Digital Image Processing
Computed Radiography
DR Flat Panel Detectors
Digital Considerations
Throwback Rad Science
100

How many bits are in one byte?

8 bits in 1 byte.

100

In CR systems, what is the image referred to as before and after processing?

Latent= Before

Manifest= After

100

What are the two classes of DR panels?

Indirect and Direct

100

What is an example of a Digital Marker that can be added after an image is captured?

Upright, Supine, Decub, Cross-table, Inspiration, Expiration... R and L can be added, but it is better practice for them to be from the lead markers. 

100

What are the two types of distortion?

Size and Shape

200

What is the 2D/picture element of the matrix?

A Pixel

200

What are the two common CR PSP phosphors?

Barium Flourohalide Bromides 85% (BaFBR:Eu)

Barium Flourohalide Iodides 15% (BaFL:Eu)

200

What do Direct Detectors use as a photoconductor? 

Amorphous Selenium

200

What is an example of a type of Digital Artifact?

Quantum mottle, inadequate exposures, algorithm artifact, histogram analysis error, non-parallel collimation, poor grid alignment.

200

What is additive and subtractive pathology?

Additive= pathology the increases density

Subtractive= pathology that decreases density.

300

What is the 3D/volume element if the matrix?

The Voxel

300

Where is the Latent Image stored in a CR PSP?

In the Europium holes/ F centers

300

What is the photodiode of an Indirect Detector made of?

Amorphous Silicon

300

What is the ASRT's position on cropping?

It should not be performed because it may result in a missed incidental finding. 

300

A digital receptor has a _____ response to radiation exposure.

Linear

400

Smaller pixels= _______ resolution?

Higher

400

What determines pixel bit depth in CR?

The ADC

400

What are the two types of scintillators?

Cesium Iodide (CsI)- *Preferred*

Gadolinium Oxysulfide (Gd2O2S)

400

What causes data drop?

DEL Saturation; Excessive exposure. 

400

How does atomic number affect attenuation?

High atomic number = high attenuation

500

What are the three types of image processing?

Point, Local, and Geometric

500

Name the layers of the CR PSP. 

Protective, Phosphor, Conductor, Support, Light shield, Backing. 

500

Does a high TFT fill factor yield a higher or lower spacial and contrast resolution?

It yields a higher spatial and contrast resolution. 

500

What is the Deviation Index "sweet spot"?

-0.5 to +0.5

-3 to -1 is underexposed

+1 to +3 is overexposed

500

What is spacial resolution?

The sharpness of anatomical structures that are displayed on the IR.

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