Positron emission tomography Essay Example | Topics and Well Written Essays - 2500 words

Positron emission tomography - Essay Example Isotopes with the tendency to radioactivity refer to atoms with an unstable nucleus. The inner core, which consists of the nucleus, has unbalanced energy. The dense package of neutron and proton makes the nucleus unstable. The lack of stability is the basis for the decomposition process. Therefore, through decomposition, the nuclei transform its configuration and components to a less strength and steady condition. This decomposition obeys the exponential law, which states ‘the number of decomposition per second is always equivalent to the amount of the undecayed nuclei available.' The law is also applicable to the rate of decay (activity). The decay depends on the half-life of the nuclide. Half-life is the duration/time that a nucleus takes to be halved.Positrons refer to the subatomic molecules that are equal in mass to an electron with characteristic of carrying a positive charge. When the positron decay (ÃŽ ²+), its nuclei changes one of the core protons (p) to a neutron (n) , while emitting positron (ÃŽ ²+) to attain a positively charged nature referred to as neutrino (ÃŽ ½).Upon the release from the initial nucleus, the high positron moves across a few millimeters through the tissue until it attains thermalization, during the acquisition of thermal energy, the positrons arrive at thermal energies. They begin connecting with electrons either through annihilation that produce two 511 keV photons to take anti-parallel positrons frame or through development of the hydrogen.