Functional magnetic resonance imaging Essays

Functional magnetic resonance imaging Essays Functional magnetic resonance imaging Essay Functional magnetic resonance imaging Essay The organic structure is opaque, hence many old ages ago cipher could see inside it without executing surgery. However today there are many non invasive techniques, such as antielectron emanation imaging ( PET ) , computed imaging ( CT ) , X-rays and magnetic resonance imagination ( MRI ) , which helps us to see inside the organic structure to assist name and handle a patient. The purpose of this essay is to compare functional magnetic resonance imagination with other non invasive techniques used to look inside the organic structure. And to find whether it is the most sufficient technique used, or if there are any alternate methods. The techniques that are traveling to be discussed in this essay are positron emanation imaging, computed imaging, magnetic resonance imagination, and functional magnetic resonance imagination. Positron emanation imaging Positron emanation imaging scanners are able expression at the physiology and anatomy of any portion of the organic structure, and are able to observe tumors, irregular and deficient blood flow to tissues, aneurisms, blood cell upsets and deficient operation of variety meats such as the thyroid and pneumonic map lacks. In order for this to happen a radioactive substance is injected into the patient. The radioactive substance is normally tagged with a radioactive atom, for illustration C-11, F-18, O-15, and N-13. These radioactive atoms are formed by pelting chemicals, by a atom gas pedal device, with neutrons to make short lived radioactive isotopes. The antielectron emanation imaging is able to observe gamma beams which are given off when the radioactive isotope emits a antielectron which collides with an negatron in the tissue. It is able to make this as it has a gamma beam sensor ; this has a series of scintillation crystals, which are each connected to a photomultiplier tubing. The crystals convert the gamma rays into photons of visible radiation ; this is so converted and amplified by the photomultiplier into electrical signals. These electrical signals are so developed into an image by a computing machine. : ( 2008 ) How positron emanation imaging ( PET ) works. Available at: hypertext transfer protocol: //www.rikenresearch.riken.jp/eng/frontline/5656 [ Accessed 25/03/10 ] Because this lone produces an image of a piece of the organic structure, hence in order for the image to be three dimensional there are legion pieces developed, which can so be assembled by the computing machine to organize a three dimensional image. The image shows blood flow or other biochemical maps depending on what radioactive substance is being used. For illustration, to bring forth an image of encephalon activity, weak radioactive glucose is injected into the patient. The radioactive glucose releases antielectrons as it is consumed by the encephalon. As the encephalon consumes the glucose, this shows which countries of the encephalon are most active. The higher the ingestion of glucose the higher the activity of the country of the encephalon. Picture screening: A normal pet scan which shows the difference in encephalon activity between declaiming a set of good memorized and practiced words ; and a set of words non practiced Available at: hypertext transfer protocol: //www.macalester.edu/psychology/whathap/UBNRP/serialkillers/pet_link.html [ Accessed 25/03/10 ] It was found that those who perform good on a hard concluding trial consume less energy so those who performed ill. ( Haier et al 1988 ) Haier believes that it shows that intelligence is related to encephalon efficiency: less efficient encephalons work harder but still carry through less ( Haier, White A ; Alkire 2003 ) There are a limited figure of PET scanners ; this is because the devices needed to make the radioactive isotopes are highly expensive, so therefore it is a hard intervention to have. Not all patients are able to undergo the intervention due to radiation degrees ; pregnant adult females are hence non suited to undergo this process. Even though the radioactive isotope is short lived it people can merely undergo this process a limited figure of times due to the radiation exposure. However there are advantages for this process, it is able to observe diseases before any alteration in the anatomy like functional magnetic resonance imaging scanners, by analyzing biochemical map. It prevents unneeded surgeries, as it is able to separate between benign and malignant tumors. Computed imaging Computed imaging green goods X raies, it is a powerful signifier of electromagnet energy. Because it has a high energy degree it will therefore base on balls straight through most of the soft stuffs in the organic structure. The image shows merely white, gray and black. White represents bone, metal and Ca. The Grey sunglassess represent variety meats, soft tissues and musculuss, and black represents air, and fat. The X-ray beam moves all around the patient, scanning from 100s of different angles, and is so set together to organize a three dimensional image of the organic structure. It is used to name malignant neoplastic disease, caput injury, and osteoporosis. The advantages of this process are that it is painless and non invasive. It is first-class for abdominal injury, and can bring forth elaborate images of the liver, kidneys and lien. There is no job for those who have implanted medical devised, unlike MRI scans. However there are besides disadvantages to this process, even though the radiation degrees are low, persons can merely undergo this procedure a limited figure of times. Pregnant adult females can non undergo this process due to the radiation, which is a hazard to the fetus. It is non really good at observing soft tissues in great item, and is non good at happening countries of the encephalon which are infected or inflamed compared to MRI scans. And there is a dye that may be used for contrast, which people may respond severely to. Image demoing an Axial CT image of a normal encephalon. Available at: hypertext transfer protocol: //www.howstuffworks.com/framed.htm? parent=cat-scan.htm A ; url=http: //www.imaginis.com/ct-scan/history.asp [ Accessed 22/03/10 ] Magnetic resonance imagination Raymond Damadian developed the first magnetic resonance imagination ( MRI ) scanner ( Gould R.T. et Al 2000 ) . It uses a really strong magnetic field and wireless moving ridges to bring forth a elaborate image of inside the organic structure. It is able to make this because most of the human organic structure is made up of H2O molecules, incorporating H atoms. These H atoms contain a proton, which aligns itself in the way of the magnetic field. Because the MRI scanner has a much higher magnetic field than the Earth, it changes the way to that of the magnet. The MRI scanner so sends radio frequence signals that are specific to hydrogen atoms, to the peculiar country that is being examined. This causes the protons to absorb energy for it to be able to whirl in a different way. When the wireless frequence signals have stopped the H protons release their surplus stored energy as they slowly return to their natural alliance. A spiral on the scanner picks this up, which is so sent to a co mputing machine. The computing machine receives mathematical informations which is converted into an image. The images provided can be used to demo if there are any abnormalcies in the tissues. MRI scans are able to observe if the patient has suffered from a shot, any hurts, and can observe tumours and diseases in any portion of the organic structure. Image demoing sagittal position of an MRI scan. FMRIB Centre ( 2005-2010 ) Available at: hypertext transfer protocol: //www.fmrib.ox.ac.uk/education/fmri/images/sagittal_scan.jpg/view [ Accessed on: 25/03/10 ] Functional magnetic resonance imagination It was discovered that O hapless hemoglobin was affected otherwise by a magnetic field than O rich hemoglobin. And so therefore it was possible to utilize these contrasts in the blood O response to map images of encephalon activity on a normal MRI. Which lead to the development of functional magnetic resonance imagination ( functional magnetic resonance imaging ) , which looks at the construction but besides the map of the encephalon. Functional MRI measures the haemodynamic response. This is the alteration in blood flow related to cognative activity, for illustration reading, emotions and listening. When nervus cells are active there is an addition in O being used, which increases the blood flow to that peculiar country. This produces activation maps, which shows what portion of the encephalon is involved in a peculiar mental procedure. For illustration the hippocampus and related median temporal lobe constructions are important for the encryption and storage of information in long- run memory. Picture demoing four functional encephalon scans obtained during a ocular memory undertaking Mark DEsposito A ; Charan Ranganath ( 2000 ) Available at: hypertext transfer protocol: //berkeley.edu/news/media/releases/2000/11/20_mri.html [ Accessed 25/03/10 ] Functional MRI has enabled us to supervise the growing and map of encephalon tumors, and can besides measure shot, injury or degenerative diseases on encephalon map. Functional MRI does non necessitate any radioactive isotopes or injections ; therefore the patient will be more comfy with holding the process done. There is a high declaration, so there is a more elaborate image obtained. It does nt utilize radiation like X raies, Computer Tomography or positron emanation imaging scans do, therefore is nt harmful to the patient or physician during the process, and many can be done if necessary. And it looks at all countries of the encephalon, as it is able to look at the image in any plane. Whereas a CT scan can merely bring forth one plane of position, the axial plane. The MRI scan can bring forth images of axial, sagittal and coronal planes, every bit good as any in between those grades, without the patient even traveling. However there are disadvantages of the equipment. It is really expensive for the equipment used ; therefore the test will be rather expensive so non many people will be able to afford to hold them. There are some people who can non undergo a functional MRI scan, because metal can non be near the scanner, for illustration those with pacesetters. And besides some people may be excessively large to be scanned. Those who are claustrophobic may happen it straitening. The patient has to maintain wholly still for the continuance of the process, which may be for a long clip, so that a clear image can be captured. If there are any little motions this may take to a deformed image, which may hold to be repeated. And it does nt look at the activities of the single nerve cells which are critical for mental map. It is hard to state precisely what encephalon activity is being represented on the scan, as the functional Magnetic resonance imaging picks up 1000s of single nerve cells at a clip, which may stand for a figure of different maps. In decision it seems that every technique is more efficient for certain countries of the organic structure, certain persons or specific diseases. Functional MRI merely looks at the map of encephalon activity, whereas CT and PET scans are able to see inside the whole organic structure. Favored scans are besides able to look at the map of the encephalon, nevertheless there are merely a limited figure of times the patient can undergo this process, and those who have implanted metal devises can non hold a MRI scan due to the magnetic field. CT scans are really good for those who need to name venters trauma, nevertheless the CT scanner does non give much item to soft tissues. PET scanners have a high sensitiveness, but lacks deciding morphology. MRI scanners have lower sensitiveness, but have a high contrast with soft tissues. So at that place have been versions, by uniting them both to acquire a more powerful instrument. This can besides be done with CT scanners and PET scanners. Mentions Columbia University ( n.d ) . The Future Role of functional MRI [ online ] . [ Accessed 07/12/09 ] . Available from: lt ; hypertext transfer protocol: //www.fmri.org/fmri.htm gt ; . Coon, Dennis A ; Mitterer, John O. ( 2008 ) Introduction to Psychology: Gatewaies to Mind and Behavior. 12th erectile dysfunction. Cengage Learning Devlin, Hannah ( 2005-2010 ) . Introduction to fMRI [ online ] . [ Accessed 08/12/09 ] . Available from: lt ; hypertext transfer protocol: //www.fmrib.ox.ac.uk/education/fmri/introduction-to-fmri/ gt ; . Erkonen, William E A ; Smith, Wilbur L ( 2009 ) Radiology 101: The rudimentss and basicss of imaging3rd erectile dysfunction. Lippincott Williams A ; Wilkins Freudenrich, Ph.D. , Craig. ( 2000 ) How Nuclear Medicine Works. [ online ] HowStuffWorks.com. [ Accessed 18/03/10 ] Available from: lt ; hypertext transfer protocol: //health.howstuffworks.com/nuclear-medicine.htm gt ; Gould, RT, Todd A. ( 2000 ) How MRI Works. [ online ] HowStuffWorks.com. [ Accessed on 8/3/10 ] Available from: lt ; hypertext transfer protocol: //healthguide.howstuffworks.com/mri.htm gt ; Harris, Tom. ( 2002 ) How CAT Scans Work. [ online ] HowStuffWorks.com. [ Accessed 22/03/10 ] Available from: lt ; hypertext transfer protocol: //health.howstuffworks.com/cat-scan.htm gt ; NHS [ online ] . ( 2009 ) MRI- scan [ online ] [ Accessed 08/12/09 ] . Available from: lt ; hypertext transfer protocol: //www.nhs.uk/Conditions/MRI-scan/Pages/Introduction.aspx. gt ; . Radiology Info ( N.D ) Professionals and cons of PET scans Available from: lt ; hypertext transfer protocol: //www.radiology-info.org/nuclear-medicine-positron-emission-tomography/pros-consside-effects.html gt ; scanDirectory.com Staff ( 2007 ) organic structure scan [ online ] [ Accessed 22/03/10 ] Available from: lt ; hypertext transfer protocol: //www.scandirectory.com/content/body_scan.asp gt ; Watson, Stephanie. ( 2008 ) How fMRI Works. [ online ] HowStuffWorks.com. [ Accessed 08/03/10 ] Available from: lt ; hypertext transfer protocol: //health.howstuffworks.com/fmri.htm gt ;