Radiation Safety and Biology
The spontaneous emission of particles or energy from an unstable atomic nucleus in an effort to attain stability.
What is radioactivity? (or radioactive decay)
Positioned in the outermost shell of an atom, these specific electrons determine its chemical valence and bonding behavior.
What are valence electrons?
The specific component of the X-ray tube that serves as the negative electrode and contains the filament wires.
What is the cathode?
This primary x-ray beam interaction involves total absorption of the incident photon, driving a inner-shell electron out of its orbit.
What is the photoelectric effect?
Any undesirable optical density or anomaly on a finished radiograph that does not correspond to the actual anatomical structures being imaged.
What is an artifact?
This specific term describes the process where an atom gains or loses an electron, creating a charged particle pair.
What is ionization?
This unit of energy represents the amount of kinetic energy gained by a single electron accelerating through an electric potential difference of one volt.
What is an electron volt (eV)?
This target element is favored in diagnostic X-ray tubes due to its exceptionally high melting point and atomic number of 74.
What is tungsten?
The phenomenon responsible for film fog or image degradation, caused by photons changing direction after colliding with outer-shell electrons.
What is Compton scattering?
This filtration component is intentionally added to the X-ray tube housing to harden the beam by removing low-energy, non-diagnostic photons.
What is aluminum filtration? (or inherent/added filtration)
Unlike alpha or beta particles, these highly penetrating electromagnetic waves are emitted from the nucleus of a radioactive
What are gamma rays?
Atoms that share the exact same number of protons but differ in their neutral nucleon count.
What are isotopes?
Meaning "braking radiation," this type of interaction occurs when a projectile electron is slowed down and deflected by the nuclear field of a target atom.
What is Bremsstrahlung radiation?
This device is placed between the patient and the image receptor to absorb scattered radiation before it can degrade image contrast.
What is a grid?
The ability of an imaging system to distinctly record two separate structures placed closely together.
What is spatial resolution?
This type of radiation effect follows a linear, non-threshold dose-response relationship, meaning any dose—no matter how small—carries a proportional risk of causing a random modification like cancer or genetic mutations.
What is a stochastic effect?
According to quantum mechanics and the Bohr model, this formula determines the maximum number of electrons that can occupy any given principal electron shell (n).
What is 2n^2?
This specialized circuit component permits electrons to flow in only one direction, effectively converting alternating current (AC) into the direct current (DC) necessary for stable x-ray production.
What is a rectifier?
This geometric property describes the absolute area of the x-ray tube target that is physically struck by the electron stream, which is always larger than the effective focal spot.
What is the actual focal spot?
This critical quality control measurement evaluates whether sequential exposures made at the exact same mA, time, and kVp settings yield perfectly matching radiation outputs.
What is exposure reproducibility?
The specific traditional or SI unit used to quantify occupational radiation exposure by factoring in the biological effectiveness of different types of radiation on human tissue.
What is the Rem (or Sievert)
This type of isobar specifically shares the exact same atomic number and mass number, but exists in a temporary, hyper-energetic excited state within the nucleus.
What is an isomer?
The specific phenomenon where a cloud of boiled-off electrons builds up around the filament, creating a negative charge that temporarily limits further thermionic emission.
What is the space charge effect?
This specific type of mathematical expression or function is used to calculate and visually plot the ratio of recorded image contrast relative to the true subject contrast across varying spatial frequencies.
What is the Modulation Transfer Function (MTF)?
This classic processing artifact presents as sharp, tree-branch-like black lines on a film radiograph, typically caused by low humidity levels in the darkroom.
What is a static electricity artifact?