Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
RADT 465: QC
| Question | Answer |
|---|---|
| Characteristics determining image quality: visibility factors | Brightness & grayscale/contrast p.314 |
| Characteristics determining image quality: Geometric factors | Spatial resolution & distortion p.314 |
| The function of contrast is to make details ____ | visible p.314 |
| HIGH contrast is ____ scale contrast | short - few, very different, images/tissue densities p.314 |
| LOW contrast is ____ scale contrast | Long - many similar image/tissue densities p.314 |
| Any combination of mA and exposure time that will produce a particular "mAs" will produce identical receptor exposure is know as | Reciprocity law - if 10 mas is required to produce a given receptor exposure, all combinations should produce identical results: 100mA and 100ms, 200mA and 50ms, 300mA and 33ms. p.315 |
| mAs is ____ proportional to receptor exposure | directly p.315 |
| mAs is a _____ factor regulating the number of of photons | quantitative p.315 |
| T/F: mAs has lots of impact on contrast | F: Kvp p.315 |
| _____ contrast refers to body tissue densities and their differential absorption of the x ray beam | subject p.315 |
| As distance between the x ray tube and the IR (SID) increases, exposure rate decreases according to the __________ law | inverse square law p.315 |
| Kv affects both ___ (energy/wavelength) and ___ of the x ray beam | quality and quantity p.317 |
| Kv regulates beam _______ and has a significant impact on image contrast in analog imaging | quality/penetration p.317 |
| Whatare some factors that determine production of scattered radiation | Field size/beam restriction, kilovoltage, thickness/volume and density of tissues p.318 |
| scatter radiation carries no useful information but adds ___ in the form of ___, thereby impairing visibility of detail | noise, fog p.318 |
| As the size of the x ray field is reduced, there are less area and tissue volume for ______ to be generated | scatter radiation - reducing the field size takes the low energy photons out and only allows the high energy photons to get through causing less scatter radiation p. 320 |
| scatter radiation i s a result of x ray photon interaction with tissue atoms via ____ scatter processes and adds quality degrading fog to the radiographic image | Compton p.320 |
| what are the 2 RADIATION PRODUCTION interactions | bremsstrahlung & characteristic (worksheet) |
| T/F: all radiation production interactions start with an electron | T: not a photon (worksheet) |
| incoming electrons slows around the nucleus in the target atom; what interaction | bremsstrahlung (worksheet) |
| incoming electrons interact with any inner electron in the target atom | characteristic - really want electron to react with the K (most inner shell) to get the most energy x ray (worksheet) |
| filtration _____ overall average energy of the x ray beam | increases - taking out the low energy photons p.328 |
| filtration has a total filtration of _____ mm Al equivalent | 2.5 mm p328 |
| Beam restriction ____ the production of scattered radiation and, consequently, _____ receptor exposure | reduces, decreases p.332 |
| what is the percentage for a single phase? | 100% p.333 |
| what is the percentage for a three-phase 6 pulse? | 13% p.333 |
| what is the percentage for a three-phase 12 pulse? | 4% p.333 |
| what is the percentage for a high frequency? | less than 1% p.333 |
| ______ is the ability to manipulate the image after exposure | postprocessing p.334 |
| a ______ is a graphic representation of pixel value distribution demonstrating the number of pixels and their value | histogram - remember all the information of the anatomy is between s1 and s2. there are 3 different types of histograms. p.334 |
| what are the 2 types of AECs | phototimer & ionization chamber pp.337 |
| ______ identifies grayscale values | bit depth p.337 |
| As SNR _____, noise in the form of graininess ______ | decreases, increases p.337 |
| _____ is used to automatically regulate the amount of ionizing radiation delivered through the anatomic part to the IR | AEC p.337 |
| ____ utilizes selection of anatomic part, rather than selection of specific technical factors. | APR p.341 |
| ________ is the term used to describe the IR's impact on image detail | spacial resolution p.348 |
| Digital image resolution improves with .... | smaller pixel size, smaller pixel pitch, larger image matrix, greater pixel density p.348 |
| spatial resolution factors for direct digital (DR) | pixel pitch & DEL size of the TFT p.348 |
| spatial resolution factors for indirect digital (CR) | pixel pitch & sampling frequency p348 |
| DQE stands for | detective quantum efficiency p.349 |
| As the matrix size is _____, there are more and smaller pixels in the matrix, therefore improved ___________ | increased, spatial resolution p.349 |
| _____ describes the percentage of incoming x ray photons that are deteced and absorbed by the detector for transformation to the x ray image | DQE p.349 |
| how can does one shorten the life span of the x ray tube? | delivering heat to the x ray tube in a short period of time p.358 |
| _____ focal spot size = ____ blur = ____ detail | increase, increase,, decrease p.359 |
| The use of a small/large focal spot size improves spatial resolution but generates more heat at the anode | small p.359 |
| CR resolution is improved by (3 things) | smaller barium fluorohalide phosphors, narrow width laser beam, larger monitor matrix. p.370 |
| ___ is conversted to an electrical signal and transferred to the ADC; digital data are then transferred to DAC | PSL p.375 |
| ____ is the most typical in extremity imaging | PSP p.375 |
| ____s function to manipulate grayscale values to provide the appropriate grayscale rendition | LUTs p.378 |
| _________ compensates for too little/too great an exposure | automatic rescaling p.378 |
| low frequency, ___ wavelength, __ energy | long, low p.389 |
| high frequency, ___ wavelength, __ energy | short, high p.389 |
| X ray photons can (3 things) | pass through part, be absorbed by the part, scatter within the part p.391 |
| ______ change mechanical energy to electrical energy | Generators p.394 |
| ______ change electrical energy to mechanical energy | motors p.394 |
| AC consists of _____ waves | sinusoidal p.395 |
| X ray tube consits of what 3 things | anode (positive electrode), cathode (negative electrode), glass envelope (vacuum) p.408 |
| The anode has a ____ disk with beveled edge, ____ alloy focal track, ____ stem for support for anode disk | Graphite/molybdenum, tungsten/rhenium, molybdenum. p.408 |
| The induction motor does what 3 things | rotates the anode, stator (outside the glass envelope), rotor (inside glass envelope). p.408 |
Created by:
2024767030873700
Popular Radiology sets