How is possible to scan the human bodt by using PET?

Answer 1

here this is a little easier to comprehend:
(theres no simple answer, its nuclear technology, it involves radiation via radioactive isotopes)

heres another site thats for students, theres a flash tutorial:
http://www.howpetworks.com/

Positron emission tomography (PET) is a nuclear medical imaging technique. It can be used to diagnose a wide variety of diseases, including cancer and heart disease. Like other nuclear medicine techniques, it involves injecting a radioactive isotope into a patient. This isotope decays by positron (beta positive) emission.

As the isotope decays in the body, the emitted positrons annihilate with electrons. Each annihilation produces gamma rays, which are emitted in opposite directions. These can be detected in a PET scanner. The detected annihilations are used to produce a three-dimensional image of functional processes in the body.
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To conduct the scan, a short-lived radioactive tracer isotope which decays by emitting a positron, and which has been chemically incorporated into a metabolically active molecule, is injected into the living subject (usually into blood circulation). There is a waiting period while the metabolically active molecule (most commonly fluorodeoxyglucose (FDG), a sugar, for which the waiting period is typically an hour) becomes concentrated in tissues of interest; then the subject is placed in the imaging scanner.

How the scanner operates
As the radioisotope undergoes positive beta decay, it emits a positron (the antimatter counterpart of an electron). After travelling up to a few millimeters the positron encounters and annihilates with an electron, producing a pair of annihilation photons moving in nearly opposite directions. These are detected when they reach a scintillator material in the scanning device, creating a burst of light which is detected by photomultiplier tubes. The technique depends on simultaneous or coincident detection of the pair of photons; photons which do not arrive in pairs (i.e., within a few nanoseconds) are ignored.

Answer 2

HELLO, my name is helga from sweden i think you switch the machine on after putting a body init.

Answer 3

they get a body then turn the PET machine on...