PET scan


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PET scan

(pĕt) or

positron emission tomography

(pŏz`ĭtrŏn' ĭmĭsh`ən təmŏg`rəfē), a medical imaging technique that monitors metabolic, or biochemical, activity in the brain and other organs by tracking the movement and concentration of a radioactive tracer injected into the bloodstream. The technique uses special computerized imaging equipment and rings of detectors surrounding the patient to record gamma radiationgamma radiation,
high-energy photons emitted as one of the three types of radiation resulting from natural radioactivity. It is the most energetic form of electromagnetic radiation, with a very short wavelength (high frequency).
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 produced when positrons (positively charged particles) emitted by the tracer collide with electrons.

PET scans are especially valuable in imaging the brain. They are used in medicine to diagnose brain tumors and strokes, and to locate the origins of epileptic activity; in psychiatry to examine brain function in schizophreniaschizophrenia
, group of severe mental disorders characterized by reality distortions resulting in unusual thought patterns and behaviors. Because there is often little or no logical relationship between the thoughts and feelings of a person with schizophrenia, the disorder has
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, bipolar disorderbipolar disorder,
formerly manic-depressive disorder
or manic-depression,
severe mental disorder involving manic episodes that are usually accompanied by episodes of depression.
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, and other mental illnesses; and in neuropsychology to study such brain functions and capabilities as speech, reading, memory, and dreaming.

References in periodicals archive ?
"Requests for PET scans for Powys residents from hospitals in England are made through the Individual Patient Funding Request process and our aim is to ensure that these requests are considered promptly.
The National Hospital Insurance Fund is covering the full cost of the PET scan, estimated at Sh69,500 per patient.
Studies have demonstrated that a lower plasma A?42/A?40 ratio correlates with brain amyloidosis determined by amyloid PET scans.
Cherry said he expects EXPLORER will have a profound impact on clinical research and patient care because it produces higher-quality diagnostic PET scans than have ever been possible.
PLAN TREATMENTA PET scan is used to diagnose certain health conditions, to plan treatment, find out how an existing condition is developing, and check how effective treatment is.For some patients, going for a PET scan is seen as a favourable route to establishing the extent of the cancer than other tests, or having to undergo an exploratory operation.
Sulantha Mathotaarachchi, a computer scientist in the research team, used hundreds of amyloid PET scans of patients with mild cognitive impairment from the ADNI database to train the algorithm to recognize which individuals would develop Alzheimer's before symptoms began.
Initial tests in healthy people showed that PET scans can detect the default mode network, just as fMRI scans do.
Despite the information that can be gleaned from a PET scan, it is not a test that should be administered to everyone.
Managing Director of Siemens which has provided this equipment in his speech said that PET scan is very useful in diagnosis of various neurology, cardiology and oncology disorders.
Gandy and Sano are hopeful that the new amyloid PET scan will help reduce misdiagnoses.
Then I wouldn't have to travel 50 miles to a broken-down hospital in Newcastle to get a PET scan.