Radiologic Sciences Questions with Correct Solutions | From my Notes

ALPHA PARTICLE - nucleus of a helium atom, consisting of 2 protons and 2 neutrons, having a positive charge of 2. ANNIHILATION - total transformation of matter into energy; occurs after the anti-matter positron collides with an electron. ATOM - smallest division of an element that exhibits all the properties and characteristic of the element. BECQUEREL (Bq) - unit of activity in the International System. 1 Bq = 1 dps BETA PARTICLE - electron whose point of origin is the nucleus; electron originating in the nucleus by way of decay of a neutron into a proton and an electron BGO SCINTILLATOR - Bismuth germanate (Bi4Ge3O12) scintillator with efficiency twice that of sodium iodide. COLD SPOT - lack of radiation being received or recorded, not producing any image and resulting in an area of no, or very light, density, may be caused by disease or artifact. COLLIMATOR - shielding device used to limit the angle of entry of radiation; usually made of lead. CURIE - standard measurement for radioactive decay CYCLOTRON - device for accelerating charged particles to high energies using magnetic and oscillating electrostatic fields. DAUGHTER - element that results from the radioactive decay of a parent element. DECAY - radioactive disintegration of the nucleus of an unstable nuclide DEUTERON - ionized nucleus of heavy hydrogen (deuterium), which contains 1 proton and 1 neutron. DOSE - measure of the amount of energy deposited in a known mass of tissue from ionizing radiation. 1 rad = 10-2 joules/kg. ELECTRON - negatively charge elementary particle. EXTERNAL RADIATION DETECTOR - instrument used to determine the presence of radioactivity from the exterior. FISSION - splitting of a nucleus into two or more parts with the subsequent release of enormous amount of energy. GAMMA CAMERA - devise that uses the emission of light form a crystal struck by gamma rays to produce an image of the distribution of radioactive material in a body organ. GAMMA RAY - high energy, short wavelength EMR emanating from the nucleus of some nuclides. GROUND STATE - state of lowest energy of a system HALF-LIFE (T1/2) - term used to describe the time elapsed until some physical quantity has decreased to half of its original value. HOMEOSTASIS - state of equilibrium of the body's internal environment IN VITRO - outside a living organism IN VIVO - within a living organism ISOTOPE - nuclide of the same element with the same number of protons but different number of neutrons. ISOTROPIC - referring to uniform emission of radiation or particles in three dimensions. METASTABLE - described the excited state of a nucleus that returns to its ground state by emission of gamma ray; has a measureable lifetime. NEUTRON - electrically neutral particle found in the nucleus. NUCLEAR PARTICLE REACTOR - device to produce radioactive material by accelerating ions (e.g., electrons, protons, deuterons) to high energies and projecting them toward stable materials. Accelerators include LINAC, Cyclotron, Synchrotron, Van de Graaff accelerator and Betatron. NUCLEAR REACTOR - device that under controlled conditions is used for supporting a self-sustained nuclear reaction NUCLIDE - general term applicable to all atomic forms of element. PARENT - radionuclide that decays to a specific daughter nuclide either directly or as a member of a radioactive series. PARTICLE ACCELERATOR - device that provides the energy necessary to enable a nuclear reaction PHARMACEUTICAL - relating to a medicinal drug. PHOTOMULTIPLIER TUBE (PMT) - electronic tube that converts light photons to electrical pulses.