Busy. Please wait.
Log in with Clever
or

show password
Forgot Password?

Don't have an account?  Sign up 
Sign up using Clever
or

Username is available taken
show password

Your email address is only used to allow you to reset your password. See our Privacy Policy and Terms of Service.


Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.

Imaging 2 - digital

Quiz yourself by thinking what should be in each of the black spaces below before clicking on it to display the answer.
        Help!  

Question
Answer
Physical basis for the CR image is the IP detector, which is made of a photostimulable phosphor (PSP) (3 steps):   show
🗑
show Indirect TFT and direct TFT.  
🗑
show indirect uses phosphor, direct uses a photoconductor.  
🗑
show phosphor (indirect)- convert x-ray energy into electrical through an intermediate stage of light photons, photoconductors (direct) convert energy energy directly into electrical charge without the intermediate stage.  
🗑
2 types of indirect digital detectors?   show
🗑
show indirect, CCD chip  
🗑
Which detector is not classified as a flat-panel digital detector but is available commercially?   show
🗑
show x-ray absorber, scintillator, light optics, the CCD. (which is a sensor chip.. or many...)  
🗑
What does the CCD (sensor chips) do?   show
🗑
Scintillator screen does what in CCD detectors? ****   show
🗑
show x-ray scintillator (conversion layer usually cesium iodide or gradolinium), an amorphous silicon (a-Si) photodiode flat panel layer, with a thin-film transistor (TFT) (for reader of the electrical charges by the photodiode)  
🗑
Scintillator layer used in indirect flat-panel (TFT) is usually either ___________ or ________.   show
🗑
show cesium iodide (Csi) crystals are deposited in needle like fashion, (structured phosphors)  
🗑
show gradolinium oxysulfide crystals, (turbid phosphors)  
🗑
show Csi- structured, Gradolinium- turbid  
🗑
show X-ray detection of CR is inefficient and this affects image quality and dose, Spatial resolution of CR is less than FS radiography. CR IPs can easily be damaged. CR IPs must be transported to a separate image processor for image data extraction  
🗑
(flat panel DR) Selenium drum technology developed specifically for:   show
🗑
CCD indirect digital detector order:   show
🗑
show scintillator, produce electron-hole pairs.  
🗑
show During readout, system electronics provide systematic collection of changes on each chip in a manner referred to as a “bucket brigade”. (the charge pattern from the readout of pixels is sent to the ADC for digitization)  
🗑
show The charge pattern from the readout of pixels (from the light of the scintillator falling on each pixel that produced electron-hole pairs...) is sent to the ADC for digitization. Then sent to computer for processing.  
🗑
show powdered. (this is why structured phosphor like Csi crystals are better)  
🗑
show thin-film transistor  
🗑
Indirect flat panel TFT detectors: following the x-ray scintillator (x-ray detection medium) is what?   show
🗑
Indirect flat panel TFT detectors: a-Si photodiode layer is for what?   show
🗑
Indirect flat panel TFT detectors: purpose of the capacitor?   show
🗑
show scintillator phosphor such as CsI, a-Se photoconductor to convert x-rays directly  
🗑
Indirect TFT: the purpose of the a-Si photodiode layer is ?   show
🗑
Indirect TFT: the purpose of the capacitator is ?   show
🗑
Direct TFT: the photoconductor is usually what substance?   show
🗑
Direct TFT: the photoconductor (a-Se) does what?   show
🗑
show consists of rows and columns that play a role in addressing and readout of the signal from each pixel.  
🗑
Flat panel TFT: each pixel contains what 3 things?   show
🗑
The sensing area (in each pixel of a TFT) will detect the light from the CsI scintillator in the indirect TFT detector, or in the case of a direct TFT, ______________.   show
🗑
show photodiode, storage capacitor.  
🗑
The ______________ of the pixel receives the data from the layer above it that captures x-rays that are converted to light (indirect) or electrical charges (direct).   show
🗑
Fill factor is what?   show
🗑
Fill factor is expressed how?   show
🗑
show spatial resolution and contrast resolution (detail and signal-to-noise)  
🗑
Detectors with ____ fill factors (____ sensing areas) will provide better spatial and contrast resolution.   show
🗑
Indirect TFT detectors use a light sensitive ___________ to capture light from the scintillator phophor (such as CsI) to produce _________. Direct TFT detectors use an a-Se ___________ to convert the x-rays _________.   show
🗑
show atomic number (Z#), density, and thickness of attenuating material.  
🗑
X-ray scintillators are what for indirect flat panel TFTs?   show
🗑
General operating principles/steps of indirect TFT?   show
🗑
show photons fall upon the a-Se photoconductor layered on top of a matrix of a a-Si TFT array. As xrays strike the a-Se, electral charges are created and the electrical field causes them to move towards the TFT elements where they are collected and stored.  
🗑
show initialization.  
🗑
What is exposure latitude?   show
🗑
show does not  
🗑
Raw digital data is first subject to pre-processing and presented as _______________ image.   show
🗑
After the image is presented as "for processing" image, it then undergoes digital image _____________, and the resultant image is labeled a _________________ image.   show
🗑
show post  
🗑
show flat-field image.  
🗑
You base scaling the histogram on what?   show
🗑
Third step in image processing is ___________, where the adjusted or scaled raw data values are mapped to the "for presentation" values to display an optimum image.   show
🗑
"processing optimization rules" are what   show
🗑
the ability of the imaging system to resolve fine details present in an object is called   show
🗑
3 tests to measure spatial resolution?   show
🗑
What is the modulation transfer function? ***   show
🗑
An MTF of ____ represents a perfect detector.   show
🗑
show fine details, contrast.  
🗑
show better  
🗑
High MTF value at lower spatial frequencies means that the detector provides better _____.   show
🗑
show the response of the detector to different levels of radiation exosure  
🗑
show Detective quantum efficiency. "the efficiency of a detector to convert the x-radiation signal at its entrance window into useful image signal.  
🗑
It is important to have low or high SNR?   show
🗑
show DQE= SNR 2out / SNR 2in  
🗑
A perfect digital detector would have a DQE of __.   show
🗑
As the spatial frequencies increase, the DQE ______   show
🗑
show memory effect  
🗑
show the persistance of the image, that is, charge is still being produced after the radiation beam from the tube has been turned off.  
🗑


   

Review the information in the table. When you are ready to quiz yourself you can hide individual columns or the entire table. Then you can click on the empty cells to reveal the answer. Try to recall what will be displayed before clicking the empty cell.
 
To hide a column, click on the column name.
 
To hide the entire table, click on the "Hide All" button.
 
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
 
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.

 
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
Created by: Zoest35
Popular Radiology sets