Part 1
Condition- Brain Tumor
Medical technologies chosen- PET and MRI
A PET (Positron Emitting Tomography) scan creates 3-D images of the body. It does this by using radioactive tracers, which are usually administered to a patient through injection. The tracers are made up of carrier molecules that are tightly bonded to a radioactive atom, called an isotope. The carrier molecule can interact with and bind to specific protein or sugars in the body the carrier molecule that will be used depends on what the doctor is looking for. If the doctor suspect a brain tumour they may use radiotracers which has lower background activity in normal brain tissue compared to FDG (Fluoro Deoxy Glucose), a modified form of glucose. The isotope produces small particles called positrons, which interact with surrounding electrons. This interaction results in the annihilation of both particles, releasing two photons that speed off in opposite directions (Fig 2). The gamma ray detectors in the PET scanner measure these photons and use this information to create an image of the area under examination. (Fig 1, 3)
MRI or Magnetic resonance imaging uses several magnetic fields, each to physically align hydrogen atoms which are abundant in the human body since we are made of about 70% water. Without MRI these atoms’ natural state is constantly randomly spinning (Fig 4) but with MRI all the atoms line up in the direction of the field. The machine then applies a radio frequency (RF) pulse that is specific to the hydrogen atom, which causes all the atoms to align either north or south (Fig 5, 6). The system directs this pulse to the area being examined, in this case, the brain, which causes the atoms to spin again in a different direction...
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... Gould, R. and Edmonds, M. (2014). HowStuffWorks "What Else is Going On in an MRI Scan?". [online] HowStuffWorks. Available at: http://science.howstuffworks.com/mri4.htm [Accessed 4 May. 2014].
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
My interest in MRI started when I first read the book “MRI, The Basics” written by the author Ray Hashemi. By the time I successfully finished my MRI clinical placement in Tehran University of Medical Sciences, I knew for sure that MRI would be the field I would be choosing to take on. What attracts me most about MRI is how beautifully scientist could create a technology that can take advantage of the magnetic moments of human body for imaging it without any harms of ionizing radiation. Although there are drawbacks to MRI, combining it with other modalities would be a more effective approach to an accurate diagnosis.
Other testing procedures that are commonly employed, in order to gain a better visual image of the excitatory activity in the brain are the PET scan and the MRI. According to Kalat (2004), these methods are non-invasive, meaning that they don’t require the insertion of objects into the brain, yet they yield results that allow researchers to record brain activity. The PET scan (positron emission tomography) involves the researcher injecting a radioactive chemical into the patient’s body, which is then absorbed mainly by the brain’s most active cells. With the use of radioactive detectors, placed around the patient’s head, a map is produced that shows which areas of the brain are most active.
"Zoologist Salary - How Much Does Zoologists Make?" The Richest We Follow Money The Extraordinary Zoologist Salary How Much Does Zoologists Make Comments. Web. 28 Mar. 2014.
Many different "snapshots" (at many angles through the patient) are collected during one complete rotation. For each rotation of the X-ray source and detector assembly, the image data are sent to a computer to reconstruct all of the individual "snapshots" into one or multiple cross-sectional images (slices) of the internal organs and tissues [19]. Fig.2 shows the CT images for multiple slices of the brain. The minimum and maximum number of CT slices range from 1 to 64 and 320 [18, 19].
One of the main reasons that MRI works is because of the patient themselves. Water is 80% of what our bodies are made up of. An MRI machine uses the water molecules in the body to create an image. The MRI uses water molecules to move in different direction which creates some type of electrical current. By moving the water molecules the technologist can distinguish which way they want the image to lay. An MRI machine mainly is used for soft tissue, organs, ligaments, and spinal cords. The MRI machine is a giant magnet. The magnet is made up of different forces and strengths. There is another giant magnet that creates some type of electrical current around the patient lying in ...
This assignment will endeavour to demonstrate the map of medicine as followed within the National Health Service for the diagnosis, treatment and follow-up of abdominal aortic aneurysms (AAA). It shall discuss the current AAA screening programme being implemented across the United Kingdom to include the use of Ultrasound and Computed Tomography (CT) as imaging modalities in the demonstration of AAAs. Both the advantages and disadvantages of the modalities used during the diagnosis and treatment of AAA will be shown.
As previously stated, neuroimaging science and study began in the early 1900s. The “great granddaddy” of functional brain viewing is electroencephalography, or EEG, and was invented by a German researcher by the name of Hans Berger. This exceptional neurologist discovered that the electrical activity of the brain is detectable outside the head. Following Berger’s steps, a group of scientists came up with ...
Magnetic resonance angiography (MRA), similar to CT, uses a magnetic field and pulses of radio wave energy to provide pictures of blood vessels inside the body. A dye is often used during the procedure to make blood vessels appear clearer. Lastly, a cerebral angiogram may be done. This is an x-ray test, where a catheter is inserted into a blood vessel, usually in the groin or arm, and moved from the vessel into the brain. A dye is also injected.
Since the brain is extremely fragile and difficult to access without risking further damage, imaging techniques are used frequently as a noninvasive method of visualizing the brain’s structure and activity. Today's technology provides many useful tools for studying the brain. But even with our highest technology out there we do not know everything definitely. We do have fallbacks at times and these fallbacks can lead to serious problems.
Now with the dangerous jobs in the world and even the dangerous playgrounds, electronic imaging is needed. Electronic imaging, an outstanding technological advancement, helps views bones, organs, and cancerous cells within the body. X-ray or radiograph was the first type of electronic imaging introduced into the medical field. This played an important part in the medical field because it allowed doctors to see broken bones and inflammation inside of organs. Another important electronic imaging that was introduce was the MRI. Magnetic resonance imaging (MRI) aids physicians in seeing soft tissues in the body. With the help of MRIs doctors are able to see whether those tissues are normal or damaged. A little later on functional MRIs were created to see the soft tissues function. Functional MRIs are commonly u...
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CTscans stands for “Computed Tomography”. It is a way of looking inside your body using a special camera. It is an advanced scanning x-ray and computer system that makes detailed pictures of horizontal cross-sections of the body, or the part of the body that is x-rayed. A CT scan is a diagnostic test that combines the use of x-ray with computer technology. A series of x-beams from many different angles are used to get these cross-sectional images of the patient’s body. In a computer, these pictures are assembled into a 3-dimentianal picture that can display organs, tissues, bones, and any such thing. It can even show ducts, blood vessels and tumors. One of the advantages of CT is that it clearly shows soft tissue structures (such as brain), as well as dense tissue structure (such as bone). The pictures of a Ctscanner are a lot more detailed than the pictures of a regular X-ray machine. It can make pictures of areas protected or surrounded by bones, which a regular X-ray machine can not. Because of this, a CT scanner is said to be 100 times as affective and clever as an ordinary X-ray, and can therefore diagnose some diseases a lot earlier and quicker. It is recent technology that has made it possible to accurately scan objects into a computer in three dimensions, even though the machines and ideas were developed in the 1970s. In the 70s doctors started to use this new type of machine that could give detailed pictures of organs that the older type of x-ray, machine could not give.
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