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19 Cards in this Set
- Front
- Back
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CTA images come from a ___________________ scan. |
b. 2 only
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If an image matrix has 360 rows and 360 columns, how many pixels are there in the image?
a. 21,600 b. 129,600 c. 259,200 d. 379,800 |
b. 129,600
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The ___________________ determines the intensity of the laser beam in a laser camera.
1. intensifying grid 2. pixel values in the image data 3. magnifying power of the lens a. 1 only b. 2 only c. 3 only d. 1, 2 & 3 |
b. 2 only
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Which of the following is a reconstruction technique applied to the raw data after the primary reconstruction has already been accomplished?
a. maximum intensity projection b. volume rendering c. retrospective reconstruction d. multi-planar reconstruction |
c. retrospective reconstruction
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What does convolution do to the image quality when it is added to the back projection reconstruction process?
a. normalizes the attenuation coefficients to ensure tissues are displayed with correct CT numbers. b. increases the number of projections thereby reducing streaking artifacts c. improves contrast resolution by reducing scatter radiation d. enhances important characteristics of attenuation profiles thus reducing streak and star artifacts. |
d. enhances important characteristics of attenuation profiles thus reducing streak and star artifacts.
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Which of the following may occur during the interscan delay of a conventional, or serial, CT scan performed on a continuous rotation scanner?
1. the table position is incremented 2. the tube continues to rotate in the same direction as during the scan 3. the tube assembly makes a 360° rotation a. 1 only b. 2 only c. 3 only d. 1, 2 & 3 |
d. 1, 2 & 3
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______________ allows helical data to be converted into planar raw data.
a. Retrospective reconstruction b. Interpolation c. Cone beam reconstruction d. Convolution |
b. Interpolation
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What is the most common type of film used for recording CT images?
a. thermal b. double emulsion c. single emulsion d. paper |
c. single emulsion
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A helical scan performed on a 64 slice MDCT scanner is reconstructed with:
a. back projection b. simple reconstruction because it is a single projection scan c. no reconstruction filter d. cone beam reconstruction |
d. cone beam reconstruction
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________________ yields an image that appears 3D but also shows anatomical details above and below the 3D surface.
a. SSD b. VR c. MIP d. Multi-planar reconstruction |
b. VR
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MDCT scanners capable of collecting 64 slices in a single rotation do NOT:
a. perform conventional CT scans b. perform helical CT scans c. use filtered back projection as their method of image reconstruction d. perform localizer scans |
c. use filtered back projection as their method of image reconstruction
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MIP images:
a. are most frequently used for visualizing air-filled spaces b. can NOT be run in a cine loop c. are most accurate when a large volume of interest is selected d. do NOT demonstrate detail beneath the brightest pixel |
d. do NOT demonstrate detail beneath the brightest pixel
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Multi-planar reconstructions are performed on which of the following?
1. image data 2. raw data 3. attenuation profiles a. 1 only b. 2 only c. 3 only d. 1, 2 & 3 |
a. 1 only
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The ________________ move(s) during a helical scan on a third-generation scanner.
1. x-ray tube 2. patient table 3. detector elements a. 1 only b. 2 only c. 3 only d. 1, 2 & 3 |
d. 1, 2 & 3
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A CT system manufacturer has a scanner in which the focal spot of the x-ray beam can move to two, slightly separated, distinct locations. What benefit does the dual focal spot provide compared to an identical scanner possessing a single focal spot?
1. the number of projections is doubled 2. the number of rays in a single projection is doubled 3. the patient dose is halved a. 1 only b. 2 only c. 3 only d. 1, 2 & 3 |
a. 1 only
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On a third-generation single-row detector scanner, if there are 715 detectors and there are 900 projections in a full rotation, how many samples of attenuation data are collected for the raw data of a single slice if the scan calls for an overscan of 400° rotation?
a. 286,000 b. 643,000 c. 715,000 d. 845,000 |
c. 715,000
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A smooth, or low-pass, reconstruction filter is typically NOT selected for a(n) ________________ exam.
a. pituitary b. kidneys c. liver d. internal auditory canals |
d. internal auditory canals
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In a ___________________, the highest pixel values from a stack of CTA images are projected along many "rays".
a. SSD b. MIP c. PR d. VR |
b. MIP
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The x-ray beam used in CT scanning is __________________ the patient's tissues.
1. reflected off of 2. attenuated by 3. generated by a. 1 only b. 2 only c. 3 only d. 1, 2 & 3 |
b. 2 only
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