Nuclear Medicine Exam Questions Nuclides with the same atomic number but different numbers of neutrons are called answer Isotopes Two nuclides with the same atomic numbers are called answer Isobars Two nuclides with the same number of neutrons but different atomic numbers are called answer Isotones What is a radionuclide answer A nuclide that emits particular or photon energy to achieve a more stable energy state Another name for a helium ion containing two protons and two neutrons is answer an alpha particle What is a beta particle answer An electron Why are alpha particles and beta particles not used for imaging answer They do not exit the body efficiently and thus are not detected What ratio of protons to neutrons favors beta decay answer A low proton to neutron ratio as compared with stable nuclei What two particles are emitted from the nucleus during beta decay answer A beta particle electron and an antineutrino What is the relationship between the mean energy of beta spectrum answer The mean energy is approximately one third of the maximum energy What ratio of protons to neutrons favors positron decay answer A high proton to neutron ratio What particles are released from the nucleus during positron decay answer A positron antielectron and Neutrino What is the minimum amount of nuclear energy required for positron decay answer 1 02MeV What is the fate of a positron answer To travel a short distance combine with an electron and be annihilated When a positron is annihilated via combination with an electron the result is the production of answer Two nearly opposed 511 keV photons What ratio of protons to neutrons favors electron capture decay answer A high proton to neutron ratio What particle is released from the nucleus during electron capture decay answer A neutrino What is released from the nucleus during isometric transition answer Gama rays Other than wavelength frequency and energy intensity the fundamental difference between X rays and gamma rays is answer that x rays are produced from energy released due to changes in the quantum levels values of orbital electrons of an atom while gamma rays are produced from energy shifts in the nucleus When energy from a nuclear transition results in the emission of an orbital electron rather than a gamma ray this process is called answer internal conversion Internal conversion electrons increase the radiation dose to the patient because answer Energy from the electron is absorbed within the patients body When energy from an orbital transition results in the emission of an orbital electron rather than an X ray the electron is called answer An Auger electron What does the term Metastable mean answer When an isomeric state is long lived longer After an electron is ejected from an inner shell orbital what occurs answer Outer shell electrons release energy by moving to now unoccupied less energic inner orbitals the energy released by this transition is termed characteristic of x ray radiation What are the two methods used to create synthetically radioactive materials answer Radioactive materials are produced by bombarding a target material with either ions or with neutrons A us used to bombard elements with neutrons answer nuclear reactor An is used to bombard elements with protons answer accelerator linear or cyclotron Name the 5 common cyclotron produced radionuclides used in nuclear medicine answer In111 I123 Ga67 F18 an Tl201 What is a carrier free radioisotope answer A radioisotope that does not contain any nonradioactive species What does the term activity mean answer The rate of disintegration of a radionuclide The unit of radioactivty equal to 3 7 x 10 10 disintergrations per second called answer The curie Ci What is a becquerel Bq answer The derived unit of radioactivity used by modern metric system the SI is called the becquerel One becquerel is equal to one disintegration per second or 2 7027x10 11 Ci A 1 millicurie dose of radiopharmaceutical is equal to how many becquerels answer 37 million 37MBq What does the term specific activity mean answer Specific activity refers to the ratio of activity per unit mass The time it takes a radionuclide to decay to one half of its original activityis called its answer physical half life What is the relationship between physical half life and the decay constant answer Their product equals 0 693 The time required for a substance in the body to be reduced to half its concentration via biological excretion or metabolism is called answer biological half life Which type pf half life refers to the overall loss of radioactivity from the body due to physical and biological decay answer the effective half life What is the relationship between effective hald life physical half life and biological half life answer 1 physical half life 1 biological half life 1 effective half life A radiopharmaceutical with a 6hr physical half life and a 3hr biological half life has an effective half life of answer 2 hours A common type of transient equilibrium is a answer Mo99 Tc99m When I daughter radionuclide has a half life longer than that of a parent there is equilibrium answer no When a parent half life is much longer than that of a daughter there is equilibrium answer secular What are the components of Mo99 Tc99m generator systems answer Alumina column loaded with Mo99 an eluting solvent an evacuated collecting vial and shielding What is the half life of Mo99 answer 2 8days 66hrs Maximum buildup of Tc99m in a Mo Tc99m generator system occurs after hours answer 23 hours How is a Mo99 Tc99m generator system eluted answer Tc99m is removed by passing saline through the column What does the term breakthrough mean when applied to a radionuclide generator system answer A breakthrough occurs when some parent nuclide elutes off the column along with a daughter nuclide What are the major emissions of Tc99m answer 140 keV photons By what method does Tc99m decay answer Isometric transition What is the half life of Tc99m answer 6hours What are the possible valence states of Tc99m answer 8 oxidation states from 1 to 7 What is the valence state and chemical for of Tc99m eluted from a generator answer In per technetate TcO4 1 Tc is in the 7 oxidation state Tc99O 4 must first be to a valence state of 4 prior to incorporation into most chelates answer reduced Reduction of technetium in commercial radiopharmaceutical kits is generally achieved with answer stannous tin II ion is the single radiopharmaceutical in which technetium