Let's get PHYSICal
A Bistable display is composed of this many shades.
What is two?
Gray scale imaging was initially made possible because of this, it first stores information and then later displays it.
What is a Scan Converter?
The 2 elements of a digital scan converter.
What is a Pixel and a Bit?
This uses computer technology to convert images into numbers. (a process called digitizing)
What is Digital Scan Converter?
This was the first type of Scan Converter.
What is analog scan converter?
The two user controls on video monitors that can alter the characteristics of a displayed image. (for extra points: what do they determine?)
What are Contrast and Brightness?
Contrast - range of brilliance
Brightness - brilliance
The smallest building block of a digital picture.
What is pixel?
The number of shades of gray that can be represented by 7 bits?
What is 128?
The amount of pixels per inch and the size of the pixels have this type of relationship.
What is inversely related?
The smallest amount of computer memory.
What is Bit
Is the set of rules, or protocols, that allows imagining systems to share information on a network.
What is DICOM? for extra points: what does DICOM stand for?
During this type of magnification, the system displays only the original data that pertains to the ROI and the ROI is not rescanned.
What is read magnification?
The amount of bits needed to store 14 shades of gray.
What is 4 bits?
What improves contrast resolution and contains more shades of gray?
More bits per pixel (think of the equation)
The two forms of magnification.
What is Read Magnification and Write Magnification.
The list of things we can manipulate in an image after storage, aka postprocessing.
Any changes after freeze frame.
3-D rendering
Contrast Variation
Black and White Inversion
Read Magnification
During this type of magnification, there is an increase in the number of pixels in the ROI which improves spatial resolution.
What is Write Magnification?
The 5 advantages of digital scan converters.
What are:
1.Uniformity
2. Stability
3. Durability
4. Speed
5. Accuracy
The four limitations of Analog Scan Converters.
What is:
1.Image Fade
2.Image Flicker
3.Instability
4.Deterioration
Coded excitation occurs in the pulser and provides 5 advantages, list them.
Deeper Penetration
Improved Spatial Compounding
Improved Axial Resolution
Improved Contrast Resolution
Higher Signal to Noise Ratio
The list of things that we can manipulate in an image before storage, aka preprocessing.
Log Compression
Edge Enhancement
Fill-in Interpolation
TGCs
Spatial Compounding
Write Magnification
Persistence
Spatial compounding reduces speckle and shadowing artifacts, but has these limitations.
Reduced Frame Rate and Reduced Temporal Resolution.
Name at least 2 advantages of PACS.
Instant access to archived images
No deterioration/degradation of data
Ability to electronically transmit images and reports to remote locations
(extra points: what does PACS stand for?)
This is a process known for superimposing the current frame on previous frames to create a smoother image.
What is Persistence?
In temporal compounding (aka persistence or temporal averaging) all of the images used are from the same view. But in spatial compounding they are from different views or angles.