These are just some of the popular uses of CT scans (Better Health Channel, 2014). With the advancement of time it is being entrenched into other areas of medicine like dentistry, physiotherapy etc. the increased usage for even the minutest of problems pose a problem as the patients are then subjected to over dose of radiation that can be avoided. The problem lies not with the technology rather with the people who use it, when it is used and the disregard for the minute percentage of population that can be the victims of the harmful effects of the this kind of radiation imaging. The solution to this problem is proposing alternate technologies and going back to the initial use of CT scanning, only as a last resort for diagnosis and not as a first step. Secondly it is important that investment is done in research in order to reduce the harmful effects of radiation. Alternate technologies can be developed for diagnostic purposes that can be useful on a mass scale and not just the greater part of the population having run CT scans. Reducing the dosage of radiation can help greatly in reducing the health risks. Many clinicians and medical associations are looking into ways to reduce the amount of radiation. For example two radiologist from Massachusetts General Hospital claim that the radiation levels can be dropped drastically by up to 75% by reducing the quality of the image (Storrs, 2014). This has led to the clinics levying restrictions on the superfluous imaging for the minor diagnostic procedures. CONCLUSION Technology is negative only when it is misused. When the doctors are made aware of the consequences of too many CT scan recommendations they are bound to refrain from advising it unless it is necessary. The use of CT scanners may have quadrupled since 1996 but the harmful effects are also surfacing with the time. In order to reduce the extent of radiation, the quality imaging feature should be use only under dire circumstances. Improving softwares and technology to come up with new diagnostic machines that use lower radiation levels can also help in tackling this problem. The change is gradual but it is emerging. It is not right to deem a whole technology harmful because of its side effects when it is beneficial on a larger scale. However empowering the patients to have a say in the level of radiation they are willing to be exposed to, making doctors less prone to advising unnecessary or duplicative tests and taking steps to control levels of radiations are some of the main ways through which this problem can be tackled. That being said, many hospitals and doctors have started taking steps to ensure that they only recommend radiation under serious circumstances and are willing to sacrifice image quality for the long term negative implications of CT scans (Linebaugh, 2014). Even though the change is emerging it is gradual in application as the softwares are expensive to install and take time in getting used to. These less harmful softwares are also time consuming and thus cannot be used under emergency situations. Continuous research and attention to the implications of CT scanning can help us reap the positive benefits of the technology and minimizing the level of harm that it proposes. REFERENCES: Better Health Channel. (2014). CT scan - Better Health Channel. [online] Retrieved from: http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/CT_scan [Accessed: 11 Apr 2014]. Cancer.gov. (2014). NCI Cancer Bulletin for January 26, 2010 - National Cancer Institute. [online] Retrieved from: http://www.cancer.gov/aboutnci/ncicancerbulletin/archive/2010/012610/page8 [Accessed: 11 Apr 2014]. Kalender, W. (2005). Computed tomography. Erlangen: Publicis Corporate Pub. Linebaugh, K. (2014). New Efforts Look to Cut Radiation From CT Scans. [online] Retrieved from: http://online.wsj.com/news/articles/SB10001424127887324662404578332592947022334 [Accessed: 11 Apr 2014]. Medical News Today. (2013). What Is a CT Scan? What Is a CAT Scan?. [online] Retrieved from: http://www.medicalnewstoday.com/articles/153201.php [Accessed: 11 Apr 2014]. Storrs, C. (2014). How Much Do CT Scans Increase the Risk of Cancer?. [online] Retrieved from: http://www.scientificamerican.com/article/how-much-ct-scans-increase-risk-cancer/ [Accessed: 11 Apr 2014]. Iberg, B. (2014). Major Components of CT Scanner - BIOE 414 Instrumentation Projects - University of Illinois - Engineering Wiki. [online] Wiki.engr.illinois.edu. Available at: https://wiki.engr.illinois.edu/display/BIOE414/Major+Components+of+CT+Scanner [Accessed 3 May. 2014]. Read More