Mosby's Exam Review Image
Production 2025 Questions and Answers
Which of the following reduces the scatter radiation reaching the detectors? - --
CORRECT ANSWER--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? - --CORRECT ANSWER--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: - --CORRECT ANSWER--thermionic emission
(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.)
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,The assignment of different generations to CT scanners is based on the
configuration of the: - --CORRECT ANSWER--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:
- --CORRECT ANSWER--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. - --CORRECT ANSWER--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: -
--CORRECT ANSWER--bow-tie filter
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,(The bow-tie filter used at the x-ray tube of a CT scanner absorbs a larger amount
of radiation at the periphery of the patient, where the part thickness is reduced.
The center of the patient is placed at the center of the filter, where the largest
amount of radiation is allowed to pass through. The use of this type of filter
attempts to compensate for the differences in thickness of the often oval-shaped
patient.)
The interaction between x-ray and matter that is responsible for the production of
the scatter radiation absorbed by the patient and detectors is: - --CORRECT
ANSWER--Compton effect
(In the Compton interaction, an x-ray photon ejects an outer-shell electron of an
atom. The photon loses some of its energy in the collision and then continues on
in a different, scattered direction. This interaction is the major source of the scatter
radiation involved in the formation of the CT image.)
The types of detectors used in computed tomography are:
1. Gas ionization
2. Stimulable phosphor
3. Scintillation - --CORRECT ANSWER--1 and 3 only
(The types of detectors used in computed tomography are scintillation and gas
ionization detectors. Both operate by measuring the amount of transmitted
radiation passed through the patient and transmitting this information to the
....COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED...TRUSTED & VERIFIED 3
, computer for image reconstruction. Newer MDCT systems utilize solid-state
scintillation detectors exclusively.)
Which of the following is used in gas ionization CT detectors? - --CORRECT
ANSWER--xenon
(Gases with high atomic numbers, such as xenon, are used in ionization-type CT
detector systems. The high atomic number of the xenon gas (Z = 54) increases the
incidence of interaction with x-ray photons, thus improving the efficiency of the
detector.)
Which of the following statements concerning the translate-rotate mode of CT
data acquisition is/are correct?1. 360-degree circular detector arrays are used.2.
Data are collected only during translation.3. Was used in first- and second-
generation CT scanners. - --CORRECT ANSWER--2 and 3 only
(The first- and second-generation CT scanners used a translate-rotate method of
data acquisition. The x-ray tube and detector(s) translated across the patient's head,
recording transmission measurements. The entire system then rotated 1 degree.
This process of translation-rotation then repeated itself for a total of 180 degrees.
First- and second-generation CT scanners used anywhere from 2 to 30 detectors.)
Which of the following terms accurately describes the type of x-ray beam used in a
third-generation CT scanner? - --CORRECT ANSWER--Fan beam
....COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED...TRUSTED & VERIFIED 4
Production 2025 Questions and Answers
Which of the following reduces the scatter radiation reaching the detectors? - --
CORRECT ANSWER--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? - --CORRECT ANSWER--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: - --CORRECT ANSWER--thermionic emission
(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.)
....COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED...TRUSTED & VERIFIED 1
,The assignment of different generations to CT scanners is based on the
configuration of the: - --CORRECT ANSWER--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:
- --CORRECT ANSWER--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. - --CORRECT ANSWER--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: -
--CORRECT ANSWER--bow-tie filter
....COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED...TRUSTED & VERIFIED 2
,(The bow-tie filter used at the x-ray tube of a CT scanner absorbs a larger amount
of radiation at the periphery of the patient, where the part thickness is reduced.
The center of the patient is placed at the center of the filter, where the largest
amount of radiation is allowed to pass through. The use of this type of filter
attempts to compensate for the differences in thickness of the often oval-shaped
patient.)
The interaction between x-ray and matter that is responsible for the production of
the scatter radiation absorbed by the patient and detectors is: - --CORRECT
ANSWER--Compton effect
(In the Compton interaction, an x-ray photon ejects an outer-shell electron of an
atom. The photon loses some of its energy in the collision and then continues on
in a different, scattered direction. This interaction is the major source of the scatter
radiation involved in the formation of the CT image.)
The types of detectors used in computed tomography are:
1. Gas ionization
2. Stimulable phosphor
3. Scintillation - --CORRECT ANSWER--1 and 3 only
(The types of detectors used in computed tomography are scintillation and gas
ionization detectors. Both operate by measuring the amount of transmitted
radiation passed through the patient and transmitting this information to the
....COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED...TRUSTED & VERIFIED 3
, computer for image reconstruction. Newer MDCT systems utilize solid-state
scintillation detectors exclusively.)
Which of the following is used in gas ionization CT detectors? - --CORRECT
ANSWER--xenon
(Gases with high atomic numbers, such as xenon, are used in ionization-type CT
detector systems. The high atomic number of the xenon gas (Z = 54) increases the
incidence of interaction with x-ray photons, thus improving the efficiency of the
detector.)
Which of the following statements concerning the translate-rotate mode of CT
data acquisition is/are correct?1. 360-degree circular detector arrays are used.2.
Data are collected only during translation.3. Was used in first- and second-
generation CT scanners. - --CORRECT ANSWER--2 and 3 only
(The first- and second-generation CT scanners used a translate-rotate method of
data acquisition. The x-ray tube and detector(s) translated across the patient's head,
recording transmission measurements. The entire system then rotated 1 degree.
This process of translation-rotation then repeated itself for a total of 180 degrees.
First- and second-generation CT scanners used anywhere from 2 to 30 detectors.)
Which of the following terms accurately describes the type of x-ray beam used in a
third-generation CT scanner? - --CORRECT ANSWER--Fan beam
....COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED...TRUSTED & VERIFIED 4
