radi 172 final

Three main types of acceptance testing include all of the following

visual check, phantom image test, image erasure test

Daily test regarding quality assurance includes

visual inspection, plate reader inspection, laser printer QC, monitor QC

Monhtly QA test include all of the following

PSP plate erasure, phantom image test, monitor calibration

Excessive dark noise improves the digital image. True or False

False

Failure to demonstrate a uniformly bright image means that there may be a problem with the PSP plate or the reader(processor). True or False

True

With Image Brightness Uniformity, a ______ % variation in pixel value is allowed

10

Regarding digital imaging QA, this test assesses pixel values.

linearity and slope

With this test, a radiograph is processed through the PSP reader to determine if its edges, of the displayed image, are straight and continuous.

laser beam function

The high contrast resolution test uses a grid that measures line pairs per millimeter to assess the high contrast resolution capability of PSP systems. True or False

true

If a PSP imaging plate is not thoroughly erased, noise will be added to the next image. True or False

true

The wire mesh test is utilized to access _______________

distortion

The daily monitor test is performed using which of the following test tool devices?

SMPTE and TG18QC test pattern

Part of the daily plate maintenance and cassette inspection involves checking the PSP imaging plate for cracked or broken hinges. True or False

True

PSP imaging plates should be erased at least every 48 hours if they have not been in use. True or False

True

If you come across a cracked or broken PSP imaging plate, just throw it in the garbage. It doesn't matter how you dispose of it! True or False

False

This refers to the number of pixels in a matrix and the size of the display screen

spatial resolution

When viewed in a landscape format, LCD moitors typically have an aspect ratio of 4:3. True or False

False

The gaps between pixels where no image information is displayed is called:

dead space

A bit depth of 1 equals a monochrome color display. True or False

True

PACS stands for picture archiving and communication systems. True or False

True

This imaging standard and interface format ensures the adaptability between different imaging systems.

DICOM

In 1985, this very first standards for PACS were established.True or False

true

RAID is used for long-term storage. True or False.

False

__________ sets the standards for the transmission of text-based patient information.

HL7

The jukebox is the largest of the long-term storage devices for digital images. True or False

True

This person is responsible for assuring that a PACS oprerates at its maximum functionality and efficiency.

PACS administrator

An extension of PACS, this is the process of remote transmission and viewing digital images.

teleradiology

In 1982, the ACR and NEMA formed a joint committee and created standard processes for transmitting medical images and their associated information. True or false

true

HIPPA/Patient Confidentiality is no longer a concern with digital imaging. true or false

false

The probability that an x-ray will interact with an image receptor depends on

thickness of capture layer and atomic composition

Digital systems can be operated at a wide range of exposures, therefore making the term "speed" an inappropriate descriptor. True or False

True

This is a measure of x-ray absorption effceincy

DQE

Characteristics of PSP's include the following

phosphor types, conversion efficiency, system speed class, DQE

With digital imaging systems, contrast is now unrelated to dose unlike analog film-screen systems. True or False

True

You can not and should not collimate with digital imaging systems because it could result in a histogram error. True or False

False

A partial loss of a row of DEL's can be fixed easily because all you have to do is replace the individual DEL or row of DEL's. True or False

False

Digital imaging systems are more sensitive to scatter and background radiation than analog film-screen systems. True or False

True

With digital imaging systems, your kVp may be ______________ kVp higher than with analog film-screen systems.

5-15

__________________ is the rate at which x-ray energy is transformed into light in an intensifying screen.

conversion efficiency

With digital imaging systems, an additional 0.1-0.2 mm of copper filtration is recommended to reduce patient dose. True or False

True

Rescaling forces a radiographer to look elsewhere for signs that a proper exposure was used to produce an image. True or False

True

DQE is highest for _________ systems and lowest for __________ systems.

DR, analog-film screen

____________ refers to the tendency, with digital radiography, to gradually increase patient dose over time.

dose creep

You do not need to use a grid with digital imaging systems. True or False

False

Digital imaging blur is caused by motion and changes in geometric factors. True or False

True

Needle crystals result in more light divergence when stimulated compared to turbid phosphor material. True or False

False

Digital imaging is mAs driven. True or False

False

Suggested ways aimed at controlling patient exposure with digital imaging systems include

additional filtration, higher kvp, interfacing with AEC, maintain ALARA

Common image capture elements utilized with digital image receptors include all of the following

BaFBr, Csl, a-Se

With the advent of digital imaging systems, it has become a lot harder for patient dose to be monitored. True or False

False

look at images and causes for problems!

ok

This may result in histogram analysis errors and rescaling errors.

inappropriate collimation and beam alignment

Prior to image creation, the exposure values extracted from the PSP plates are subject to a process know as:

quantization

Excessive processing could result in an inaccurate dictation/diagnosis due to inappropriate default processing. True or False

True

Quantization may sometimes be referred to as

sampling frequency

With Priori Historam Analysis, the standardized set of data comes from two or more pre-defined histograms. True or False

False

The predetermined values used to create the digital image are known as:

values of interest

PSP's respond to an exposure as low as ____________ micro-roentgens

60

Scatter radiation is not part of the useful beam. True or False

True

Ways at reducing scatter radiation include which of the following:

beam limiting, optimal exposure, grid use, utilizing compression bands

Is a grid a beam limiting device?

no

With Neural Histogram Analysis, a digital image is created after extracted data is matched to exams derived from experiments of like subjects under ideal conditions. True or False

False

Spatial resolution is one of the principal factors affecting the amount of scatter radiation produced. True or False

False

Changes in kVp will not greatly affect radiographic contrast as it did with film-screen combinations. True or False

True

To help avoid the Moire Effect a technologists should:

make sure grid line isn’t running the same way, use a high-frequency grid, use a grid with 103-178 lpi

Automatic rescaling can also be referred to as auto ranging, rescaling, scaling, and normalization. True or False

True

If you see gray areas outside the exposure field borders, a PSP exposure field recognition error might have occured. True or False

True

____________ describes the concept of density as it is displayed on a soft-copy monitor for digital image viewing.

brightness

Image contrast describes the difference between adjacent densities. True or False

True

Excessive edge enhancement may cause this type of artifact:

Halo

Digital filtering transforms images into their corresponding _____________.

frequencies

Low-pass filtering may also be classified as smoothing and/or noise suppression. True or False

True

Smoothing greatly improves edge visibility. True or False

False

Too much equalilzation can result in a poor image. True or False

True

High-pass filtering either amplifies or deletes all but the low frequencies. True or False

False

Scatter Radiation is produced during _____________ interaction.

compton

High-pass filtering may also be referred to as edge enhancement. True or False

True

Equalization is a software function designed to even out the noise displayed in a digital image. True or False

False

_____________ graphically represent a collection of exposure values extracted from the digital image receptor.

histograms

This term describes excessive equalization caused by a metal prosthesis.

metal mottle

An important step in the analysis of image data is recognizing exposure field borders. True or False

True

______ replaces the visual cues of density and contrast used in analog imaging systems.

exposure indicators

This is defined as the degree of geometric sharpness or accuracy of structural lines recorded in the image.

detail, definition, spatial resolution

How many shades of gray are possible with a 6 bit system?

64

Cassette-based digital radiography systems uses a _________________ inside an imaging plate.

photostimulable storage phosphor

Digital images are made of discrete picture elements, or _______________, arranged in a matrix.

pixels

With "direct digital" radiography, a cassette is not needed. true or false

true

Direct Acquisition systems utilize this as the detector.

amorphous selenium

With cassette-based digital systems, a thin film transistor (TFT) and individual detector elements collect the image. true or false

false

In digital radiography, this type of system uses a two-part process that involves both a scintillator and a photodetector.

indirect acquisition

These collect the electrons given off by Amorphous Selenium or Amorphous Silicon.

DELs

The two types of plate scanning mechancis found with cassette-based digital imaging include:

line scan and flying spot scan

What happens to the patient dose if I have a high DQE.

decreased

As DQE decreases, the noise in a digital image is reduced. true or false

true

An underexposure greater than 50% result results in a loss of image contrast. true or false

false

What is the function of a scintillator?

converts incoming xray photons to light

___________________ is the range of under or overexposure that can occur in producing an acceptable image and does not violate ALARA.

exposure latitude

In digital imaging, exposure level and spatial resolution are closely associated. true or false

false

With Carestream digital imaging systems, doubling the exposure increases the EI by 300. true or false

true

With digital imaging, the latent image loses about _________ % of its energy in approximately 8 hours.

25