radionuclide (redirected from Unstable isotope)

radionuclide /ra·dio·nu·clide/ (-noo´klīd) a nuclide that disintegrates with the emission of corpuscular or electromagnetic radiations.

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ra·di·o·nu·clide (rd--nkld)

n.

A nuclide that has artificial or natural origin and that exhibits radioactivity.

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Radionuclide

A chemical substance, called an isotope, that exhibits radioactivity. A gamma camera, used in nuclear medicine procedures, will pick up the radioactive signals as the substance gathers in an organ or tissue. They are sometimes referred to as tracers.

Mentioned in: Bone Nuclear Medicine Scan, Gallium Scan of the Body, Liver Nuclear Medicine Scan, Thyroid Nuclear Medicine Scan

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radionuclide

[-no̅o̅′klīd]

Etymology: L, radiare + nucleus, nut kernel

an isotope that undergoes radioactive decay. Any element with an excess of either neutrons or protons in the nucleus is unstable and tends toward radioactive decay, with the emission of energy that may be measurable with a detector. The processes of radioactive decay include beta particle emission, electron capture, isomeric transition, and positron emission. Positron-emitting radionuclides are important in positron emission tomography and in medical research. Radionuclides used in scintigraphy include ¹²³I, ¹³¹I, ¹¹¹In, ⁷⁵Se, ^99mTc, and ²⁰¹Tl. Radionuclides of cobalt, iodine, phosphorus, strontium, and other elements are used for treatment of tumors and cancers and for nuclear imaging of internal parts of the body. See also nuclear scanning.

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radionuclide (rā´dēōnoo´klīd),

n an unstable or radioactive type of atom characterized by the constitution of its nucleus and capable of existing for a measurable time. The nuclear constitution is specified by the number of protons
(A), number of neutrons
(N), and energy content, or alternatively by the atomic number
(Z), mass number
(A − N + Z), and atomic mass.

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radionuclide

a radioactive nuclide; one that disintegrates with the emission of corpuscular or electromagnetic radiations. Used in diagnosis for whole body or individual organ scanning. See also radioactive isotope, nuclide.

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radionuclide

Radioactive isotope, radioisotope Radiation physics A nuclide with an unstable neutron to proton ratio, which undergoes radioactive decay; an artificial or natural nuclide with an unstable nucleus, that decays spontaneously, emitting electrons–β-particles or protons–α-particles and γ-radiation, ultimately achieving nuclear stability; RNs are used as in vivo or in vitro labels, for RT, or as sources of energy