Image Production - Mosby's Exam
Review 2025 Questions and Answers
Which of the following reduces the scatter radiation reaching the detectors?
A. Post-patient collimation
B. Pre-patient collimation
C. Pre-detector collimation
D. Both a and c - --CORRECT ANSWER--D. Both a and c
Pre-detector collimation and post-patient collimation are synonymous. Both terms
describe a device designed to remove scatter radiation before it reaches the
detector.
Which of the following is the primary interaction between x-ray photons and tissue
during computed tomography?
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,A.Bremsstrahlung
B.Characteristic
C. Compton effect
D. Coherent scatter - --CORRECT ANSWER--C. Compton effect
Owing to the high-energy beam used in CT, the Compton effect is the
predominant interaction between x-ray and matter. CT scanners use between 120
and 140 kVp, yielding x-ray energies with averages between 70 and 80 keV.
The process by which electrons are produced at the cathode of a CT x-ray tube is
known as:
A.rectification.
B. anode heel effect.
C. thermionic emission.
D. isotropic emission. - --CORRECT ANSWER--C. thermionic emission.
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,When the cathode of an x-ray tube is heated, electrons are released through the
process of thermionic emission. It is these electrons that are then accelerated
toward the anode for x-ray production.
The assignment of different generations to CT scanners is based on the
configuration of the:
A. patient and gantry.
B. tube and detectors.
C. anode and cathode.
D. tube and collimators. - --CORRECT ANSWER--B. tube and detectors.
CT scanners are often placed into one of several different "generations." The
differences in generations are based on the relationship of the tube and detectors
and the position of each during data acquisition.
When one is using a third-generation CT scanner, it is important that reference
detectors positioned at the peripheral portions of the detector array be exposed to:
A. homogeneous radiation.
B. unattenuated radiation.
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, C. monochromatic radiation.
D. remnant radiation. - --CORRECT ANSWER--B. unattenuated radiation
Reference detectors are used to measure incident radiation intensity. This
information is used by the computer during the calculation of the linear
attenuation coefficient. If the patient is placed incorrectly within the gantry, the
reference detectors may be partially blocked, causing an out-of-field artifact.
In 1979, the scientists __________ and __________ shared the Nobel Prize for
their research in computed tomography.
A. Watson and Crick
B. Olendorf and Hounsfield
C. Hounsfield and Cormack
D. Hounsfield and Ambrose - --CORRECT ANSWER--C. Hounsfield and
Cormack
Dr. Godfrey Hounsfield and Dr. Allan Cormack shared the Nobel Prize for their
work on the development of computed tomography in 1979.
The type of compensating filter used at the x-ray tube of a CT scanner is called a:
....COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED...TRUSTED & VERIFIED 4
Review 2025 Questions and Answers
Which of the following reduces the scatter radiation reaching the detectors?
A. Post-patient collimation
B. Pre-patient collimation
C. Pre-detector collimation
D. Both a and c - --CORRECT ANSWER--D. Both a and c
Pre-detector collimation and post-patient collimation are synonymous. Both terms
describe a device designed to remove scatter radiation before it reaches the
detector.
Which of the following is the primary interaction between x-ray photons and tissue
during computed tomography?
....COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED...TRUSTED & VERIFIED 1
,A.Bremsstrahlung
B.Characteristic
C. Compton effect
D. Coherent scatter - --CORRECT ANSWER--C. Compton effect
Owing to the high-energy beam used in CT, the Compton effect is the
predominant interaction between x-ray and matter. CT scanners use between 120
and 140 kVp, yielding x-ray energies with averages between 70 and 80 keV.
The process by which electrons are produced at the cathode of a CT x-ray tube is
known as:
A.rectification.
B. anode heel effect.
C. thermionic emission.
D. isotropic emission. - --CORRECT ANSWER--C. thermionic emission.
....COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED...TRUSTED & VERIFIED 2
,When the cathode of an x-ray tube is heated, electrons are released through the
process of thermionic emission. It is these electrons that are then accelerated
toward the anode for x-ray production.
The assignment of different generations to CT scanners is based on the
configuration of the:
A. patient and gantry.
B. tube and detectors.
C. anode and cathode.
D. tube and collimators. - --CORRECT ANSWER--B. tube and detectors.
CT scanners are often placed into one of several different "generations." The
differences in generations are based on the relationship of the tube and detectors
and the position of each during data acquisition.
When one is using a third-generation CT scanner, it is important that reference
detectors positioned at the peripheral portions of the detector array be exposed to:
A. homogeneous radiation.
B. unattenuated radiation.
....COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED...TRUSTED & VERIFIED 3
, C. monochromatic radiation.
D. remnant radiation. - --CORRECT ANSWER--B. unattenuated radiation
Reference detectors are used to measure incident radiation intensity. This
information is used by the computer during the calculation of the linear
attenuation coefficient. If the patient is placed incorrectly within the gantry, the
reference detectors may be partially blocked, causing an out-of-field artifact.
In 1979, the scientists __________ and __________ shared the Nobel Prize for
their research in computed tomography.
A. Watson and Crick
B. Olendorf and Hounsfield
C. Hounsfield and Cormack
D. Hounsfield and Ambrose - --CORRECT ANSWER--C. Hounsfield and
Cormack
Dr. Godfrey Hounsfield and Dr. Allan Cormack shared the Nobel Prize for their
work on the development of computed tomography in 1979.
The type of compensating filter used at the x-ray tube of a CT scanner is called a:
....COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED...TRUSTED & VERIFIED 4
