CT TECHNOLOGISTS ACTUAL EXAM QUESTIONS WITH
ANSWERS GRADED A+ 2025/2026
The ability of the tube to withstand by product heat is called:
A. heat capacity
B. heat dissipation
C. thermal potential
D. thermal transference - A. Heat capacity
Regarding the detectors in the CT system, geometric efficiency is controlled primarily
by:
A. detector material
B. type of photodiode used
C. filtration
D. detector spacing and aperture - D. Detector spacing and aperture
Which of the following is a characteristic of xenon gas detectors?
A. Low efficiency
B. Sensitive to temperature and moisture
C. May exhibit afterglow
D. Also called scintillators - A. Low efficiency
Which component of the CT system converts the electric signal supplied by the
detectors into a digital format?
A. Photodiode
B. Array processor
C. Display processor
D. Analog to digital converter - D. Analog to digital converter
"A precise set of steps to be performed in a specific order to solve a problem"
describes:
A. an algorithm
B. beam attenuation
C. the mean of a random variable
D. the binomial probability formula - A. an algorithm
What is interpolation?
A. A technique for expressing waveform as a weighted sum of sines and cosines
B. An efficient algorithm used to compute DFT and its inverse
C. the difference between the first quartile and the third quartile. This is one way to
describe the spread of a set of data.
D. A mathematical method of estimating an unknown value using the known values on
either side of the unknown - D. a mathematical method of estimating an unknown value
using the known values on either side of the unknown
Which is an example of a computer input device?
,A. Microprocessor
B. Primary memory
C. CT detector mechanisms
D. Laser camera - C. CT detector mechanisms
The central processing unit performs what function?
A. dissipates excessive heat that builds up on the target material
B. interprets computer program instructions and sequences tasks
C. samples the detectors
D. restricts the xray beam into thin ribbons - B. interprets computer program instructions
and sequences tasks
All the thousands of bits of data acquired by the CT system with each scan are called?
A. Image data
B. Calibration vectors
C. Raw data
D. Ray sums - C. raw data
The DAS reads each arriving ray and measures how much of the beam has been
attenuated. This is:
A. a ray sum
B. a view
C. back projection
D. a sample - A. a ray sum
In CT image creation using a third generation design, a complete set of ray sums is
known as:
A. convolution equation
B. algorithm
C. spatial frequency filter
D. view - D. view
The process of converting the data from the attenuation profile to a matrix is known as:
A. reformation
B. archiving
C. back projection
D. referencing - C. back projection
The process of applying a filter function to an attenuation profile is known as:
A. data processing
B. convolution
C. archiving
D. reformation - B. convolution
Increasing the scan field of view:
A. increases the number of detector cells collecting data
, B. increases the range of HU displayed on the image
C. decreases the pixel size
D. decreases the display field of view - A. increases the number of detector cells
collecting data
What is the function of the digital to analog converters?
A. converts the data into shades of gray to be displayed
B. converts the digital signal from the computer into an analog signal for the display
monitor
C. converts the light emitted from crystal detectors into an electric current
D. converts the analog signal from the detectors to a digital signal for the computers - B.
converts the digital signal from the computer into an analog signal for the display
monitor
Why is it necessary to convert the digitized data from the reconstruction processor to
shades of gray?
A. to allow an HU to be assigned to each structure
B. to remove streak artifacts from the final image
C. to enhance the desirable aspects of the image and suppress the undesirable aspects
D. so that an image can be displayed on the monitor - D. so that an image can be
displayed on the monitor
What hounsfield values are in the naturally occurring range (not manmade):
A. -1,000 to 1,000
B. -600 to 0
C. 0 to 1200
D. -2,000 to 4,000 - A. -1,000 to 1,000
Decreasing the window width in a CT image decreases:
A. Slice thickness
B. mAs
C. the appearance of quantum mottle
D. the anatomic diversity displayed - D. the anatomic diversity displayed
The window width of a specific CT image is set at 300 and the level is set at 100. How is
a structure with a measurement of 280 HU displayed?
A. it is white
B. it is a light shade of gray
C. it is a dark shade of gray
D. it is black - A. it is white
If the main tissue of interest is liver, which of the following is the best approximate
window level setting?
A. -600
B. 0
C. 50
ANSWERS GRADED A+ 2025/2026
The ability of the tube to withstand by product heat is called:
A. heat capacity
B. heat dissipation
C. thermal potential
D. thermal transference - A. Heat capacity
Regarding the detectors in the CT system, geometric efficiency is controlled primarily
by:
A. detector material
B. type of photodiode used
C. filtration
D. detector spacing and aperture - D. Detector spacing and aperture
Which of the following is a characteristic of xenon gas detectors?
A. Low efficiency
B. Sensitive to temperature and moisture
C. May exhibit afterglow
D. Also called scintillators - A. Low efficiency
Which component of the CT system converts the electric signal supplied by the
detectors into a digital format?
A. Photodiode
B. Array processor
C. Display processor
D. Analog to digital converter - D. Analog to digital converter
"A precise set of steps to be performed in a specific order to solve a problem"
describes:
A. an algorithm
B. beam attenuation
C. the mean of a random variable
D. the binomial probability formula - A. an algorithm
What is interpolation?
A. A technique for expressing waveform as a weighted sum of sines and cosines
B. An efficient algorithm used to compute DFT and its inverse
C. the difference between the first quartile and the third quartile. This is one way to
describe the spread of a set of data.
D. A mathematical method of estimating an unknown value using the known values on
either side of the unknown - D. a mathematical method of estimating an unknown value
using the known values on either side of the unknown
Which is an example of a computer input device?
,A. Microprocessor
B. Primary memory
C. CT detector mechanisms
D. Laser camera - C. CT detector mechanisms
The central processing unit performs what function?
A. dissipates excessive heat that builds up on the target material
B. interprets computer program instructions and sequences tasks
C. samples the detectors
D. restricts the xray beam into thin ribbons - B. interprets computer program instructions
and sequences tasks
All the thousands of bits of data acquired by the CT system with each scan are called?
A. Image data
B. Calibration vectors
C. Raw data
D. Ray sums - C. raw data
The DAS reads each arriving ray and measures how much of the beam has been
attenuated. This is:
A. a ray sum
B. a view
C. back projection
D. a sample - A. a ray sum
In CT image creation using a third generation design, a complete set of ray sums is
known as:
A. convolution equation
B. algorithm
C. spatial frequency filter
D. view - D. view
The process of converting the data from the attenuation profile to a matrix is known as:
A. reformation
B. archiving
C. back projection
D. referencing - C. back projection
The process of applying a filter function to an attenuation profile is known as:
A. data processing
B. convolution
C. archiving
D. reformation - B. convolution
Increasing the scan field of view:
A. increases the number of detector cells collecting data
, B. increases the range of HU displayed on the image
C. decreases the pixel size
D. decreases the display field of view - A. increases the number of detector cells
collecting data
What is the function of the digital to analog converters?
A. converts the data into shades of gray to be displayed
B. converts the digital signal from the computer into an analog signal for the display
monitor
C. converts the light emitted from crystal detectors into an electric current
D. converts the analog signal from the detectors to a digital signal for the computers - B.
converts the digital signal from the computer into an analog signal for the display
monitor
Why is it necessary to convert the digitized data from the reconstruction processor to
shades of gray?
A. to allow an HU to be assigned to each structure
B. to remove streak artifacts from the final image
C. to enhance the desirable aspects of the image and suppress the undesirable aspects
D. so that an image can be displayed on the monitor - D. so that an image can be
displayed on the monitor
What hounsfield values are in the naturally occurring range (not manmade):
A. -1,000 to 1,000
B. -600 to 0
C. 0 to 1200
D. -2,000 to 4,000 - A. -1,000 to 1,000
Decreasing the window width in a CT image decreases:
A. Slice thickness
B. mAs
C. the appearance of quantum mottle
D. the anatomic diversity displayed - D. the anatomic diversity displayed
The window width of a specific CT image is set at 300 and the level is set at 100. How is
a structure with a measurement of 280 HU displayed?
A. it is white
B. it is a light shade of gray
C. it is a dark shade of gray
D. it is black - A. it is white
If the main tissue of interest is liver, which of the following is the best approximate
window level setting?
A. -600
B. 0
C. 50
