front 1 Particles associated with electromagnetic radiation that have no mass or electric charge are:
| back 1 x-ray photons |
front 2 Coherent scattering is most likely to occur ____________, even though some of this unmodified scattering occurs throughout the diagnostic range and may result in small amounts of radiographic fog.
| back 2 below 10 keV |
front 3 Which of the following is not a type of interaction between x-radiation and biologic matter?
| back 3 Bremsstrahlung |
front 4 The symbol Z indicates the:
| back 4 atomic number of an atom |
front 5 In photoelectric absorption to dislodge an inner-shell electron from its atomic orbit, the incoming x-ray photon must be able to transfer a quantity of energy:
| back 5 as large as or larger than the amount of energy that binds the electron in its orbit |
front 6 Which of the following interactions between photons and matter involves a matter-antimatter annihilation reaction?
| back 6 Pair production |
front 7 The probability of occurrence of photoelectric absorption _________ as the energy of the incident photon decreases and the atomic number of the irradiated atoms _________.
| back 7 increases markedly, increases |
front 8 Which of the following terms refers to the radiation that occurs when an electron drops down from an outer orbit to fill a vacancy in an inner orbit of the parent atom?
| back 8 Characteristic radiation |
front 9 Fluorescent radiation is also known as:
| back 9 characteristic radiation |
front 10 What is the effective atomic number of compact bone?
| back 10 13.8 |
front 11 Which of the following is not another term for coherent scattering?
| back 11 Characteristic |
front 12 Which of the following are byproducts of photoelectric absorption?
| back 12 Photoelectron and characteristic photon |
front 13 Which two interactions between x-radiation and matter may result in the production of small-angle scatter?
| back 13 Coherent scattering and Compton scattering |
front 14 Which of the following particles is considered to be a form of antimatter?
| back 14 Positron |
front 15 Which of the following interactions results in the conversion of matter into energy?
| back 15 Annihilation reaction |
front 16 Compton scattering is synonymous with:
| back 16 incoherent scattering |
front 17 During the process of coherent scattering, the incident x-ray photon interacts with a(n):
| back 17 atom transferring its energy by causing some or all of the electrons of the atom to vibrate momentarily and radiate energy in the form of electromagnetic waves |
front 18 What is the term for the number of x-rays emitted per inner-shell vacancy during the process of photoelectric absorption?
| back 18 Fluorescent yield |
front 19 Which of the following results in all-directional scatter?
| back 19 Compton interaction |
front 20 Annihilation radiation is used in which of the following modalities?
| back 20 Positron emission tomography (PET) |
front 21 The x-ray photon energy required to initiate pair production is:
| back 21 1.022 MeV |
front 22 Differences in density level between radiographic images of adjacent structures as seen in a completed radiograph define:
| back 22 radiographic contrast |
front 23 Radiographic density is:
| back 23 defined as the degree of overall blackening on a completed radiograph |
front 24 When a vacancy exists in an inner electron shell of an atom (as a result of photoelectric effect, Compton scattering, or bombardment by other electrons), the energy liberated when this vacancy is filled, instead of emerging from the atom as fluorescent radiation, can be transferred to another electron of the atom, thereby ejecting the electron. Such an emitted electron is called a(n) _____ electron.
| back 24 Auger |
front 25 X-rays are carriers of:
| back 25 manmade, electromagnetic energy |