Computed Radiography Word Scramble
|
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
Question | Answer |
what is the purpose of the cassette? | to reduce back scatter |
the back part of the cassette has lead to reduce back scatter, what does the front(tubeside) have? | imaging plate, radiolucent |
is the image plate mounted on the front or backside of the cassette | back |
what are the layers of the cassette and imaging plate? | backing,base, antihalo reflective layer, phosphor, protective |
backing | bar code info |
base | mechanical support |
antihalo reflective layer | allows light to be reflected back (Prevents backflow) |
phosphor(active) | barium fluorohalide, Europium makes it inperfect, psp |
protective | Clean it |
once the plate is read by the laser how is it erased? | White light |
what are the guidelines about erasing | erase it twice(extra Lg patient), if 48hrs erase twice |
what window post processing can we use to change the contrast | window width |
whats another term for computed radiography | cassette based |
what is a pixel | picture element |
what is a voxel | 3D pixel |
matrix | rows or columns of pixels |
what are the 5 factors that effect spatial resolution or recorded detail? | motion blur(time),sid,oid, focal spot size, image receptor |
for better spatial resolution, do we want Large or Small pixels? | Small |
would that give you LG or SM pixel pitch? | Small |
if we have small pixels with small pixel pitch,would that allow a higher or lower pixel packing density? | higher |
if we have small pixels, would we have a LG or SM matrix | Larger |
what is the purpose of the exposure index | tells if you underexposed, or overexposed |
for the CR system we use the S Number which stands for senstivity. so at HMC what is the range of S values that are acceptable | 100-200, below 100 overexposed, over 200 make too much noise and decrease the contrast |
what is radiolucent | allows xrays to go through |
radio-opaque | blocks xrays and does not allow them through |
what is the LUT(look up table) | visible gray scale rendered image,can be adjusted by changing window width or range after initial processing. |
what is the forumla to calculate Bit depth | 2^n |
if we buy system with certain bit depth can we change it? | No |
is the graphical representation of the signal intensity per exposure to the imaging plate | histogram |
what do we call histogram with CR system | Tag |
what are some things that can cause histogram error | wrong tag,improper collimation, not centered right, lead |
what does pacs stand for | Picture Archiving and Communication System |
what does pacs do? | transport and store images |
what is the pacs system we have at HMC | DR |
what is the purpose of HL7(health level 7) | to communicate between RIS and the HIS |
what information is on the DICOM header | Patient Name, Medical Record Number, Bar coding |
what is the purpose of DICOM standards | allows us to transfer images from catapult(Tech station) to Radiologist |
what does IRD stand for | image reader device |
what does IRD do for us? | A-D Converter(Analog to digital converter)reads the plate and makes the manifest image come up on your table |
what is a latent image | image captured by the image receptor, Invisible image( after exposure, but before processing) |
once we run the CR plate throught the IRD and the image comes up on the LUT what is that image called | manifest image |
PSP | Barium fluorohalide w/ Europium |
Latent Image Formation | as the exit beam strikes phosphor, at the Europium sites electrons are given off, and the electrons go through conduction band and held at a bound state at the F-center |
what is the purpose of the low Freq scan in IRD | to set the parameters |
what is the 2nd scan that is really fast that prevents banding elements | high freq progressive |
why is High Freq scan better than Low Freq Scan | Better resolution and Contrast |
when the laser hits the Electrons in the F-center, what does that excess energy make those electrons do? | fall back onto Europium site and then give off light |
where is that light sent to in an A-D Convert | CCD, Photodiode |
types of converters in IRD | CCD,Photomultiplier tube, or photodiode |
what is the HIS at HMC | Meditech |
what is the purpose of the default pixel shifting | motion fix |
Turbid or Columnar, which is Cesium Iodide, and which has better spatial resolution | Columnar |
Turbid is in the form of what? | Powder |
what type of scintillator uses turbid | G. Oxysulfide |
which one has higher detection efficency, better absorption of xray photons so you can use less MAs | G. Oxysulfide |
what is the purpose of stiching | spine Treatment(scoliosis) |
what is the measurement of spatial resolution where it looks at the bottom information that is available in your object VS. whats actually captured | module transfer function |
whats the min freq that all scanners have to meet | nyquest |
what scan gives you better resolution and contrast | High Freq Progressive |
what is the ROI(region of Interest) | area that it is sampling |
what can we do post procedure to change density and contrast, is it direct or indirect | window width, indirect |
window level changes, is it a direct or indirect | brightness, direct |
what is any unwanted density | artifact |
how can we prevent grid aliasing or Moire | thin lines |
what type of scanning do you to prevent banding | progressive scanning |
what is the purpose of auto-rescaling | match up histogram, apporiate brightness and contrast |
what is the purpose of the detail smoothing | helps get rid of noise but gets rid of fine detail |
whats the process of equalization used for | parts with different densities |
whats the purpose of edge enhancement | artificial enchancment of the bone |
what does the fourier transformation do | change image |
what does DQE stand for | detective quantum efficency- how well scintillator picks up radiation |
what is FOV(field of View), does CR or DR have variable field of view | size of image receptor, CR |
what is brightness | blackening of image receptor or luminescent of each pixel |
what is contrast | density difference |
whats the purpose of shuttering | to reduce radiologist eye strain |
is collimation important | yes |
what type of freq or grid do we want to use to prevent grid aliasing | thin, High Freq progressive |
Created by:
johnsoni1986
Popular Radiology sets