Neuroimaging includes the use of various techniques to either directly or indirectly image the structure, function, or pharmacology of the brain. It is a relatively new discipline within medicine and neuroscience. Imaging refers to the science of obtaining pictures or more complicated spatial representations, such as animations or 3-D computer graphics models, from physical things. ... Neuroanatomy is the anatomy of the nervous system. ... Pharmacology (in Greek: pharmacon (φάρμακον) meaning drug, and logos (λόγος) meaning science) is the study of how chemical substances interact with living systems. ... Comparative brain sizes In animals, the brain, or encephalon (Greek for in the head), is the control center of the central nervous system. ... Medicine is the branch of health science and the sector of public life concerned with maintaining human health or restoring it through the treatment of disease and injury. ... Neuroscience is a field of study that deals with the structure, function, development, genetics, biochemistry, physiology, pharmacology, and pathology of the nervous system, divided into the central nervous system (the brain and spinal cord), and the peripheral nervous system, consisting of the myriad nerve pathways running throughout the body. ...

It falls into two broad categories: structural imaging and functional imaging. The former deals with the overall structure of the brain and the precise diagnosis of intracranial disease and injury. The latter is used for neurological and cognitive science research and building brain-computer interfaces. It enables, for example, the processing of sensory information coming to the brain and of commands going from the brain to the organism to be "lit up" or visualized directly instead of by simple clinical inference. Rendering of human brain based on MRI data Cognitive science is usually defined as the scientific study either of mind or of intelligence (e. ... A brain-computer interface (BCI) or direct neural interface is literally a direct technological interface between a brain and a computer not requiring any motor output from the user. ... Senses are the physiological methods of perception. ... In biology and ecology, an organism (in Greek organon = instrument) is a complex adaptive system of organs that influence each other in such a way that they function as a more or less stable whole and have properties of life. ...

Neuroimaging was honored in a US Postal Service Stamp

This work is copyrighted. ... This work is copyrighted. ... A USPS Truck at Night A U.S. Post Office sign The United States Postal Service (USPS) is the United States government organization responsible for providing postal service in the United States and is generally referred to as the post office. ...

Types of brain imaging

EEG

The first EEG recording, obtained by Hans Berger in 1929.

Electroencephalography (EEG) is the first non-invasive neuroimaging technique discovered. First reported by neurologist Hans Berger in 1929, EEG measures the electrical voltage potentials from ensambles of neurons in the cerebral cortex. This technique is widely used in neuroscience research, with many stereotyped electrical potentials well-known (e.g., P300, N400). This technique is occasionally used clinically to determine brain death. First EEG tracing, by Hans Berger (1929) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Hans Berger was born in May 21, 1873, in Neuses near Coburg, Thuringia, Germany. ... Electroencephalography is the neurophysiologic measurement of the electrical activity of the brain by recording from electrodes placed on the scalp or, in special cases, on the cortex. ... Neurology is a branch of medicine dealing with the nervous system and its disorders. ... Hans Berger was born in May 21, 1873, in Neuses near Coburg, Thuringia, Germany. ... Lightning strikes during a night-time thunderstorm. ... The volt (symbol: V) is the SI derived unit of electric potential difference. ... Drawing by Santiago Ramón y Cajal of cells in the pigeon cerebellum. ... Location of the cerebral cortex Slice of the cerebral cortex, ca. ... The P300 is a neural evoked potential component of the electroencephalogram (EEG). ... The N400 is an Event-Related Potential component typically elicited by unexpected linguistic stimuli. ... Brain death is defined as a complete and irreversible cessation of brain activity. ...

EEG-recorded responses to sensory or other stimuli are called evoked potentials (EPs) or sometimes event-related potentials (ERPs). The stimuli can be auditory, visual, tactile, olfactory, gustatory, or electric. EPs can be elicited also by Transcranial magnetic stimulation.
Transcranial magnetic stimulation (TMS) is the use of powerful rapidly changing magnetic fields to induce electric fields in the brain by electromagnetic induction without the need for surgery or external electrodes. ...

MEG

Magnetoencephalography (MEG) is similar to EEG, but magnetic fields are measured instead of electric fields. Magnetoencephalography (MEG) is the measurement of the magnetic fields produced by electrical activity in the brain, usually conducted externally, using extremely sensitive devices such as SQUIDs. ... Electroencephalography is the neurophysiologic measurement of the electrical activity of the brain by recording from electrodes placed on the scalp or, in special cases, on the cortex. ...

CAT

CT scan slice showing indicating damage cause by stroke (arrow).

Computed tomography (CT or CAT) scanning uses a series of x-rays of the head taken from many different directions. Typically used for quickly viewing brain injuries, CT scanning has a computer program that uses a set of algebraic equations to estimate how much x-ray is absorbed in a small area within a cross section of the brain (Jeeves 21). In the final analysis, the harder a material is, the whiter it will appear on the scan. CT scans are primarily used for evaluating swelling from tissue damage in the brain and in assessment of ventricle size. Modern CT scanning exposes the subject to about as much radiation as a single x-ray and can provide reasonably good images in a matter of minutes.
Image File history File links CTscan. ... A stroke or cerebrovascular accident (CVA) occurs when the blood supply to a part of the brain is suddenly interrupted. ... CT apparatus in a hospital Computed tomography (CT), originally known as computed axial tomography (CAT) and body section roentgenography, is a medical imaging method employing tomography where digital geometry processing is used to generate a three-dimensional image of the internals of an object from a large series of two... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz... Algebra is the current mathematics collaboration of the week! Please help improve it to featured article standard. ...

MRI

High-resolution sagittal MRI slice at the midline.

Magnetic Resonance Imaging (MRI) uses magnetic fields and radio waves to produce high quality two- or three-dimensional images of brain structures without injecting radioactive tracers. During an MRI, a large cylindrical magnet creates a magnetic field around the head of the patient through which radio waves are sent. When the magnetic field is imposed, each point in space has a unique radio frequency at which the signal is received and transmitted (Preuss). Sensors read the frequencies and a computer uses the information to construct an image. The detection mechanisms are so precise that changes in structures over time can be detected. Using MRI, scientists can create images of both surface and subsurface structures with a high degree of anatomical detail. MRI scans can produce cross sectional images in any direction from top to bottom, side to side, or front to back. The problem with original MRI technology was that while it provides a detailed assessment of the physical appearance of the brain, it fails to provide information about how well the brain is working at the time of imaging. The distinction is now made between MRI imaging and functional imaging since the brain's function rather than the brain's structure is of interest.
Image File history File links MRIscan. ... Magnetic Resonance Image showing a vertical (sagittal) cross section through a human head. ... Magnetic field lines of a bar magnet shown by iron filings on paper A magnet is an object that has a magnetic field. ... It has been suggested that Magnetic field density be merged into this article or section. ... Rough plot of Earths atmospheric transmittance (or opacity) to various wavelengths of electromagnetic radiation, including radio waves. ... Anatomical drawing of the human muscles from the Encyclopédie. ...

fMRI

Axial MRI slice at the level of the basal ganglia, showing fMRI BOLD signal changes overlayed in red (increase) and blue (decrease) tones.

Functional magnetic resonance imaging (fMRI) relies on the paramagnetic properties of oxygenated and deoxygenated hemoglobin to see images of changing blood flow in the brain associated with neural activity. This allows images to be generated that reflect which structures are activated (and how) during performance of different tasks. Most fMRI scanners allows subjects to be presented with different visual images, sounds and touch stimuli, and to make different actions such as pressing a button or moving a joystick. Consequently fMRI can be used to reveal brain structures and processes associated with perception, thought and action. The resolution of fMRI is about two or three millimeters at present, limited by the spatial spread of the hemodynamic response to neural activity. It has largely superseded PET for the study of brain activation patterns. PET, however, retains the significant advantage of being able to identify specific brain receptors associated with particular neurotransmitters through its ability to image radiolabelled receptor ligands.
Image File history File links FMRIscan. ... The basal ganglia are a group of nuclei in the brain associated with motor and learning functions. ... Functional magnetic resonance imaging (fMRI) is the use of MRI to measure the haemodynamic response related to neural activity in the brain or spinal cord of humans or other animals. ... 3-dimensional structure of hemoglobin. ... Neurotransmitters are chemicals that are used to relay, amplify and modulate electrical signals between a presynaptic and a postsynaptic neuron. ...

PET

PET scan of normal 20 year old brain.

Positron Emission Tomography (PET) measures emissions from radioactively labeled metabolically active chemicals that have been injected into the bloodstream and uses the data to produce two or three-dimensional images of the distribution of the chemicals throughout the brain (Nilsson 57). The positron emitting radioisotopes used are produced by a cyclotron and chemicals are labelled with these radioactive atoms. The labeled compound, called a radiotracer, is injected into the bloodstream and eventually makes its way to the brain. Sensors in the PET scanner detect the radioactivity as the compound accumulates in different regions of the brain. A computer uses the data gathered by the sensors to create multicolored two or three-dimensional images that show where the compound acts in the brain. Image File history File links PETscan. ... Image of a typical positron emission tomography (PET) facility Positron emission tomography (PET) is a nuclear medicine medical imaging technique which produces a three dimensional image or map of functional processes in the body. ... The first detection of the positron in 1932 by Carl D. Anderson The positron is the antiparticle or the antimatter counterpart of the electron. ... A radionuclide is an atom with an unstable nucleus. ... A pair of Dee electrodes with loops of coolant pipes on their surface at the Lawrence Hall of Science. ...

The greatest benefit of PET scanning is that different compounds can show blood flow and oxygen and glucose metabolism in the tissues of the working brain. These measurements reflect the amount of brain activity in the various regions of the brain and allow us to learn more about how the brain works. PET scans were superior in terms of resolution and speed of completion (as little as 30 seconds) when they first came online. The improved resolution permitted better judgments to be made as to the area of the brain activated by a particular task. The biggest drawback of PET scanning is that because the radioactivity decays rapidly, it is limited to monitoring short tasks (Nilsson 60). Before fMRI technology came online, PET scanning was the preferred method of brain imaging, and it still continues to make large contributions to neuroscience.
Glucose (Glc), a monosaccharide, is one of the most important carbohydrates. ... Santorio Santorio (1561-1636) in his steelyard balance, from Ars de statica medecina, first published 1614 Metabolism (from μεταβολισμος (metabolismos)) is the biochemical modification of chemical compounds in living organisms anggjgjhnd cell (b). ... Neuroscience is a field of study that deals with the structure, function, development, genetics, biochemistry, physiology, pharmacology, and pathology of the nervous system, divided into the central nervous system (the brain and spinal cord), and the peripheral nervous system, consisting of the myriad nerve pathways running throughout the body. ...

SPECT

SPECT is similar to PET. Single photon emission computed tomography (SPECT) uses gamma ray emitting radioisotopes and a gamma camera to record data that a computer uses to construct two- or three-dimensional images of active brain regions (Ball). SPECT relies on an injection of radioactive tracer, which is rapidly taken up by the brain but does not redistribute. Uptake of SPECT agent is nearly 100% complete within 30 – 60s, reflecting cerebral blood flow (CBF) at the time of injection. These properties of SPECT make it particularly well suited for epilepsy imaging, which is usually made difficult by problems with patient movement and variable seizure types. SPECT provides a "snapshot" of cerebral blood flow since scans can be aquired after seizure termination (so long as the radioactive tracer was injected at the time of the seizure). A significant limitation of SPECT is its poor resolution (about 1 cm) compared to that of MRI.
SPECT (Single Photon Emission Computed Tomography) is a nuclear medicine tomographic imaging technique using gamma rays. ... This article is about electromagnetic radiation. ... A radionuclide is an atom with an unstable nucleus. ... A gamma camera is an imaging device, most commonly used as a medical imaging device nuclear medicine. ...

History

See main article History of neuroimaging The history of neuroimaging, began in the early 1900s with a technique called pneumoencephalography. ...

In 1918 the American neurosurgeon Walter Dandy introduced the technique of ventriculography. X-ray images of the ventricular system within the brain were obtained by injection of filtered air directly into one or both lateral ventricles of the brain. Dandy also observed that air introduced into the subarachnoid space via lumbar spinal puncture could enter the cerebral ventricles and also demonstrate the cerebrospinal fluid compartments around the base of the brain and over its surface. This technique was called pneumoencephalography. In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz... The ventricular system is a set of structures in the brain continuous with the central canal of the spinal cord. ... Pneumoencephalography (sometimes abbreviated PEG) is a medical procedure in which cerebrospinal fluid is drained from around the brain and replaced with air, oxygen, or helium to allow the structure of the brain to show up more clearly on an X-ray picture. ...

In 1927 Egas Moniz, professor of neurology in Lisbon, introduced cerebral angiography, whereby both normal and abnormal blood vessels in and around the brain could be visualized with great accuracy. António Caetano de Abreu Freire Egas Moniz (November 29, 1874 - December 13, 1955) was a Portuguese physician and neurologist. ... District or region Lisbon Mayor   - Party Carmona Rodrigues PSD Area 84. ... Angiography or arteriography is a medical imaging technique in which an X-ray picture is taken to visualize the inner opening of blood filled structures, including arteries, veins and the heart chambers. ...

In the early 1970s, Allan McLeod Cormack and Godfrey Newbold Hounsfield brought about the use computerized axial tomography (CAT or CT scanning), and ever more detailed anatomic images of the brain became available for diagnostic and research purposes. Cormack and Hounsfield won the 1979 Nobel Prize for Physiology or Medicine for their work. Soon after the introduction of CAT, the development of radioligands allowed single photon emission computed tomography (SPECT) and positron emission tomography (PET). Allan M. Cormack at Tufts University Allan MacLeod Cormack (February 23, 1924 – May 7, 1998) was a South African-born American physicist who shared a part of the 1979 Nobel Prize in Physiology or Medicine for his work on the computerized axial tomography (CAT) scan. ... Sir Godfrey Newbold Hounsfield (28 August 1919 - 12 August 2004) was an English electrical engineer who shared the 1979 Nobel Prize for Physiology or Medicine with Allan McLeod Cormack for his part in developing the diagnostic technique of computerized axial tomography (CAT). ... CAT apparatus in a hospital Computed axial tomography (CAT), computer-assisted tomography, computed tomography, CT, or body section roentgenography is the process of using digital processing to generate a three-dimensional image of the internals of an object from a large series of two-dimensional X-ray images taken around... List of Nobel Prize laureates in Physiology or Medicine from 1901 to the present day. ... A radioligand is a radioactive biochemical substance that is used to study the receptor systems of the brain. ... SPECT (Single Photon Emission Computed Tomography) is a nuclear medicine tomographic imaging technique using gamma rays. ... Image of a typical positron emission tomography (PET) facility Positron emission tomography (PET) is a nuclear medicine medical imaging technique which produces a three dimensional image or map of functional processes in the body. ...

More or less concurrently, magnetic resonance imaging (MRI or MR scanning) was developed by researchers including Peter Mansfield and Paul Lauterbur, who were awarded the Nobel Prize for Physiology or Medicine in 2003. During the 1980s a veritable explosion of technical refinements and diagnostic MR applications took place. Scientists soon learned that the large blood flow changes measured by PET were also imaged by MRI. Functional magnetic resonance imaging (fMRI) was born. Since the 1990s, fMRI has come to dominate the brain mapping field due to its low invasiveness, lack of radiation exposure, and relatively wide availability. Magnetic Resonance Image showing a vertical (sagittal) cross section through a human head. ... Sir Peter Mansfield FRS, (born October 9, 1933), is a British physicist who was awarded the 2003 Nobel Prize in Physiology or Medicine for his discoveries concerning magnetic resonance imaging (MRI). ... Paul Christian Lauterbur, (born May 6, 1929) is an American chemist who shared the Nobel Prize in Physiology or Medicine in 2003 with Peter Mansfield for his work which made the development of magnetic resonance imaging (MRI) possible. ... List of Nobel Prize laureates in Physiology or Medicine from 1901 to the present day. ... Functional magnetic resonance imaging (fMRI) is the use of MRI to measure the haemodynamic response related to neural activity in the brain or spinal cord of humans or other animals. ...

In early 2000s the field of neuroimaging reached the stage where limited practical applications of functional brain imaging became feasible. The main application area is crude forms of brain-computer interface. A direct mind-computer interface or direct neural interface is literally that - a direct cybernetic link between a mind and a computer. ...

See also

• Functional neuroimaging
• History of brain imaging
• Human Cognome Project
• Medical imaging
• Statistical parametric mapping

Functional neuroimaging is the use of brain imaging technology to measure an aspect of brain function, often with a view to understanding the relationship between activity in certain brain areas and specific mental functions. ... The history of brain imaging, began in the early 1900s with a technique called pneumoencephalography. ... The Human Cognome Project seeks to reverse-engineer the human brain, parallelling in many ways the Human Genome Project and its success in deciphering the human genome. ... Medical imaging is the process by which physicians evaluate an area of the subjects body that is not normally visible. ... Statistical parametric mapping or SPM is a statistical technique for examining differences in brain activity recorded during functional neuroimaging experiments using neuroimaging technologies such as fMRI or PET. It may also refer to a specific piece of software created by the Wellcome Department of Imaging Neuroscience (part of University College...

Works cited

• Ball, Philip. "Brain Imaging Explained." Online at http://www.nature.com/nsu/010712/010712-13.html
• Beaumont, J. Graham. Introduction to Neuropsychology. New York: The Guilford Press, 1983. 314 pages.
• Changeux, Jean-Pierre. Neuronal Man: The Biology of Mind. New York: Oxford University Press, 1985. 348 pages.
  • Jeeves, Malcom. Mind Fields: Reflections on the Science of Mind and Brain. Grand Rapids, MI: Baker Books, 1994. 141 pages.
• Johnson, Keith A. "Neuroimaging Primer." [1]
• Leventon, Michael. "Transcranial Magnetic Stimulation." In assosiation with MIT AI Lab. [2]
• Lister, Richard G. and Herbert J. Weingartner. Perspectives on Cognitive Neuroscience. New York: Oxford University Press, 1991. 508 pages.
• Mattson, James and Merrill Simon. The Pioneers of NMR and Magnetic Resonance in Medicine. United States: Dean Books Company, 1996. 838 pages.
• Nilsson, Lars-Goran and Hans J. Markowitsch. Cognitive Neuroscience of Memory. Seattle: Hogrefe & Huber Publishers, 1999. 307 pages.
• Norman, Donald A. Perspectives on Cognitive Science. New Jersey: Ablex Publishing Corporation, 1981. 303 pages.
• Pande, G.C. "Neurosciences and Philosophy." [3]
• Rapp, Brenda. The Handbook of Cognitive Neuropsychology. Ann Arbor, MI: Psychology Press, 2001. 652 pages.
• Shorey, Jamie. "Foundations of fMRI." [4]