Summary:
Positron emission tomography (PET) imaging devices were
first developed in the 1970. In the last thirty years PET
imaging has been extensively used in research, but only in
the last few years the technology has become more widely
available for clinical applications. Most of the early works
with PET focused on brain metabolism, partly because of
the smaller size of detector needed to study head. With the
introduction of improved instruments and suitable
radionuclide, applications in oncology have developed into
the major clinical uses of PET. Myocardial viability is
usually assessed using perfusion studies with Signal photon
emission computed tomography (SPECT) but in case of
inconclusive result, metabolic assessment with short-lived
PET tracers may be more decisive. PET allows study of body
function; it helps detection of alterations in biochemical
processes that suggest disease before changes in anatomy
are apparent with other imaging tests, such as computed
tomography (CT) or magnetic resonance imaging (MRI).