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
Mod 1,2 4,6,9 videos
Imaging 2. Videos for midterm
| Question | Answer |
|---|---|
| ______ of a DR image is equal to the term "density" used to describe appearance of analog images. | brightness |
| ______ is a phosphor used for intensifying screens | calcium tungstate |
| _______ measures amount of exposure needed to achieve a specific density | relative speed |
| Decrease exposure level needed to achieve optical density reflects a/an ______ in receptor speed | increase |
| Direct exposure film has a _____ silver content than film used with intensifying screens | higher |
| Term to describe speed of a digital imaging system | speed class |
| Accurately create output signal that matches the input is called | DQE |
| Portion of TFT that collects individual electrons? | TFT |
| Matrix is composed of _____ | dels |
| # of electrons deposited in the DEL corresponds to the amount of .....? | radiation that strikes each area |
| Gas filled CT detectors have a _____ acceptance angle than scintillator based detectors. | smaller |
| Receptor with _____ DQE can produce optimal images with less radiation exposure | highest |
| Increased absorption efficiency has what effect on the DQE of a receptor? | increases the DQE of the receptor |
| Spatial resolution can be measured with _____/mm or ____/mm | cycles/mm or lp/mm |
| Increasing sampling frequency means what | more samples are taken per given unit of measurement |
| Greater the sampling frequency, the ____ info is extracted from the IR | more |
| Dynamic range is the IR's ability.... | to respond to exposure |
| Range of exposures that will produce an optimal image is termed | exposure latitude |
| Area of geometric blur surrounding the edges of an object is | penumbra |
| _____ phosphor gives off light photons that strike the photocathode, causing electrons to be _____. These electrons strike the ____ pohophor, causing _____ to be emitted. | input, released. Output, light photons emitted. |
| Why do LCD monitors excel over cathode ray tube displays? | They consume less energy and have better spatial resolution |
| Workstation LCD display have a much _____ luminance than traditional viewbow illuminators. | lower |
| Contrast capability of a monitor controls the ability of users to see ____ and ____ in a display image | lines and fine structures |
| Modality worklist should include what 3 things? | modality, exam, pt location |
| Adding black borders to display is called | shuttering |
| pixel value manipulation to change the visual appearance is called | edge enhancement |
| ___ is a conventional measurement unit for dose equivalent when measuring radiation | REM |
| _______ attach to the collimator and cast a shadow on the patient over the area where no radiation will be directed. They dont need touch the patient | shadow shields |
| PBL is what | positive beam limitation. auto collimation |
| Adjusting the image data to match the acceptable display data for a particular anatomical structure is known as | automatic rescaling |
| Using ____ to adjust for grid ratio increase in DR is a viable way to adjust technique without affecting image quality | kVp |
| Image noise limits the ______ of operation | speed class |
| speed class of operation for analog IR is ___. | fixed |
| Increasing kVp has what effect on the number of x-rays that the tube emits? | increases the #. |
| Primary reason for filtration? | decreasing patient dose |
| doubling distance reduces exposure by how much? | 1/4 |
| Why does beam loose intensity traveling to IR? | divergence (NOT attenuation!) |
| Using tighter collimation will reduce "undercutting"? T or F | true |
| Grids reduce the amount of scattered radiation produced. T or F? | False. They reduce the amount of scattered radiation reaching the IR, not the PRODUCTION of scatter |
| Grids main purpose is | improve contrast |
| Grids transmit 90% of primary beam. T or F? | False. 60% |
| Gridlines are less of a problem in DR than in anolog. T or F | false |
| Grid cut off _______ the amount of radiation reaching the IR. | decreases |
| Moire pattern occurs more often when using ____ dimension grids than when using ____. | short, long |
| ____ side of tube is the more intense side. | cathode |
| Compton scatter interactions take place between x-ray and _____ shell e-. | outer shell e- |
Created by:
Zoest35
Popular Radiology sets