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Radiography II - Bushong Chapter 21

Terms in this set (46)

What are the 3 Digital Radiographic Artifacts?
1. Image receptor artifacts
2. Software artifacts
3. Object artifacts
What type of artifact is dead pixels, rows, and columns?
They also show up during failure of electronic preprocessing which causes uninterpretable images.
A. Image Receptor Artifacts
B. Software Artifacts
C. Object Artifacts
B. Software Artifacts
What type of artifact does backscatter radiation contribute to?
Patient positioning error, collimation and histogram selection can also potentially cause this problem.
A. Image Receptor Artifacts
B. Software Artifacts
C. Object Artifacts
C. Object Artifacts
What type of artifact are scratches and/or dusts?
Can also be seen when roughly handled which causes ghost images.
Can also have residual glue on imaging plates and/or pixel malfunction.
A. Image Receptor Artifacts
B. Software Artifacts
C. Object Artifacts
A. Image Receptor Artifacts
What are the two types of data compression techniques?
Lossless compression & Lossy compression
Data compression technique can cause what type of artifact?
A. Ghost image artifact
B. Software artifacts
C. Irregular patterns
D. Compression artifacts
D. Compression artifacts
What type of artifact is caused by irradiation of digital radiographic image receptor by the raw x-ray beam which may show variations in density (brightness) over the image?
A. Ghost Image
B. Dead rows or columns of pixels
C. Irregular patterns
D. Interpolation
C. Irregular patterns
What is a software correction that is performed to equalize the response of each pixel to a uniform x-ray beam?
A. Lossless compression
B. Flatfielding
C. Lossy compression
B Flatfielding
What type of compression can be reconstructed to be exactly the as the original image?
A. Lossless compression
B. Lossy compression
A. Lossless compression
What can be done to a cassette to reduce the effect of backscatter?
Shield the back of the cassette
Lossless compression reduces file size ___% to ___% of the original file size.
10% to 50%
(10:1, 2:1)
Backscatter radiation can contribute to object artifacts.
True or False
True
If a CR IP has not been used for 24 hours and is not erase before use, what type of artifact will it cause?
Incomplete erasure of a previous image on a CR imaging plate can also lead to this problem.
Ghost Image
What is the mathematical process of assigning a digital value to a dead pixel based on recorded values of the adjacent pixels?
A. Flatfielding
B. Lossless compression
C. Interpolation
D. Lossy compression
Interpolation
Lossless compression up to ____ is generally considered acceptable and helpful in digital radiographic image management.
A. 10:1
B. 2:1
C: 3:1
D. 4:1
3:1
In Lossy compression the compression factor of _____ or more is used.
A. 10:1
B. 100:1
C. 50:1
D. 6:1
100:1
What type of data does CAD (computer aided detection) systems require?
A. Compressed data
B. Uncompressed data
Uncompressed data
CAD systems could miss lesions if data is used due to compression artifacts.
Compressed
Which compression is used when fine detail is not required such as video recording that are to be played on a standard domestic television.
A. Lossless compression
B. Lossy compression
B. Lossy compression
What does CAD stand for?
A. Computer aided deletion
B. Computer aided detection
C. Chemical aided deletion
B. Computer aided detection
Lossy compression is acceptable for archiving mammography images?
True or False.
False
A graph of frequency of occurrence versus digital value intervals is called what?
Histogram
Grids should be high frequency, and the grid lines should run (perpendicular or parallel) to the plate reader's laser scan lines.
Perpendicular
Proper collimation and centering prevent histogram errors that can lead to artifacts.
True or False.
True
Backscatter radiation cannot cause a phantom image.
True or False.
False
What type of artifact is caused by residue from adhesive tape?
A. Imaging Receptor Artifacts
B. Plate Reader Artifacts
C. Image Processing Artifacts
D. Printer Artifacts
A. Image Receptor Artifacts
Object artifacts can arise from the technologist's errors in patient positioning, x-ray beam colllimation, and histogram selection.
True or False
True
Does collimation reduce patient dose?
Yes or No.
Yes
Proper collimation does not improve image contrast.
True or False.
False
What is it called when the image field must be oriented with the size and dimension of the IP to avoid image artifacts?
A. Alignment
B. Partitioning
C. Dividing
D. Double an image
A. Alignment
What type of artifact is caused by cracks in the imaging plate that appear as areas of lucency on the image?
A. Imaging Receptor Artifacts
B. Plate Reader Artifacts
C. Image Processing Artifacts
D. Printer Artifacts
A. Image Receptor Artifacts
What type of artifact is caused by Hair cling to the IP due to static?
A. Imaging Receptor Artifacts
B. Plate Reader Artifacts
C. Image Processing Artifacts
D. Printer Artifacts
A. Image Receptor Artifacts
What is it called that allows two or more images to be projected on a single IP?
A. Alignment
B. Partitioning
C. Dividing
D. Double an image
B. Partitioning
What type of artifact is caused by dark line caused by backscatter?
A. Imaging Receptor Artifacts
B. Plate Reader Artifacts
C. Image Processing Artifacts
D. Printer Artifacts
A. Image Receptor Artifacts
What type of artifact is caused by the intermittent appearance of extraneous line patterns?
A. Imaging Plate Artifacts
B. Plate Reader Artifacts
C. Image Processing Artifacts
D. Printer Artifacts
B. Plate Reader Artifacts
What type of artifact is caused by fine white lines that may appear on the image because of debris on the mirror in the laser printer?
A. Imaging Plate Artifacts
B. Plate Reader Artifacts
C. Image Processing Artifacts
D. Printer Artifacts
D. Printer Artifacts
What type of artifact is caused by horizontal white lines that may be caused by dirt on the light guide in the plate reader?
A. Imaging Plate Artifacts
B. Plate Reader Artifacts
C. Image Processing Artifacts
D. Printer Artifacts
B. Plate Reader Artifacts
Using the smallest imaging plate possible and proper collimation, especially on small or thin patients, will eliminate operator errors.
True or False
True
What type of artifact is caused If the plate reader loads multiple imaging plates in a single cassette, only one of the plates will usually be extracted, leaving the other to be exposed multiple times. The result is similar to a conventional film/screen double-exposed cassette?
A. Imaging Receptor Artifacts
B. Plate Reader Artifacts
C. Image Processing Artifacts
D. Printer Artifacts
B. Plate Reader Artifacts
What type of exposure (underexposure or overexposure) produces quantum mottle.
Underexposure
Orientation of a grid so that the grid lines are parallel to the plate reader's laser scan lines results in the moiré pattern error.
True or False
True
What type of exposure (underexposure or overexposure) affects contrast.
Overexposure
The proper selection of technical factors is critical for both patient dose, image quality, and to ensure the appropriate production of light from the imaging plate.
True or False.
True
The major cause of noise in this system is ___________, and this is the main factor limiting quality.
A. Electronic noise
B. Electronic memory artifact
C. Incomplete charge transfer
A. Electronic noise
___________________will cause inaccuracies in pixel values in subsequent exposures, reducing image quality.
A. Electronic noise
B. Electronic memory artifact
C. Incomplete charge transfer
C. Incomplete charge transfer
Additionally, if exposures are taken in too rapid sequences, there may not be enough time for each previous exposure to transfer the entire signal, resulting in what is known as _________________.
A. Electronic noise
B. Electronic memory artifact
C. Incomplete charge transfer
B. Electronic memory artifact
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