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Question | Answer |
---|---|
t or f? To change from film to CR, significant changes must be made to the X-ray generating equipment | False |
T or f? With a CR system there is no danger of routinely overexposing all patients | False |
T or f? A digital image is composed of a series of rows and columns known as a matrix | True |
What digital imaging modality uses a laser to scan the image plate before the radiographic image is acquired by the computer and displayed to a computer monitor? | Computed radiography |
Digital images are stored by a computer as what? | A series of 0s and 1s |
Digital radiography detector that is also used in consumer digital cameras and camcorders. A. Selenium detector B. Charged coupling device C. Computed radiography | B. |
T or F? The thin film transistor (TFT) used with an indirect flat panel detector is the same as the TFT used for a direct detector | True |
T or F? The photostimulable phosphor stores the energy deposited by the X-ray beam in the plate | True |
T or F? Flat panel receptors are classified as scintillator based or non scintillator based | True |
Which of the following is an advantage when viewing a digital image compared to conventional film? A. Wider latitude B. Brightness of monitor is less than a view box C. Monitors need to be replaced | A. |
Random information within a diagnostic image that detracts from the overall images appearance is known as? A. Contrast B. Detail C. Noise D. Density | C. |
A neural histogram compares the image data to ____ or more predefined histograms. A. 2 B. 3 C. 4 D. 5 | A |
How many people can view a digital image on a PACS simultaneously? | Unlimited |
In what year did the ARC and the NEMA form a joint committee to create a standard process for transmitting medical images? | 1982 |
When was DICOM standard 3.0 published ? | 1993 |
Workstations designated as diagnostic workstations typically are used only by: A. Radiographers B. Medical physicists C. Radiologists D. Physicians | C. |
Long term storage of digital images occurs in which type of storage system? | Archive |
A benefit of installing PACS software on computers throughout the medical facility is increased: A. Image detail B. Viewing functionality C. Access D. Image size | C. |
Prefetching generally occurs at what time of the day? A. The start of the work day B. During the lunch hour C. During the night | C |
A computer network limited to a relatively small geographical area is known as: A. LAN B. WAN C. STAN D.GAN | A |
An advantage of LCD monitors over CRT monitors is that LCD monitors: A. Are more durable B. Lower measurable black levels C. Have less screen glare | C |
_______ refers to continuously verying quantity; a ______ system uses only two values that vary discretely through coding. | Analog, digital |
Computer _____ are the software of the computer. | Programs |
To encode is to translate from ordinary characters to computer compatible characters - ______ _______. | Binary digits |
The electronic circuitry that does the actual _______ and the memory that supports this together are called the _______. | Computation, processor |
Main memory is the _______ storage of a computer. | Working |
Output hardware consists of ______ that translate computer information into a form that humans can understand | Devices |
Input hardware converts ________ into a form that the computer can use. | Data |
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 an: | 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? | The image quality is poor |
A graphical representation of exposure values extracted from an image receptor is known as: | Histogram |
Visual cues that an image has been overexposed are not easily seen in digital radiography because of: | Rescaling |
If a PSP plate is processed using the wrong anatomical menu, what could happen? | The El number might display improperly |
All of the following are advantages to digitizing radiographs except: A. It allows radiologists to view images in new ways B. It provides electronic access to digitized images C. Artifacts are removed during the process | C |
The benefits of the needle shape photostimulable phosphor as compared to the powder based PSP is: A. Less light spread B. Greater absorption of radiation for same thickness C. Better resolution D. All the above | D. |
What is the ideal percentage value for MTF? | 100% |
T or F? A pixel is a two dimensional representation of a corresponding tissue volume, known as a voxel | True |
Which digital imaging modality uses a laser to scan the image plate before the radiographic image is acquired by the computer and displayed to a computer monitor? | Computed radiography |
Viewing an image on a computer monitor, the displayed brightness and contrast are controlled by adjusting the: A. Pixel size B. Window level C. Window width D. B and C | D |
Which department(s) use a digital format for imaging? A. MRI B. CT C. nuclear medicine D. All the above | D. |
Eight bits equals ___ byte(s) | 1 |
T or F? To change from film/screen to CR, significant changes must be made to the X-ray generating equipment | False |
T or F? It is impossible to stitch together multiple images on the CR system | False |
T or f? DR requires a plate reader for processing of the image | False |
Which if the following is an advantage when viewing a digital image compared to conventional film? A. Wider latitude B. Brightness of monitor is less than a view box C. Monitors need to be replaced | A |
T or F? Digitally captured images suffer from a toe and shoulder similar to the H&D curve of X-ray film | False |
T or F? Soft copy is the term that refers to the output seen on a display screen | True |
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 |
Which 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 _____. | A red laser beam |
Direct image formation converts X-rays into _______. | Electrons |
Individual components of a digital imaging 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 ____% under exposure and ____% overexposure | 50, 100 |
What is a visual cue that a digital image is underexposed? | Increase image noise |
______ ______ is determined by the percentage of energy that strikes a receptor material that is absorbed by the receptor | Absorption efficiency |
Which of the following is not an advantage of digital imaging? A. Greater contrast range B. Long term storage is easier C. Better resolution D. Post processing capabilities | C. |
In digital imaging, _____ is determined by pixel size. | Spatial resolution |
Which of the following affects the number of shades of gray for a digital image? A. Matrix size B. Field of view C. Bit depth | C. |