CT EXAM #2 QUESTIONS WITH
COMPLETE ANSWERS
Volume acquisition scanners are based on:
1. slice by slice data acquisition
2. Slip ring technology
3. continuous rotation of the x-ray tube
A. 1 and 2
B. 1 and 3
C. 2 and 3
D. All are correct - Answer-C. 2 and 3
Absorption efficiency refers to how efficiently x-ray photons are captured by the
detectors
True or false - Answer-True
In multidetector scanning, which of the following determines slice thickness?
A. pre-patient collimators
B. post patient collimators
C. image reconstruction parameters
D. detector type - Answer-C. Image reconstruction parameters
Window level refers to:
1. midpoint in a range of CT numbers
2. image contrast
3. image brightness
A. 1 and 2
B. 1 and 3
C. 1
D. 1 2 and 3 - Answer-B. 1 and 3
As pitch increases, patient dose _______ - Answer-Decreases
The typical modern CT scanner generator converts
A. low voltage AC to high voltage DC
B. low voltage DC to high voltage DC
, C. high voltage DC to low voltage DC
D. low voltage DC to high voltage AC - Answer-A. low voltage AC to high voltage DC
- Answer-
All spiral helical scanners incorporate copper brushes as a component of the slip ring
design
True or false - Answer-False
AS the display field of view (DFOV) decreases:
A. Noise increases
B. Spatial resolution increases
C. Spatial resolution decreases
A. 1 and 2
. 1 and 3
C. 2 and 3
D. All - Answer-A. 1 and 2
As post patient collimation decreases, slice thickness
A. decreases
B. increases
C.remains the same
D. doubles - Answer-A. decreases
The window width determines the :
A. image density
B. image contrast
C. voxels depth
D. voxel width - Answer-B. image contrast
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 - Answer-C -> single row detector scanners and scanners
that have up to four parallel detector rows may use filtered back projection for image
reconstruction. All MDCT scanners that have more than four parallel rows of detectors
apply cone beam reconstruction so that cone beam artifacts are not created in the final
images. And, iterative reconstruction techniques may also be applied.
A retrospective reconstruction, in which the reconstruction field of view is varied, uses:
COMPLETE ANSWERS
Volume acquisition scanners are based on:
1. slice by slice data acquisition
2. Slip ring technology
3. continuous rotation of the x-ray tube
A. 1 and 2
B. 1 and 3
C. 2 and 3
D. All are correct - Answer-C. 2 and 3
Absorption efficiency refers to how efficiently x-ray photons are captured by the
detectors
True or false - Answer-True
In multidetector scanning, which of the following determines slice thickness?
A. pre-patient collimators
B. post patient collimators
C. image reconstruction parameters
D. detector type - Answer-C. Image reconstruction parameters
Window level refers to:
1. midpoint in a range of CT numbers
2. image contrast
3. image brightness
A. 1 and 2
B. 1 and 3
C. 1
D. 1 2 and 3 - Answer-B. 1 and 3
As pitch increases, patient dose _______ - Answer-Decreases
The typical modern CT scanner generator converts
A. low voltage AC to high voltage DC
B. low voltage DC to high voltage DC
, C. high voltage DC to low voltage DC
D. low voltage DC to high voltage AC - Answer-A. low voltage AC to high voltage DC
- Answer-
All spiral helical scanners incorporate copper brushes as a component of the slip ring
design
True or false - Answer-False
AS the display field of view (DFOV) decreases:
A. Noise increases
B. Spatial resolution increases
C. Spatial resolution decreases
A. 1 and 2
. 1 and 3
C. 2 and 3
D. All - Answer-A. 1 and 2
As post patient collimation decreases, slice thickness
A. decreases
B. increases
C.remains the same
D. doubles - Answer-A. decreases
The window width determines the :
A. image density
B. image contrast
C. voxels depth
D. voxel width - Answer-B. image contrast
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 - Answer-C -> single row detector scanners and scanners
that have up to four parallel detector rows may use filtered back projection for image
reconstruction. All MDCT scanners that have more than four parallel rows of detectors
apply cone beam reconstruction so that cone beam artifacts are not created in the final
images. And, iterative reconstruction techniques may also be applied.
A retrospective reconstruction, in which the reconstruction field of view is varied, uses:
