Radiographic Imaging and Exposure 2026/2027 | Fauber's 7th
Edition Study Guide, Radiologic Technology Exam Prep,
Practice Questions with Answers & Rationales, Radiation
Production, X-Ray Beam, Image Formation, Radiographic
Quality, Digital Imaging, Image Receptors, Image Processing,
Exposure Technique Factors, Scatter Control, Exposure
Technique Selection, Fluoroscopy, Radiation Protection &
ARRT Exam Prep
Question 1: Which exposure factor primarily controls the quantity of x-ray
photons produced in the x-ray tube?
A. Kilovoltage peak (kVp)
B. Milliampere-seconds (mAs)
C. Focal spot size
D. Source-to-image distance (SID)
CORRECT ANSWER: B. Milliampere-seconds (mAs)
Rationale: mAs determines the number of electrons flowing from cathode to
anode per unit time and therefore directly controls the quantity of x-ray photons
produced. kVp primarily controls photon energy and penetrability, focal spot size
affects spatial resolution, and SID affects beam intensity via the inverse square
law.
Question 2: According to the inverse square law, if the source-to-image distance
is doubled, the beam intensity at the image receptor will:
A. Double
B. Remain unchanged
C. Decrease to one-half
D. Decrease to one-quarter
CORRECT ANSWER: D. Decrease to one-quarter
Rationale: The inverse square law states that intensity is inversely proportional to
the square of the distance. Doubling the distance increases the denominator by a
factor of four, reducing intensity to one-quarter of its original value.
Question 3: Which of the following is the primary function of the anode in a
rotating anode x-ray tube?
,A. To emit electrons through thermionic emission
B. To focus the electron beam
C. To decelerate electrons and produce x-rays
D. To filter low-energy photons
CORRECT ANSWER: C. To decelerate electrons and produce x-rays
Rationale: The anode serves as the target where high-speed electrons are
abruptly decelerated, converting kinetic energy into x-ray photons via
bremsstrahlung and characteristic interactions. The cathode emits electrons, the
focusing cup directs them, and filtration occurs at the tube housing or collimator.
Question 4: The discrete portion of the x-ray emission spectrum is produced by
which interaction?
A. Bremsstrahlung interactions
B. Characteristic interactions
C. Compton scattering
D. Photoelectric absorption
CORRECT ANSWER: B. Characteristic interactions
Rationale: Characteristic x-rays are produced when an incident electron ejects an
inner-shell electron and an outer-shell electron fills the vacancy, emitting a
photon with energy equal to the binding energy difference. This produces
discrete, element-specific peaks. Bremsstrahlung produces a continuous
spectrum.
Question 5: Which exposure factor change will increase x-ray beam
penetrability without increasing patient dose?
A. Increasing mAs
B. Increasing kVp
C. Decreasing SID
D. Increasing filtration
CORRECT ANSWER: B. Increasing kVp
Rationale: Increasing kVp raises the average energy of the x-ray beam, improving
penetrability and reducing the proportion of photons absorbed in the patient.
,While increasing mAs raises dose proportionally, increasing kVp can often allow a
reduction in mAs to maintain receptor exposure, potentially lowering dose.
Question 6: The term "differential absorption" refers to:
A. The difference in x-ray absorption between bone and soft tissue
B. The variation in photon energy across the beam
C. The attenuation of x-rays by the collimator
D. The scattering of photons within the patient
CORRECT ANSWER: A. The difference in x-ray absorption between bone and soft
tissue
Rationale: Differential absorption describes how different tissues attenuate x-rays
to varying degrees based on atomic number, density, and thickness. This
difference is what creates subject contrast and allows anatomic structures to be
visualized on the radiograph.
Question 7: Which of the following contributes to the production of scattered
radiation in radiography?
A. Photoelectric absorption
B. Compton scattering
C. Pair production
D. Coherent scattering
CORRECT ANSWER: B. Compton scattering
Rationale: Compton scattering occurs when an incident x-ray photon interacts
with an outer-shell electron, ejecting it and redirecting the photon with reduced
energy. This redirected photon travels in a different direction and is the primary
source of scattered radiation in diagnostic radiography.
Question 8: The primary purpose of beam restriction in radiography is to:
A. Increase the number of x-ray photons reaching the receptor
B. Reduce patient dose and improve image contrast
C. Increase the energy of the x-ray beam
D. Decrease the source-to-image distance
CORRECT ANSWER: B. Reduce patient dose and improve image contrast
, Rationale: Collimating the beam limits the irradiated area, reducing patient dose
and the volume of tissue that can produce scatter. Less scatter reaching the
receptor improves contrast by reducing fog.
Question 9: Which of the following is an advantage of using a high kVp
technique?
A. Increased patient dose
B. Increased subject contrast
C. Decreased scatter production
D. Increased latitude and decreased patient dose
CORRECT ANSWER: D. Increased latitude and decreased patient dose
Rationale: High kVp techniques produce a more penetrating beam with greater
exposure latitude, meaning a wider range of tissue densities can be adequately
visualized. Because fewer photons are absorbed in the patient, dose can be
reduced while maintaining receptor exposure.
Question 10: The active layer of a computed radiography (CR) imaging plate is
typically made of:
A. Amorphous selenium
B. Cesium iodide
C. Barium fluorohalide with europium
D. Silicon dioxide
CORRECT ANSWER: C. Barium fluorohalide with europium
Rationale: CR imaging plates use a photostimulable phosphor layer, commonly
barium fluorohalide doped with europium, which traps electrons in metastable
states when exposed to x-rays. Laser stimulation releases the stored energy as
visible light for readout.
Question 11: In digital radiography, the term "detective quantum efficiency"
(DQE) describes:
A. The ratio of input signal to output noise
B. The efficiency of converting x-ray photons into a useful signal
Edition Study Guide, Radiologic Technology Exam Prep,
Practice Questions with Answers & Rationales, Radiation
Production, X-Ray Beam, Image Formation, Radiographic
Quality, Digital Imaging, Image Receptors, Image Processing,
Exposure Technique Factors, Scatter Control, Exposure
Technique Selection, Fluoroscopy, Radiation Protection &
ARRT Exam Prep
Question 1: Which exposure factor primarily controls the quantity of x-ray
photons produced in the x-ray tube?
A. Kilovoltage peak (kVp)
B. Milliampere-seconds (mAs)
C. Focal spot size
D. Source-to-image distance (SID)
CORRECT ANSWER: B. Milliampere-seconds (mAs)
Rationale: mAs determines the number of electrons flowing from cathode to
anode per unit time and therefore directly controls the quantity of x-ray photons
produced. kVp primarily controls photon energy and penetrability, focal spot size
affects spatial resolution, and SID affects beam intensity via the inverse square
law.
Question 2: According to the inverse square law, if the source-to-image distance
is doubled, the beam intensity at the image receptor will:
A. Double
B. Remain unchanged
C. Decrease to one-half
D. Decrease to one-quarter
CORRECT ANSWER: D. Decrease to one-quarter
Rationale: The inverse square law states that intensity is inversely proportional to
the square of the distance. Doubling the distance increases the denominator by a
factor of four, reducing intensity to one-quarter of its original value.
Question 3: Which of the following is the primary function of the anode in a
rotating anode x-ray tube?
,A. To emit electrons through thermionic emission
B. To focus the electron beam
C. To decelerate electrons and produce x-rays
D. To filter low-energy photons
CORRECT ANSWER: C. To decelerate electrons and produce x-rays
Rationale: The anode serves as the target where high-speed electrons are
abruptly decelerated, converting kinetic energy into x-ray photons via
bremsstrahlung and characteristic interactions. The cathode emits electrons, the
focusing cup directs them, and filtration occurs at the tube housing or collimator.
Question 4: The discrete portion of the x-ray emission spectrum is produced by
which interaction?
A. Bremsstrahlung interactions
B. Characteristic interactions
C. Compton scattering
D. Photoelectric absorption
CORRECT ANSWER: B. Characteristic interactions
Rationale: Characteristic x-rays are produced when an incident electron ejects an
inner-shell electron and an outer-shell electron fills the vacancy, emitting a
photon with energy equal to the binding energy difference. This produces
discrete, element-specific peaks. Bremsstrahlung produces a continuous
spectrum.
Question 5: Which exposure factor change will increase x-ray beam
penetrability without increasing patient dose?
A. Increasing mAs
B. Increasing kVp
C. Decreasing SID
D. Increasing filtration
CORRECT ANSWER: B. Increasing kVp
Rationale: Increasing kVp raises the average energy of the x-ray beam, improving
penetrability and reducing the proportion of photons absorbed in the patient.
,While increasing mAs raises dose proportionally, increasing kVp can often allow a
reduction in mAs to maintain receptor exposure, potentially lowering dose.
Question 6: The term "differential absorption" refers to:
A. The difference in x-ray absorption between bone and soft tissue
B. The variation in photon energy across the beam
C. The attenuation of x-rays by the collimator
D. The scattering of photons within the patient
CORRECT ANSWER: A. The difference in x-ray absorption between bone and soft
tissue
Rationale: Differential absorption describes how different tissues attenuate x-rays
to varying degrees based on atomic number, density, and thickness. This
difference is what creates subject contrast and allows anatomic structures to be
visualized on the radiograph.
Question 7: Which of the following contributes to the production of scattered
radiation in radiography?
A. Photoelectric absorption
B. Compton scattering
C. Pair production
D. Coherent scattering
CORRECT ANSWER: B. Compton scattering
Rationale: Compton scattering occurs when an incident x-ray photon interacts
with an outer-shell electron, ejecting it and redirecting the photon with reduced
energy. This redirected photon travels in a different direction and is the primary
source of scattered radiation in diagnostic radiography.
Question 8: The primary purpose of beam restriction in radiography is to:
A. Increase the number of x-ray photons reaching the receptor
B. Reduce patient dose and improve image contrast
C. Increase the energy of the x-ray beam
D. Decrease the source-to-image distance
CORRECT ANSWER: B. Reduce patient dose and improve image contrast
, Rationale: Collimating the beam limits the irradiated area, reducing patient dose
and the volume of tissue that can produce scatter. Less scatter reaching the
receptor improves contrast by reducing fog.
Question 9: Which of the following is an advantage of using a high kVp
technique?
A. Increased patient dose
B. Increased subject contrast
C. Decreased scatter production
D. Increased latitude and decreased patient dose
CORRECT ANSWER: D. Increased latitude and decreased patient dose
Rationale: High kVp techniques produce a more penetrating beam with greater
exposure latitude, meaning a wider range of tissue densities can be adequately
visualized. Because fewer photons are absorbed in the patient, dose can be
reduced while maintaining receptor exposure.
Question 10: The active layer of a computed radiography (CR) imaging plate is
typically made of:
A. Amorphous selenium
B. Cesium iodide
C. Barium fluorohalide with europium
D. Silicon dioxide
CORRECT ANSWER: C. Barium fluorohalide with europium
Rationale: CR imaging plates use a photostimulable phosphor layer, commonly
barium fluorohalide doped with europium, which traps electrons in metastable
states when exposed to x-rays. Laser stimulation releases the stored energy as
visible light for readout.
Question 11: In digital radiography, the term "detective quantum efficiency"
(DQE) describes:
A. The ratio of input signal to output noise
B. The efficiency of converting x-ray photons into a useful signal
