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20 Cards in this Set
- Front
- Back
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Using a __________________ reconstruction filter would decrease the appearance of noise in a CT image. |
d. 3 only
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A __________________ scan uses only a single projection.
1. conventional, or serial 2. helical 3. localizer a. 1 only b. 2 only c. 3 only d. 1, 2 & 3 |
c. 3 only
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Which of the following statements is FALSE regarding 3D SSD?
a. helical image data is well suited for 3D SSD because there is minimal misregistration or gaps b. the volume data, from which 3D SSD is generated, is created by combining transverse, sagittal, and coronal reconstructions. c. the tissue surface may be selected by using a threshold value equal to the tissue's CT number d. patient motion during the scan is detrimental to the quality of the 3D images. |
b. the volume data, from which 3D SSD is generated, is created by combining transverse, sagittal, and coronal reconstructions.
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Which type(s) of storage media may hold CT image data?
1. internal hard disk 2. CD 3. re-writable optical disk a. 1 only b. 2 only c. 3 only d. 1, 2 & 3 |
d. 1, 2 & 3
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______________ may have to be edited out from the data set to get a diagnostic MIP of a CTA exam.
a. Iodinated contrast media b. Vessels of interest c. Air d. Bones |
d. Bones
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Which of the following is NOT an advantage of a helical study compared to a conventional, serial CT study?
a. minimal anatomical misregistration sometimes caused by inconsistent breath-holding b. shorter total exam time c. can retrospectively reconstruct a slice at any arbitrary position d. offers the best image quality for a brain exam |
d. offers the best image quality for a brain exam
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Which of the following utilizes convolution?
1. 3D SSD 2. Fourier transform 3. filtered back projection a. 1 only b. 2 only c. 3 only d. 1, 2 & 3 |
c. 3 only
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In which technique are tissues other than the surface of a structure excluded by setting a threshold value and eliminating pixels above or below that threshold?
a. volume rendering b. multi-planar reconstruction c. maximum intensity projection d. 3D shaded Surface Display |
d. 3D shaded Surface Display
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From which of the following can the most diagnostic multi-planar reconstructions be generated?
1. stacked transverse images from a helical scan 2. stacked transverse images from a conventional, serial scan. 3. stacked localizer images a. 1 only b. 2 only c. 3 only d. 1, 2 & 3 |
a. 1 only
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The actual attenuation data measured by the detectors from all projections during a scan is contained in CT _______________ data
1. image 2. convolved 3. raw a. 1 only b. 2 only c. 3 only d. 1, 2 & 3 |
c. 3 only
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Which of the following is TRUE regarding the slice thickness of an image reconstructed from a helical scan?
1. on a multi-row detector scanner, the thickness is equal to the beam collimation 2. on a single-row detector scanner, the thickness is equal to the beam collimation 3. on a single-row detector scanner, the thickness can be varied retrospectively a. 1 only b. 2 only c. 2 & 3 d. 1, 2 & 3 |
b. 2 only
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A retrospective reconstruction, in which the reconstruction field-of-view is varied, uses:
a. a reconstructed image in the sagittal plane b. CT raw data c. more photons d. CT image data |
b. CT raw data
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Which of the following is common to both a localizer scan and a conventional, serial CT scan?
a. they both produce digital images b. the patient table moves at a constant velocity c. they both produce cross-sectional images d. the x-ray tube makes complete 360° rotations |
a. they both produce digital images
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Which of the following statements is TRUE?
1. the amplified electrical signal obtained from the detectors must be digitized 2. digital CT images are numerical representations of cross-sectional anatomy 3. digital signals may be formed by sampling analog signals at discrete time intervals a. 1 only b. 2 only c. 3 only d. 1, 2 & 3 |
d. 1, 2 & 3
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______________________ is the mathematical process used by single-row detector scanners to reconstruct CT images from raw data.
a. Weighted averaging b. Filtered back projection c. the Fourier transform d. Integration of the area under the curve |
b. Filtered back projection
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3D shaded surface displays are performed on CT:
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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A pixel is a:
a. bright artifact on a film b. single 3D volume element within a volume of anatomical data c. single 2D picture element within an image plane d. range of gray levels on a CT image |
c. single 2D picture element within an image plane
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The pencil thin section of the x-ray fan beam that strikes a single detector is called a:
a. line b. projection c. view d. ray |
d. ray
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A kernel is a:
a. component in the c-ray tube b. post-processing filter applied to image data c. type of detector d. filter applied to the CT raw data |
d. filter applied to the CT raw data
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An increase in _________________ does NOT occur in the resulting images when applying a sharp, or high-pass reconstruction filter during the image reconstruction of CT raw data.
1. contrast resolution 2. edge enhancement 3. the appearance of noise a. 1 only b. 2 only c. 3 only d. 1, 2 & 3 |
a. 1 only
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