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Digital Final Exam
Final Exam from All Digital Modules
Question | Answer |
---|---|
The beam that contains useful or diagnostic information is known as the: | Remnant Beam |
Digital imaging systems have a large dynamic range, which means that they can respond to a wide range of: | Exposures |
In analog imaging, the intensifying screen converts x-rays into: | Light Photons |
In an analog-to-digital converter, the analog input consists of: | Electrons |
What symbols compose the binary language? | 0, 1 |
How many shades of gray does an 8-bit image display? | 256 |
As the pixel size decreases, the recorded detail: | Increases |
Scintillation refers to a material’s ability to give off: | Light |
The acronym PSP stands for photostimulable: | Phosphor |
During processing, image data is released from a PSP receptor after the receptor is struck by: | Red Laser Beam |
Direct image formation converts x-rays into: | Electrons |
Individual components of a digital image are collected in areas of a thin-film transistor known as: | DELs |
Random information within a diagnostic image that detracts from the overall image appearance is known as: | Noise |
CCDs are suitable for low-dose imaging because they: | Respond to low light levels |
DQE is a measure of image: | Quality |
Selecting a lower sampling frequency during image processing results in: | larger pixel size and lower spatial resolution |
For flat-panel detectors, the spatial resolution is determined by the size of the: | DELs |
The Nyquist theorem states that for a given spatial resolution, you must sample the signal at ____ times the desired sampling frequency. | 2 |
A digital receptor can produce an image that appears acceptable on a display monitor, but that was produced between: | 50% Underexposure and 100% Overexposure |
Which of the following is a visual cue that a digital image is underexposed? | Increase in image noise |
Receptor blur is the result of: | Imaging Equipment |
When a digital fluoroscopy unit’s magnification button is used, the resulting magnification is due to a decrease in the size of the: | Input Phosphor |
Scanning the bar code on a PSP plate is extremely important because it links the image data with the correct: | Patient |
Which device allows for an increased scanning precision compared with a mechanical arm? | Rotating Mirror |
In a PSP plate reader, the light guide collects the light and directs it into a: | Photomultiplier Tube |
PSP plates are erased after processing by exposing the plate to: | High intensity light |
When using a flat-panel detector, the technologist does not touch the: | Image Detector |
In a flat-panel imaging system, electrons are converted into digital values by a(n): | ADC |
What do both a charge-coupled device and a complementary metal oxide semiconductor need to change x-rays into light? | A Scintillator |
What happens when a PSP plate reader is unable to identify the collimated borders of the image? | Poor Image Quality |
A graphical representation of exposure values extracted from an image receptor is known as a: | Histogram |
Type 3 a priori analysis is unique because it takes into account which patient characteristic? | Prosthesis |
Neural analysis compares exposure data from the receptor with: | Values in a predefined data set |
Visual cues that an image has been overexposed are not easily seen in digital radiography because of: | Rescaling |
The acronym EI is a vendor-neutral term that stands for exposure: | Indicator |
All of the following are examples of EIs except: a) S number b) DQE c) lgM d) REX | DQE |
The addition of a metal prosthesis into the image data set affects: | Image Brightness, Contrast, and EI |
If a PSP plate is processed using the wrong anatomical menu, what could happen? | the EI number might display improperly. |
Optimal EI ranges for each anatomical part should be set by the: | Radiologist |
Which of the following is an EI used in flat-panel radiography? A)EXI, B)S number, C) DQE, D)lgM | EXI |
A DAP meter measures patient dose as the x-rays: | Enters the patient's skin |
All of the following are advantages to digitizing radiographs except: a)Allows radiologists to view images in a new way, b)Provides electronic access to images, c)image can be uploaded to PACS, d)Artifacts removed during the process | Artifacts removed during the process |
In CRT display technology, an electron gun fires electrons at a(n): | Fluorescent Screen |
An advantage of LCD monitors over CRT monitors is that LCD monitors: | Have less screen glare |
An LCD monitor’s resolution is determined by: | Pixel Pitch |
Most LCD monitors have an aspect ratio of: | 16:09 |
Which of the following increases as the matrix size of a display monitor increases? | Spatial resolution |
Pixel pitch describes: | How close the pixels are to each other |
To accurately display the gray scale in a radiograph, the display monitor must be able to demonstrate at least how many distinct shades of gray? | 256 |
The difference between the maximum and minimum luminance of a display system is called: | Contrast Resolution |
Current ACR standards specify that gray-scale monitors used for interpreting radiographs provide a minimum of how many cd/m2? | 171 cd/m2 |
How many images/second does it take CRT monitors to refresh? | 60 - 120 |
The delayed light emission that occurs in a CRT monitor after the screen refreshes is called: | Persistence |
The brightness of a display monitor is referred to as: | Luminance |
Modifying demographic and image data on a workstation also alters the: | Permanent Patient Record |
If an image is acquired with the orientation of the image receptor upside down, what modality workstation tool can be used to orient the image the correct way? | Rotate |
Placing image information on an image after the examination is complete is called image: | Annotation |
When an image is obtained on several imaging plates that need to be combined later into one image, the process is referred to as: | Stitching |
Cassettes that are specially designed for scoliosis exams contain how many PSP plates? | 2 |
Using a workstation to cover the unexposed area of an image with a black border is called: | Shuttering |
Window and leveling on a workstation changes the digital image’s: | Brightness and contrast |
Which of the following would lead to decreased density on an analog (film-based) image? | Low development temperature |
Radiographic blur can be caused by: | Patient Motion and Geometric Factors |
Excessive radiation is defined as using more than ________ times the level of radiation needed to produce a diagnostic quality image. | 3 to 4 |
What error is caused by the computer’s inability to identify the edges of collimation? | Exposure Field Recognition Error |
Improper alignment of a radiographic grid during digital imaging can lead to improper: | Contrast |
Scatter radiation is especially difficult to interpret during histogram analysis when it occurs: | Outside the collimated field |
Inappropriate brightness on a digital image can be caused by: | Poor collimation, Incorrect menu selection, Poor Positioning |
When the exposure absorbed by the image receptor surpasses the level at which the image receptor can respond, what is said to occur? | Saturation |
What is the most common cause of image blur in digital imaging? | The patient |
Shape distortion can be caused by: | Angular relationship of tube, part and Image receptor |
Primary cause of quantum noise is: | Insufficient signal strength |
DAP is a measurement of: | Exposure |
A lead apron in the exposure field may cause an exposure indicator miscalculation because the image data could be misrecognized as: | Gross underexposure |
To reduce errors from collimation, the current recommendation is to: | Record one image per image receptor |
Most digital artifacts appear: | White |
Most artifacts that appear when using cassette-based digital imaging are caused by: | Dust and dirt |
Most artifacts that appear when using cassette-less systems are caused by: | DELs |
Digital artifacts that are caused by processing: | Appear along the entire axis of the image and on every imaging plate. |
Artifacts caused by a dirty light guide appear: | White and linear |
An artifact that presents as a wavy appearance in a localized area of an image is due to: | Laser and/or plate disruption |
In the abscense of a PACS, digital images can be: | Laser printed |
How many people can view a digital image on a PACS simultaneously? | More than 10 |
The standard process for transmitting medical images and their associated information is known by the acronym: | DICOM |
A modality workstation provides information that can be used by a limited number of users is known as a: | SCU |
A radiology information system (RIS) can do which of the following? | Collect and display orders |
The software standards used for the exchange of text-based electronic information in health care are known as: | HL7 |
Workstations designated as "diagnostic workstations" typically are used only by: | Radiologists |
Long-term storage of digital images occurs in which type of storage system? | Archive |
A typical 5-view lumbar spine series requires storage space up to: | 25MB |
Which of the following is an example of an image acquisition modality workstation? | CT Scanner workstation |
A PACS uses RAID as its main: | Storage Device |
Prefetching generally occurs at what time of day? | During the night |
The greatest benefit of installing PACS software on existing computers throughout the medical facility is increased: | Access |
A typical PACS platform receives images from: | CT, MR, Digital Fluoroscopy |
A computer network limited to a relatively small geographic area is known as a: | LAN |
Every computer on a network has a unique indentifier known as a(n): | IP Address |
What device connects 2 or more networks? | Router |
A firewall controls traffic between a single computer and a network in an environment with no: | Security |
The major challenge with burning images to a disc to share the image information with another facility is: | Viewing images on the receiving end |
The term "night hawking" describes a radiologist contractor who: | Interprets images off-site |