Computed Tomography (CT) Scan Quiz
Computer tomography scans commonly known as CT scans make use of computer-processed combinations of many X-ray measurements taken at different angles. Take up the quiz below and gauge you knowledge on CT scans. All the best.
- 1.Using _________ reconstruction filter would decrease the appearance of noise in a CT image.1. no2. a sharp3. a smooth
- A.
1 only
- B.
2 only
- C.
2&3
- D.
3 only
- 2.A ___________ scan uses only a single projection.1. conventional, or serial2. helical3. localizer
- A.
1 only
- B.
2 only
- C.
3 only
- D.
1,2,&3
- 3.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 the 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
- 4.Which type(s) of storage media may hold CT image data?1. internal hard disk2. CD3. re-writable optical disk
- A.
1 only
- B.
2 only
- C.
3 only
- D.
1,2,& 3
- 5.____________ may have to be edited from the data set to get a diagnostic MIP of a CTA exam.
- A.
Iodinated contrast media
- B.
Vessels of inetrest
- C.
Air
- D.
Bones
- 6.Which of the following is NOT an advantage of a helical study compared to a conventional, serial CT study?
- A.
Minimal anatomical mis-registration 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
- 7.Which of the following utilizes convolution?1. 3D SSD2. fourier transform3. filtered back projection
- A.
1 only
- B.
2 only
- C.
3 only
- D.
1, 2, & 3
- 8.In which technique are tissues other than the surface of 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
- 9.From which of the following can the most diagnostic multi-planar reconstructions be generated?1. stacked transverse images from a helical scan2. stacked transverse images from a conventional, serial scan3. stacked localizer images
- A.
1 only
- B.
2 only
- C.
3 only
- D.
1, 2, & 3
- 10.The actual attenuation data measured by the detectors from all projections during a scan is contained in CT ____________ data.1. image2. convolved3. raw
- A.
1 only
- B.
2 only
- C.
3 only
- D.
1, 2, & 3
- 11.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
- 12.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
- 13.Which of the following is common to both localizer scan and a conventional, serial CT scan?
- A.
They both produce saggital 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 degree rotations
- 14.Which of the following statements are 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
- 15.___________________ is the mathematical process used by single row detector scanners to reconstruct CT image from raw data.
- A.
Weighted averaging
- B.
Filtered back projection
- C.
The fourier transform
- D.
Integration of the area under the curve
- 16.3D shaded surface displays are performed on CT:1. image data2. raw data3. attenuation profiles
- A.
1 only
- B.
2 only
- C.
3 only
- D.
1, 2, & 3
- 17.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 the image plane
- D.
Range of gray levels on a CT image
- 18.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
- 19.A kernel is a:
- A.
Component in the x-ray tube
- B.
Post-processing filter applied to image data
- C.
Type of detector
- D.
Filter applied to the CT raw data
- 20.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 resolution2. edge enhancement3. the appearance of noise
- A.
1 only
- B.
2 only
- C.
3 only
- D.
1, 2, & 3
- 21.CTA images come from a __________ scan.1. conventional, or serial2. helical3. localizer
- A.
1 only
- B.
2 only
- C.
3 only
- D.
1, 2, & 3
- 22.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
- 23.The ______________ determines the intensity of the laser beam in a laser camera.1. intensifying grid2. pixel values in the image data3. mgnifying power of the lens
- A.
1 only
- B.
2 only
- C.
3 only
- D.
1, 2 & 3
- 24.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
- 25.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
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