____ is accomplished by using a specialized Image Receptor that can produce a computerized Radiographic Image

___ is formed in the PSP when the exit x-ray intensities are absorbed by the Phosphor and the Europium Atoms become ionized by the Photoelectric Effect

___ is the emission of light when stimulated by Radiation

___ phenomena that emits visible light when stimulated by a high-initensity laser beam

___ is a layer composed of Barium Fluorohalide Crystals doped with Europium

CR Latent Image is acquired in the ___ of the Imaging Plate.

___ have a self scanning readout mechanism that employs an array of x-ray detectors that receive the exit radiation and convert the varying x-ray intensities into proportional electronic signals for digitization.

CR require 3 steps for Imaging Acquisitions and results in a longer delay between Image Capture and Image Readout

DR Images take awhile to process after exposure.

Digital Radiography Receptors are stronger but more expensive than Computed Radiography Receptors

___ is a solid-state IR employing a large-area active matrix array of electronic components

Which layer of Flat-Panel Detectors houses the Thin-Film-Transister (TFT) Array

___ contains an x-ray sensitive area representing each Pixel in the Image Matrix

What limits Spatial Resolution for Flat-Panel Detector IRs?

____ uses a Scintillator to convert Exit Radiation into visible light

Scintillator is made up of Cesium Iodide (CsI) or Gladolinium Oxysulfide (Gd202S)

__ will produce light following the absorption of the x-rays.

Scintillator will produce light following the absorption of x-rays and is then converted to Electrical chargers by ___

Where are eletrical charges temporarily stored, in the TFT array of Indirect Conversion Detectors, before being digitized?

Structured Scintillator Phosphors are in the form of needles or columns and ___ the spread of visible light and yields images with ___ Spatial Resolution

(Choose 2) Indirect Conversion Detectors convert x-ray intensities to ___ then to ___

Converts Exit Radiation to Electrical charges.

Converts Exit Radiation to Visible Light then to Electrical Charges

Constructed with layers in order to receive x-ray photons and convert them to Electrical Charges for storage and readout

___ uses Amorphous Selenium (a-SE) Detectors to convert the Exit Radiation to electrical charges

What is applied across the Selenium Layer to limit Lateral Diffusion of electrons as they migrate toward the Thin-Film Transistor Array?

Applying an electric field to Direct Conversion Detector maintains excellent spatial resolution

___ a digital composite of the varying x-ray intensities exiting the patient

___ are patterned in the computer to form the Image Matrix.

Each Pixel has a brightness level to represent ___ of the volume of tissue being imaged.

Once varying x-ray intensities, in Direct Conversion Detectors, are converted to numeric data, the digital image can be electronically be: (choose 4)

Advantages of Digital Imaging: (Choose 3)

Combination of rows and columns of small squares called pixels

Smallest Component of the Matrix

Each Pixel is recorded as multiple numerical values to represent brightness level on a display monitor.

Pixels representing highly attenuating tissues means ___

Pixels representing highly attenuating tissues means ___

Pixels representing highly attenuating tissues means ___

Pixels representing tissue of Low Attenuation means ____.

Pixels representing tissue of Low Attenuation means ____.

Pixels representing tissue of Low Attenuation means ____.

If Field of View is increased for a Fixed Matrix Size

If Matrix Size is increased for a Fixed FOV:

Pixel Size is inversely related to FOV and directly related to Matrix Size

Increasing FOV for the SAME Matrix Size: (Choose 2)

Increasing the Matrix Size (Same FOV): (Choose 2)

Number of bits that determines the precision with which the Exit Radiation is recorded and controls the exact Pixel Brightness that can be displayed

Pixel Bit Depth is determined by an Analog to Digital Converter (ADC)

Larger the Bit Depth > Lower Shades of Gray

___ is limited to the size of the Pixel

___ is defined by the unit of line pairs per millimeter (lp/mm)

Smaller Objects have: (Choose 2)

Larger Objects have: (Choose 2)

Measurement of the Imaging System's ability to display contrast of Anatomic Objects varying in size

MTF of 0 shows __ in brightness levels. MTF of 1.0 shows __ in brightness levels

Determines how often the Analog Signal is reproduced in its discrete digitized form

Difference between the Sampling Points

Each pixel is assigned to a numerical value during this process

To digitize a Digital Signal from the Photomultiplier Tube, it first must be sampled.

Increasing Sampling Frequency creates a smaller Sampling Pitch

Increasing the Sampling Frequency: (Choose 3)

Manufacturers use Fixed Sampling Frequencies to maintain ___ Spatial Resolution

Manufacturers use Varying Sampling Frequency to maintain ___ Matrix Size

If a Matrix Size is fixed, changing the size of the IP would affect the Spatial Resolution.

For a Fixed Matrix Size a CR System, using a smaller IP for a given FOV would:

Increasing the size of the IP for a given FOV would:

What determines Spatial Resolution? (Choose 2)

What determines the system's ability to display a range of shades of gray to represent Anatomic Tissues?

The ability of a detector to accurately capture the range of photon intensities that exit the patient.

CR Imaging Receptors have a much higher Dynamic Range.

An advantage of Digital IR is even with a small degree of underexposure and overexposure would still result in an acceptable Image Quality.

Even if Optimal Exposure Techniques are not used, what can help during the processing step can produce images with the appropriate brightness levels

Lower than necessary x-ray exposures can be detected and processed > Image Quality suffers because there is insufficient exposure and results in ___.

Computer can process the data resulting from an IR exposed to higher-than-necessary-radiation and produce a quality that results in a(an)___.

Digital IR have a Wide Dynamic Range and can accurately capture a narrow range of x-ray intensities exiting the pt

Measurement of the efficiency of an Image Receptor in converting x-ray exposure it receives to a Quality Radiographic Image.

A higher DQE means:

Method of describing the strength of the Radiation Exposure compared with the amount of noise to apparent in the Digital Image.

Because the Photon Intensities are converted to an Electronic Signal that is Digitized by the ADC, what term refers to the strength or amount of Radiation Exposure captured by the IR to create an Image?

____ the SNR improves the quality of the Digital Image

____ the SNR means ____ in Noise compared to the Strength of the Signal. (Choose 2)

Occurs when there are too few x-ray photons captured by the IR to create a Latent Image.

Method of describing the Contrast Resolution compared with the amount of Noise apparent in a Digital Image

Brightness difference sin the Digital Image are a result of varying Exit Radiation Intensities from the ___ of the x-ray beam.

A system with ___ means that Anatomic Tissues that attenuate the x-ray beam with Low Subject Contrast can be better visualized.

If the image has increased Noise, the _______ will not be well visualized

___ CNR will increase the visibility of Anatomic Tissues

An Imaging Processing Technique commonly used to identify the edges of an image and assess the Raw Data prior to Image Display.

Histogram Analysis is used for maintaining a consistent Image Brightness despite overexposure and underexposure of the IR.

Graph of a Histogram represents the ___ VS the ____ (Choose 2)

In Histogram Analysis, a computer analyzes the Histogram using processing algorithms and compares it with ______ specific t the Anatomic Part being imaged.

If at least 3 edges are not identified, during an exposure, all data including raw exposure or scatter outside the field, may be included in the histogram, resulting in ____

Provides a numerical value indicating the level of Radiation Exposure to the Digital IR.

S Value of an Exposure Indicator is ____ related to the exposure.

Exposure Index is ____ related to the exposure.

Value that reflects the difference between the desired and the actual exposure to the IR.

DI of 0 indicates:

DI of greater than 0 indicates:

DI of less than 0 indicates:

Digital Artifacts usually occurs ___ Image Data Extraction ___ to the ADC or ____ the ADC Process and subsequent Signal Processing performed by the computer up to the point of Image Display.

IP Stains, Particulates, Scratches, Cracks, and Fogging are examples of ____.

On CR Systems, what causes issues related with the Laser Optics, Transport Mechanisms, Light Guide, and Laser Sampling and Stationary Grid Frequencies?

What refers to the display of the Digital Image at a Computer Workstation as opposed to viewing Images on Film or another physical Medium?

The quality of a Digital Image is not affected by important features of the Display Monitor.

Luminance, Resolution, and Viewing Conditions (such as Ambient Lighting and Monitor Placement) are important factors in Computed Radiography.

Which type of Display Monitor creates an image by Accelerating and Focusing electrons to strike the Faceplate of a Fluorescent Screen?

A Display Monitor where an Image is scanned on the screen in lines. The number of lines affects the quality of the Displayed Image.

A display monitor that recommends that it can scan at least 525 lines per 1/30th of a second.

A display monitor that passes light through Crystals to display the Image on the Faceplate.

A display monitor that uses: Source for the electrical signals, light waveforms, and polarizing filters.

What happens if you use a Display Monitor for viewing a Digital Image that cannot display a Matrix of that size (too few display pixels)?

Varying brightness levels emitted from the Monitor affects the quality of the Display Image.

Luminance is expressed in Units of Candela per Square Meter

Primary Monitors should be in the range of ____ Candela Per Square Meter

What determines Contrast Resolution of a Digital Image?

A Digital Imaging System capable of displaying 16,384 shades of gray (14 bit) requires a Monitor capable of displaying a Large Grayscale Range.

___ refers to a computer software available to the Radiographer and Radiologist that allow Manual Manipulation of the Displayed Image.

___ is when an Image is processed, regions viewed on the image can be altered further.

Another name for Shuttering

Altering the numerical data (brightness level displayed on the computer) to alter and better visualize the range of the recorded anatomic structures describes what?

What sets the midpoint of the Range of Brightness visible in the image?

as Window Level increases, Image Brightness ____.

How would you decrease Image Brightness using the numerical data displayed on the computer monitor in post processing?

Full range of Digital Image Brightness Levels:

High Pixel Value of 1078 > Volume of Tissue attenuates ___ x-ray photons and is displayed as ___ Brightness Level

Low Pixel Value of 350 > Volume of Tissue attenuates ___ x-ray photons and is displayed as ___ Brightness Level

Number of different Shades of Gray that can be stored and displayed by a Computer System

Ability of the Imaging System to distinguish between objects that exhibits similar Densities because they Attenuate the x-ray beam similarly.

A control that adjusts the Radiographic Contrast

Contrast resolution is determined by ____. (Choose 2)

Decreasing the Contrast Resolution, when Optimally Windowed, increases the visibility of very subtle Anatomic Features.

Wide Window Width: (Choose 2)

Narrow Window Width: (Choose 2)

Technique that can remove superimposed structures so that the anatomic area of interest become more visible

Postprocessing technique that alters the Pixel Values to increase Image Contrast.

Improves visibility of small,high contrast structures; but increases noise

Reverses the grayscale from the Original Radiograph

suppresses Image Noise; Spatial Resolution degrades

Underexposed areas (light areas) are made Darker and Overexposed areas (Dark Areas) are made lighter