the highest energy level of photons in the x-ray beam, equal to the highest voltage established across the x-ray tube
What is kVp?
the product of electron tube current and the amount of time in seconds that the x-ray tube is activated
What is mAs?
photons that sometimes interact with atoms of a patient such that they give up all of their energy and cease to exist
What is absorption?
two materials that comprise the anode
What are tungsten and rhenium?
atomic number of tungsten
What is 74?
the 3 ways x-rays interact with biologic tissue
What is absorbed, scattered, and pass through without interaction?
produced when a stream of very energetic electrons bombards a positively charged target in a highly evacuated glass tube
What is a diagnostic x-ray beam?
photons that interact with atoms of the patient but only surrender part of their energy; they will continue to exist but will emerge from the interaction at a different angle
What is scatter?
two reasons tungsten and rhenium are chosen for anode
What are they have high melting points and high atomic numbers?
particles associated with electromagnetic radiation that have neither mass nor electric charge and travel at the speed of light
What are photons?
In the tube, this acts as a filter by removing diagnostically useless, very-low-energy x-rays; x-ray beam exits the tube through this
What is the glass window?
Material placed within the collimator assembly to intercept the emerging x-rays before they reach the patient; this material “hardens” the x-ray beam (i.e., raises its effective energy) by removing low-energy components that would serve only to increase patient dose
What is aluminum?
combination of the x-ray tube glass window and the added aluminum placed within the collimator
What is inherent filtration?
digital device that can convert the spatial pattern of the photons that emerge from the patient into electrical signal values that can be stored in a computer and displayed as an image
What is an image receptor?
amount of energy absorbed per unit mass
What is absorbed dose?
For a typical diagnostic x-ray unit, the mean photon energy in the x-ray beam is about ___________ the energy of the most energetic photon
What is one-third?
photons that either did not interact with the atoms of the patient or else interacted through scatter but still struck the receptor, although at a different spot than they would have struck the image receptor if they had not interacted
What are transmitted photons?
photons that have undergone either absorption or scatter and do not strike the image receptor
What is attenuation?
photons pass through the patient without interacting with the atoms of the patient
What are direct transmission photons?
photons that interacted with atoms of the patient, but still happened to strike the image receptor
What are indirect transmission photons?
Indirect transmission photons are always the result of scatter: Yes or No?
What is Yes?
Indirect transmission photons are always present in radiography: Yes or No?
What is Yes?
X-ray photons after exiting the tube and before interacting with human tissue
What is primary radiation?
X-ray photons exiting the patient and striking the image receptor
What is exit (image-formation) radiation?
any process decreasing the intensity of the primary photon beam; refers to both absorption and scatter processes that prevent photons from reaching a predefined location
What is attenuation?