Rad 102 ch 20 study guide

DR receptors referred to as _____ panel detectors

Measure of how sensitive and accurate incoming data is converted to output viewing is know as

Windowing is for ____ and ______

Pixel has a “special” location refers to

The smaller the pixels in a matrix the clearer the image

Higher DQE means higher dose

LUT’s do not vary between exams

Large matrix has larger pixels

Histograms don’t automatically rescale the values if interest

Exposure index is calculated using histogram values and pixel values of interest

Indirect conversion uses what

Operations that are performed between the receipt of input image from the IR and the output image on the monitor

Number of cycles per unit length (frequency) refers to

Point processing operations involves the creation and analysis of

Spatial resolution increases if matrix size and pixel size increase

What are the qualifications of Noise

Determined the number of assigned gray shades to pixel value

CR/DR receptors have bad LCR

LUT values are assigned to data points (pixels) in the histogram

Bit strings connected as _____

Systems can suppress noise to a certain point

Pixel pitch is dependent on

The LUT contains stored data to substitute new values for each pixel during processing

Quantification is each sampled piece of analog data computed and given a discreet analog value

What is the two symbol alphabet for binary machine language

The mathematical algorithm applied to change an image from spatial location to spatial frequency is

The smaller the field of view the less magnified the anatomy is

Electrical signals move from receptors in an _______ format

2^12 bit depth yields how many gray shades

What are the two domains digital images are represented in

Pixel bit depth is controlled by

Point processing operations involve the application of the

Greater bit depth yields less range of gray shades

Greater bit depth increases size of data set and volume of date for image processing

High S/N means lots of noise

ADC involves two distinct steps _____ & ______

Low pass filtering is referred to as

High S/N has a direct relationship to contrast

Digital data consists of byte values

Deals with the ability to visualize subtle energy differences, particularly in soft tissues

Low S/N has an inverse relationship to contrast

Change input value to improve diagnostic quality of output image refers to

Matrix is made up of ____ and _____

DR systems have a DQE between 30 and 70 percent

The physical distance between pixels is

The proper LUT will provide proper grayscale, regardless of variations to mAs and kVp

If pathologies are difficult to visualize you would use a LUT

The overall dimension of the image matrix is called the

Operations in which mathematical calculations are applied to only a small group of pixels

Geometric processing operations allow ____ and ____

Computed radiography has what kind of imaging plates

Calculations applied to small group of pixels is referred to as

Spatial resolution translates to image _____

Gray scale bit depth ranges from 8 to 32 bits

Increased noise decreases image contrast

A graphical display of the pixel values that make up the image is

Pixel is the ____ element

If matrix size increases then pixel size

Operations used to change the position or orientation of the pixels in the image

Histograms determine values of interest and median number (exposure indicator number)

LUT’s vary between manufacturers

Lower S/N numbers are always better

What are the two types of digital imaging systems

Sub optimum exposure values can be compensated for with LUT’s

What are the types of digital radiography

Each body part has a reference histogram

Spatial frequency more commonly used by physicians and engineers

Noise is measured in a signal to noise ratio (SNR)

Shape of histograms correspond to specific anatomy

_____ bits = ______ byte

Provides information about exposure to IR

Spatial location used more by physicians and radiographers

All equipment and all manufactures use different computer language

High pass filtering is also referred to as edge enhancement or sharpness

Pixels are measured from edge to center

Insufficient quantity of photons is which type of noise

10 bit = how many gray shades

A DQE OF 1 = 100 percent or no loss of information

There is no universal system for exposure index

Unsharp masking is referred to as

Image file size is affected by

Voxel is the ____ element

LUT’s cannot enhance pathologies

Different manufacturers use the same systems

Computer ____ and ______ expressed in total bytes

Analog information must be converted to digital

Sampling is analog voltage measured at “chosen” sampling frequency on waveform

LUT’s produce a contrast-look according to reference contrast scale for exam view

How is analog information converted to digital language

Exposure index does not vary between vendors

Makes adjustments to image contrast

Histograms are generated before exposure is made

Pixel pitch is inversely related to spatial resolution

Digital image formation requires ______ machine language