| A | B |
|---|
| Charge of a proton. | Positive |
| Charge of an electron. | Negative |
| Determines the identity of an element. | Number of protons |
| Atom that gains or loses an electron. | Ion |
| Atom with same number of protons, but different number of neutrons. | Isotope |
| Binding energy is stronger_____. | Closer to the nucleus |
| Binding energy is weaker _____. | Farther from the nucleus |
| How are frequency and wavelength related? | Inversely |
| How are photon energy and frequency related? | Directly proportional |
| What are the prime factors? | kVp, mAs and distance |
| What prime factor governs x-ray quantity? | mAs |
| What prime factor governs x-ray quality? | kVp |
| How are mAs and exposure related? | Directly proportional |
| Contrast is controlled by _____. | kVp |
| Density is primarily controlled by _____. | mAs |
| Define the reciprocity law. | Density on x-ray remains unchanged as long a the intensity and duration of the exposure remains unchanged. |
| Define inverse square law. | Intensity of radiation at a given distance is inversely proportional to the square of the distance. |
| Explain the 15% rule. | A 15% increase in kVp will double the exposure, and a 15% decrease in kVp will halve the exposure. |
| When is the density maintenance formula used? | Used to compensate for density changes when distance is changed. |
| 3 ways amount of scatter can be reduced. | Beam restriction, reduce kVp, use grids, decrease amount of irradiated tissue. |
| How does beam restriction affect patient dose? | It reduces it. |
| What patient factors contribute to the production of scatter? | Volume and atomic number of material. |
| When kVp increases, what happens to scatter? | It increases |
| What interaction produces the most scatter radiation? | Compton |
| Smaller fields sizes produce _____ scatter. | Less |
| Name the beam restrictors. | Diaphragms, cone, cylinders, collimators |
| When kVp is decreased, what happens to contrast? | It is higher, short scale. |
| How does scatter affect density? | It increases it. |
| Most common type of beam restrictor. | Collimator |
| Which shutters reduce penumbra along the periphery of the beam? | Bottom |
| Which shutters reduce off-focus radiation. | Top |
| The source of most scatter. | The patient |
| Reduction of the number of x-rays after it passes through a given thickness of material. | Attenuation |
| 2 factors that increase attenuation. | Amount and type of irradiated tissue. |
| 4 substances in body that account for most of x-ray absorption. | Bone, air, fat, muscle |
| Substance in the body that attenuates most. | Bone |
| Substance in the body that attenuates least. | Air |
| Define subject contrast. | Degree of differential absorption from different tissues in the patient. |
| Define subject density. | The impact the patient has on density. |
| What device increases contrast by absorbing scatter? | A grid |
| When using a grid what is the minimum kVp used? | 60 |
| When using a grid, what is the minimum body part thickness? | 10 cm |
| What is the grid ratio formula? | Height/distance |
| Define grid frequency. | The number of lines per inch or centimeter. |
| Higher grid ratios remove _____ scatter. | More |
| A lower ratio grid will remove _____ scatter than a higher ratio. | Less |
| When the tube is angled across the long axis of the grid strips. | Off-level grid error. |
| When the tube is not centered to the middle of a focused grid. | Off-center grid error |
| What type of grid has grid lines that matches the divergence of the beam? | Focused |
| When a grid is used at the wrong distance. | Off-focus grid error |
| Name the layers of film. | Polyester base, adhesive, emulsion, supercoat. |
| What is contained in the emulsion of film? | Gelatin and silver halide crystals |
| Most commonly used silver halide. | Silver bromide |
| What is the purpose of a sensitivity speck? | To attract free silver ions |
| Film is exposed primarily by _____ photons. | Light |
| What happens to resolution as film crystal size decreases. | It increases |
| At what temperature should film be stored? | 68 degrees F |
| When storing film, what should the humidity level be? | 30 to 60% |
| Scratches on film caused by turn around assembly and are parallel to the direction of film travel. | Guide shoe marks |
| Black lines on film at 3.14 inch intervals caused by dirt or stain on the roller. | Pi lines |
| How will chemical fog look on a film? | Like light or radiation fog; dull gray, yellow, green, blue or purple. |
| Artifact when chemicals run down the film. | Dichroic stain / curtain effect |
| What reduces patient dose, produces light and amplifies the incoming x-ray photon beam? | Screens |
| 99% of the latent image is produce by _____ photons. | Light |
| The ability of the phosphor to emit as much light per x-ray photon interaction as possible is: | Screen speed |
| When an insufficient quantity of photons strikes the intensifying screen it is called ______. | Quantum mottle |
| How is quantum mottle eliminated? | Increase mAs |
| The ability of a material to emit light in response to excitation. | Luminescence |
| When light is emitted from a phosphor instantaneously. | Fluorescence |
| When light emitted from a phosphor is delayed. | Phosphorescence |
| What 3 things control intensifying screen resolution? | Crystal size, layer thickness, concentration of crystals |
| Fast screen have _____ resolution. | Lower |
| At what stage in film processing does the latent image become visible? | Development |
| WHat agent bonds with unexposed silver halides? | Clearing agent |
| What needs to happen before a silver halide crystal can be developed? | It must have more than 3 silver atoms on its sensitivity speck. |
| When is a stable black metallic silver atom formed? | When a positive silver ion obtains an electron. |
| What is the purpose of radiographic processing? | To convert the latent image into the visible image. |
| What processor solution is most affected by contamination? | Developer |
| A step wedge is also known as: | A penetrometer |
| Name the 5 parts of the D log E curve. | Base plus fog, toe, straight line portion, shoulder, Dmax |
| On what part of the D log E curve is the diagnostic information found? | Straight line portion. |
| As the slope of the straight line decreases, what happens to contrast? | It decreases |
| What part of the D log E curve represents density at no exposure? | Base plus fog |
| I know all the formulas for this class and will be able to solve problems on the final. | Absolutely |
