A. Computed Tomography (CT) Computed Tomography (CT) is a biomedical imaging technique which produces cross-section images also called "slices" of anatomy of the human body. Radiographic beams are made incident on the human body. The reflected radio beams create a detailed computerized picture taken with a specialized X-ray machine. CT is more precise than a standard X-ray, and provides a clearer image. Fig.1 shows a CT scan of transverse view of the brain.
As a starting point in CT diagnostic imaging the form of radiation used to provide an image are x-rays photons , this can also be called an external radiation dose which detect a pathological condition of an organ or tissue and therefore it is more organ specific. However the physics process can be described as the radiation passes through the body it is received by a detector and then integrated by a computer to obtain a cross-sectional image (axial). In this case the ability of a CT scanner is to create only axial two dimensional images using a mathematical algorithm for image reconstruction. In contrast in RNI the main property for producing a diagnostic image involves the administration of small amounts of radiotracers or usually called radiopharmaceutical drugs to the patient by injection or oral. Radio meaning the emitted of gamma rays and pharmaceutical represents the compound to which a nuclide is bounded or attached.
Both diagnostic and therapeutic radiology involve the use of ionizing radiation ( Beta, Alpha, Gamma, and x rays), with the exception of the MRI, which uses a magnetic field rather then radiation. Radiology is classified as being either diagnostic or therapeutic. Diagnostic radiology is an evaluation of the body, by means of static or dynamic images or anatomy, physiology, and alterations caused by injury or disease. A majority of these pictures are formed by passing a low or high level of x rays through the part of the body being examined, producing the static image on film. This image is called a radiograph or x ray picture.
The X-ray picture is able to be printed though the use of specialized X-ray machines. These machines work similarly to everyday cameras however, instead of using light with frequencies within the visible spectrum, the machines use electromagnetic waves with much higher frequencies which are consequently able to penetrate through thicker mediums. (howstuffworks, 2013)‘Barium Enema’ is an examination of the intestines in which a small amount of radioactive material (Barium) is inserted into the body; showing doctors even the smallest of blockages through the use of a screen. Cardiologists also use a form of X-ray (an angiogram) in order to detect blockages. This works in a very similar manner to that of the Barium Enema.
It will investigate why this machine is more suitable for utilization by the radiographers and the patients compared to other simulation modalities. Description A CT Sim is made up of three main components, CT scanner, laser system and virtual simulation application (NEEDHAM, 2009). CT scanner is an X-ray machine which produces a transverse image of the patient’s body. The scanner has a "doughnut" shaped gantry, which contains an X-ray tube. The process of X-ray production is described below: Filament is connected to low tension supply compared to cathode and anode, which are connected to high tension supply, this triggers thermoionic emission (cathode... ... middle of paper ... ...ecise contour needed to for dose calculations, treatment field planning and creating DRR’s.
“Ultrasound can be used in several different ways such as monitoring an unborn baby, diagnosing a condition or guiding a surgeon during certain procedures by using sound waves” (Ultrasound, 2011). An important change came about with the development and common use of computer technology. “Such use of a filmless radiology department was very interesting to this medical field. Digital radiography was introduced in the mid 1980’s and now competes with screen film radiography in all radiographic applications” (Bansal, 2006). Radiographs are essentially used for the diagnosis of many different diseases and injuries.
Joshua Cayetano AP Physics/Period 3 Ms. Fitzmaurice May 22nd, 2014 MRI Rough Draft Three simple letters such as “MRI”, may leave one in question of what it’s about. But MRI stands for Magnetic Resonance Imaging. In other words, an elaborated scientific form of a x-ray. It derives from Nuclear Magnetic Resonance Spectroscopy (NMR). NMR is enabling us to identify the structure of an organic molecule, but can also be applied to the imaging of the whole body organs, to what we know as an MRI.
The table is then moved, and the process is repeated, resulting in a series of thin slice images of the body over the region of interest (e.g. brain, breast, liver). These thin slice images can be assembled into a three dimensional representation of the patient's body Nowadays, PET scanning devices are most often used in conjunction with CT scanners, so that a more accurate image can be observed by the doctor for easier diagnosis of diseases or disorders. SPECT (Single Photon Emission Computed Tomography) works in a way much the same to PET. But the radioactive substances used in SPECT (Xenon-133, Technetium-99, Iodine-123) have longer decay times than those used in PET, and emit single instead of double gamma rays MRI has a more complex principle for its function; it works by creating a magnetic field so strong that the hydrogen protons in the body are forced into alignment with the magnetic field.
wiseGEEK, (2014). What Is the Difference Between an MRI and PET Scan?. [online] Available at: http://www.wisegeek.com/what-is-the-difference-between-an-mri-and-pet-scan.htm [Accessed 4 May. 2014]. Figure 1 http://hyperphysics.phy-astr.gsu.edu/hbase/nucene/nucmed.html Figure 2 http://physiology-physics.blogspot.com.au/2008/12/pet-scan-particle-physics-and.html Figure 3 http://science.howstuffworks.com/nuclear-medicine1.htm Figure 4-8 http://science.howstuffworks.com/mri3.htm Figure 9 http://medicalphysicsweb.org/cws/article/research/43526 Figure 10 http://stonybrookmedicine.edu/imaging/pet-mri Figure 11 http://www.naturalnews.com/032136_radiation_exposure_chart.html
Dr. Frourie in 1974 painfully cut organisms into thin slices, to study their internal arrangement to better understand them. Today, these people use CT scanners instead. It is a lot easier, less bloody, takes shorter time and the sample is not affected or destroyed during the procedure- the advantages are numerous. This technique enables us to visualize the inside of us humans, organisms or other objects in 3-D geometry. CTscans stands for “Computed Tomography”.