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 ?
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.
Because it uses a radioactive tracer, patients and physicians should be mindful that a PET scan contributes to an individual's accumulated radioactivity exposure.
Many problems remain with CT and MRI; hence for detection of disease at a very early stage, PET scan has been installed at NMI for better diagnosis.
Medicare does not yet cover the amyloid PET scan, but some private insurance may pay part of the costs.
The solution is to combine the findings of a PET scan with those of a conventional imaging study (usually a CT scan) that can provide detailed anatomical information.
We now have a PET scan that uses ligands that were originally used to label the [amyloid] plaques at autopsy," Dr.
PET scans are very expensive and few centres have them so you may have to travel to get your scan.
Workman's failure to disclose the results of the PET scan to her at the time he received the results of the scan together with the radiologist's notations and the last time he saw the patient, which was on December 14, 2006, at the earliest or March 2007 at the latest.
Doctors seem to have a Alzheimer's-centric approach to PET scans," said Dr.
He said a PET scan could measure vital functions such as blood flow, oxygen use, and glucose metabolism, which helps doctors identify abnormal from normal functioning organs and tissues.