| Question | Answer |
| define extrafocal radiation. | radiation that hits just outside the focal spot and still exits the window. |
| what are contained in the focusing cup during the production of x-rays? | electrons |
| can x-rays be focused with a lens? | no |
| define density. | overall blackening of the x-ray image. |
| what controls filament circuit and measures tube current? | mA |
| define primary radiation. | useful beam from the window. |
| what is the purpose of a grid? | to decrease secondary and scatter radiation. |
| x-rays are high energy waves called photons. true or false? | true |
| How do you get mAs? | mA x time = mAs |
| how many focal spots are on the target in the anode? | two. one large and one small. |
| x-rays are perfectly safe, true or false? | false, they have a biologic effect. |
| define isotropic. | equal all the way around. |
| What controls quantity? | mA |
| a grid increases or decreases the amount of overall radiation to the IR? | decreases. |
| what is the function of the tube housing? | provide support for the x-ray tube.
protection from leakage radiation.
dissipate heat away from the tube.
protection for high voltage cables. |
| define exit/remnant radiation. | radiation it leaves the patient's body. |
| how many filaments are found in the cathode? | two. one small and one large |
| scatter and secondary radiation have a lower energy level. Is it a longer or a shorter wavelength? | longer. |
| Name the two main components of an x-ray tube | anode and cathode |
| true of false: since x-rays are waves, the do not travel in straight lines. | false |
| what is the difference between scatter and secondary radiation? | scatter strikes an OUTER shell electron.
secondary interacts with an INNER shell electron. |
| the process of boiling off of electrons is called what? | thermionic emission. |
| what alters x-ray beam wavelength? | kVp |
| a filter absorbs long or short wave radiation? | long-wave radiation. |
| If the OID increases, what happens to exposure? | decreases. |
| define radiolucent. | substance that absorbs less radiation. |
| how fast do x-rays travel? | at the speed of light |
| what two components make up the cathode? | filament and focusing cup |
| compare filament and tube current. | filament current = high amps and low voltage.
tube current = low amps and high voltage. |
| Increasing atomic number increases/decreases attenuation? | increases. |
| define OID | object to IR distance. |
| What two things are produced by x-ray production? | heat and x-rays |
| what is the source of electrons in the x-ray tube? | cathode |
| a filter increases or decreases the amount of overall radiation to the IR? | decreases. |
| define radiopaque. | substance that absorbs more radiation. |
| what factors affect contrast? | kVp
beam restriction (collimation, coning)
fog (lengthens scale)
filtration (decreases contrast)
patient (more tissue increases secondary and scatter and decreases contrast)
grid (increases contrast) |
| define leakage radiation. | any radiation emanating from the tube housing. |
| What controls quality? | kVp |
| Name the three things x-rays can do. | transmit, absorb, or scatter |
| define SID | source to IR distance. |
