Computed Tomography for
Technologists 2nd Edition Exam
Review 2025 Questions and Answers
Which is NOT a synonym for the preliminary/localizer image taken at the start of a CT
examination?
A. Topogram
B. Scout
C. Scanogram
D. Spiral - ANSWER✔✔-D. Spiral
The ability of a system to differentiate, on the image, objects with similar densities is known as:
A. High contrast resolution
B. Low contrast resolution
C. Spatial resolution
D. Temporal resolution - ANSWER✔✔-B. Low contrast resolution
Each two dimensional square of data that make up the CT image is called a:
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,A. Pixel
B. Voxel
C. Matrix
D. Fragment - ANSWER✔✔-A. Pixel
How many pixels are contained in a 1,024 matrix image? A. 1,024
B. 2,048
C. 262,144
D. 1,048,576 - ANSWER✔✔-D. 1,048,576
Beam attenuation can be defined as:
A. The phenomenon by which artifacts result when lower energy photons are preferentially
absorbed, leaving only higher-intensity photons to strike the detector array.
B. Xray energy that is produced from bombarding a substance with fast moving electrons.
C. The ability of the detector to capture transmitted photons and change them to electronic signals.
D. The phenomenon by which an xray beam passing through a structure is decreased in intensity or
amount because of absorption and interaction with matter. - ANSWER✔✔-D. The phenomenon by
which an xray beam passing through a structure is decreased in intensity or amount because of
absorption and interaction with matter.
Which of the following is a low attenuation structure:
A. Iodine filled aorta
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,B. Rib
C. Trachea
D. Calcified arteries - ANSWER✔✔-C. Trachea
An object is slightly less dense than water. What is the expected hounsfield measurement?
A. -940
B. -10
C. 50
D. 850 - ANSWER✔✔-B. -10
Why does the administration of iodinated contrast media result in an enhanced image?
A. Iodinated contrast material increases the ability of the enhanced structure to attenuate the xray
beam.
B. Iodinated contrast material decreases the average photon energy of the xray beam; therefore more
photons are absorbed by the patient.
C. The administration of contrast material results in a smaller pixel, thereby increasing spatial
resolution, which results in an enhanced image.
D. - ANSWER✔✔-A. Iodinated contrast material increases the ability of the enhanced structure to
attenuate the xray beam.
The xray beam sources for CT produce xray energy that is polychromatic. This means:
A. When viewed by the naked eye, the beam exhibits many different colors.
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, B. It produce, as a byproduct, a substance known as polychlorinated biphenyl.
C. Photons contained in the beam are all of the same wavelength.
D. The beam comprises photons with varying energies. - ANSWER✔✔-D. The beam comprises
photons with varying energies.
An object that appears on the image but is not present in the object scanned is called a/n:
A. Artifact
B. Anomaly
C. Shadow
D. Ghost - ANSWER✔✔-A. Artifact
Which is an advantage of filtering the xray beam?
A. Filtering reduces the anode heat load
B. A filtered beam produces images with substantially less quantum mottle
C. Filtering the beam prevents energy from being converted to heat, therefore 100% of the energy is
converted to xrays.
D. Filtering reduces the radiation dose to the patient. - ANSWER✔✔-D. Filtering reduces the
radiation dose to the patient
Scan thickness is primarily important for the part it plays in:
A. Noise reduction
B. The contrast scale
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Technologists 2nd Edition Exam
Review 2025 Questions and Answers
Which is NOT a synonym for the preliminary/localizer image taken at the start of a CT
examination?
A. Topogram
B. Scout
C. Scanogram
D. Spiral - ANSWER✔✔-D. Spiral
The ability of a system to differentiate, on the image, objects with similar densities is known as:
A. High contrast resolution
B. Low contrast resolution
C. Spatial resolution
D. Temporal resolution - ANSWER✔✔-B. Low contrast resolution
Each two dimensional square of data that make up the CT image is called a:
FOR STUDY PURPOSES ONLY COPYRIGHT © 2025 ALL RIGHTS RESERVED 1
,A. Pixel
B. Voxel
C. Matrix
D. Fragment - ANSWER✔✔-A. Pixel
How many pixels are contained in a 1,024 matrix image? A. 1,024
B. 2,048
C. 262,144
D. 1,048,576 - ANSWER✔✔-D. 1,048,576
Beam attenuation can be defined as:
A. The phenomenon by which artifacts result when lower energy photons are preferentially
absorbed, leaving only higher-intensity photons to strike the detector array.
B. Xray energy that is produced from bombarding a substance with fast moving electrons.
C. The ability of the detector to capture transmitted photons and change them to electronic signals.
D. The phenomenon by which an xray beam passing through a structure is decreased in intensity or
amount because of absorption and interaction with matter. - ANSWER✔✔-D. The phenomenon by
which an xray beam passing through a structure is decreased in intensity or amount because of
absorption and interaction with matter.
Which of the following is a low attenuation structure:
A. Iodine filled aorta
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,B. Rib
C. Trachea
D. Calcified arteries - ANSWER✔✔-C. Trachea
An object is slightly less dense than water. What is the expected hounsfield measurement?
A. -940
B. -10
C. 50
D. 850 - ANSWER✔✔-B. -10
Why does the administration of iodinated contrast media result in an enhanced image?
A. Iodinated contrast material increases the ability of the enhanced structure to attenuate the xray
beam.
B. Iodinated contrast material decreases the average photon energy of the xray beam; therefore more
photons are absorbed by the patient.
C. The administration of contrast material results in a smaller pixel, thereby increasing spatial
resolution, which results in an enhanced image.
D. - ANSWER✔✔-A. Iodinated contrast material increases the ability of the enhanced structure to
attenuate the xray beam.
The xray beam sources for CT produce xray energy that is polychromatic. This means:
A. When viewed by the naked eye, the beam exhibits many different colors.
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, B. It produce, as a byproduct, a substance known as polychlorinated biphenyl.
C. Photons contained in the beam are all of the same wavelength.
D. The beam comprises photons with varying energies. - ANSWER✔✔-D. The beam comprises
photons with varying energies.
An object that appears on the image but is not present in the object scanned is called a/n:
A. Artifact
B. Anomaly
C. Shadow
D. Ghost - ANSWER✔✔-A. Artifact
Which is an advantage of filtering the xray beam?
A. Filtering reduces the anode heat load
B. A filtered beam produces images with substantially less quantum mottle
C. Filtering the beam prevents energy from being converted to heat, therefore 100% of the energy is
converted to xrays.
D. Filtering reduces the radiation dose to the patient. - ANSWER✔✔-D. Filtering reduces the
radiation dose to the patient
Scan thickness is primarily important for the part it plays in:
A. Noise reduction
B. The contrast scale
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