HESI Radiography Exit Exam Master Questions
Answers & Rationales 2026
The Radiography HESI / ARRT Certification Exam is a comprehensive, computer-
based evaluation that assesses your entry-level competence as a radiologic
technologist. To pass, you must demonstrate the clinical reasoning required to
safely operate imaging equipment, protect patients and yourself from radiation,
and produce diagnostic-quality images under various clinical conditions.
1. Which of the following digital radiography artifacts is caused by an incomplete erasure
of a computed radiography (CR) imaging plate?
A) Moire pattern
B) Ghosting
C) Vignetting
D) Quantum mottle
Rationale: Ghosting (or image lag) occurs when a previous latent image is not fully
erased from the phosphor plate, leaving a faint shadow on the subsequent image.
2. What is the active ingredient in the crystal layer of an optically stimulated luminescence
(OSL) dosimeter?
A) Lithium fluoride
B) Aluminum oxide
C) Cesium iodide
D) Silver halide
Rationale: OSL dosimeters use aluminum oxide (\(Al_{2}O_{3}\)) to detect and record
radiation exposure when stimulated by a laser light.
3. Which projection of the lumbar spine best demonstrates the intervertebral foramina?
A) AP projection
B) PA oblique projection
C) True lateral projection
D) 45-degree oblique projection
Rationale: The intervertebral foramina of the lumbar spine open up at a true 90-degree
angle to the midsagittal plane, making them visible only on a lateral view.
4. What is the primary purpose of a baseline grid ratio increase from 5:1 to 12:1?
A) To decrease patient skin dose
B) To increase spatial resolution sharpness
C) To clean up more scatter radiation
D) To eliminate structural magnification
, Rationale: Higher grid ratios have narrower lead strips placed closer together, which
increases their ability to filter out scattered x-ray photons.
5. Which specific structure must be seen in profile on a diagnostic lateral projection of the
calcaneus?
A) Cuboid bone
B) Sustentaculum tali
C) Medial cuneiform
D) Sinus tarsi
Rationale: A true lateral calcaneus projection places the sustentaculum tali in profile on
the medial aspect of the bone structure.
6. What type of syringe injection introduces contrast media or medication directly into the
space surrounding the spinal cord?
A) Intravenous injection
B) Intraarterial injection
C) Intramuscular injection
D) Intrathecal injection
Rationale: An intrathecal injection delivers contrast directly into the subarachnoid space
during a myelogram procedure.
7. If a radiographer stands 3 feet from an x-ray tube and receives 12 mR of exposure,
what will the dose be at a distance of 6 feet?
A) 6 mR
B) 3 mR
C) 1.5 mR
D) 24 mR
Rationale: Doubly increasing the distance drops the intensity down to one-fourth (\(12 /
2^2 = 3\)) according to the Inverse Square Law.
8. Which positioning line must be placed parallel to the image receptor for an open-mouth
AP projection of the atlas and axis (C1-C2)?
A) A line from the lower edge of the upper incisors to the mastoid tip
B) Orbitomeatal line (OML)
C) Acanthiomeatal line (AML)
D) Mentomeatal line (MML)
Rationale: Aligning the lower edge of the upper teeth with the base of the skull ensures
that the upper incisors do not superimpose the dens.
9. Which type of biological effect is completely random and has a probability of occurrence
that is proportional to the dose received?
A) Deterministic effect
B) Tissue reaction effect
C) Stochastic effect
D) Threshold effect
Rationale: Stochastic effects (like cancer induction or genetic mutations) have no
minimum threshold dose; any exposure increases the risk.
10. What type of device converts visible light photons into an electrical signal inside a digital
indirect-capture DR flat-panel detector?
A) Amorphous selenium photoconductor
B) Amorphous silicon photodiode
, C) Cesium iodide scintillator
D) Barium fluorohalide phosphor
Rationale: Indirect DR systems use a scintillator to turn x-rays into light, then use an
amorphous silicon (\(a-Si\)) photodiode layer to convert that light into an electrical
signal.
11. What anatomical landmark corresponds directly to the structural level of the thyroid
cartilage?
A) C1-C2
B) C4-C5
C) C7-T1
D) T4-T5
Rationale: The thyroid cartilage (commonly called the Adam's apple) sits prominently at
the level of the fourth and fifth cervical vertebrae.
12. What does a high bit depth system guarantee for a digital image?
A) High spatial resolution pixel layout
B) Lower patient entry dose requirements
C) High contrast resolution (more gray shades)
D) Elimination of geometric magnification errors
Rationale: Bit depth (\(2^{n}\)) sets the maximum capacity of grayscales a pixel can
hold, maximizing the contrast resolution of the image.
13. Which of the following conditions represents an additive pathology that requires an
increase in exposure factors?
A) Pneumothorax
B) Atelectasis
C) Osteoporosis
D) Emphysema
Rationale: Atelectasis causes a collapse of lung tissue, making it denser and more
compact, which requires more radiation to penetrate.
14. What structural area of the stomach is best filled with barium when a patient is placed in
the LPO (Left Posterior Oblique) position?
A) Fundus
B) Pyloric canal
C) Duodenal bulb
D) Greater curvature
Rationale: In the LPO position, the fundus shifts to a dependent position, causing heavy
barium to settle into it while gas fills the body and pylorus.
15. What type of x-ray tube circuit device uses an induction motor to turn the anode disc at
high speeds?
A) Filament transformer
B) Stator and rotor assembly
C) Autotransformer unit
D) High-voltage rectifier matrix
Rationale: The stator is located outside the glass envelope and uses electromagnetic
force to turn the internal rotor and anode shaft.
16. Which medical condition is characterized by a dangerous drop in blood pressure
accompanied by a rapid heart rate due to a severe loss of blood volume?
, A) Anaphylactic shock
B) Cardiogenic shock
C) Hypovolemic shock
D) Neurogenic shock
Rationale: Hypovolemic shock is caused by massive blood or fluid loss, which prevents
the heart from pumping enough blood to vital organs.
17. What type of grid error happens when a focused grid is tilted relative to the central ray
of the x-ray beam?
A) Off-center grid error
B) Off-distance grid error
C) Off-level grid error
D) Upside-down grid error
Rationale: An off-level grid error occurs if the grid is tilted or if the tube is angled across
the grid lines, causing a uniform loss of exposure.
18. What basic positioning step is required to demonstrate the olecranon process in profile?
A) AP projection of the elbow
B) Medial oblique projection of the elbow
C) Lateral oblique projection of the elbow
D) True lateral projection of the elbow
Rationale: Flexing the elbow 90 degrees and placing it in a true lateral position projects
the olecranon process directly into profile posteriorly.
19. What type of cells are considered the least radiosensitive according to the law of
Bergonie and Tribondeau?
A) Stem cells
B) Nerve cells
C) Erythroblasts
D) Lymphocytes
Rationale: Highly specialized, mature cells that do not undergo regular cellular division
(like nerve and muscle cells) are highly radioresistant.
20. What is the function of the autotransformer inside a standard x-ray machine circuit?
A) Converts alternating current to direct current
B) Allows for the selection of the primary voltage level (kVp)
C) Heats up the filament wire to boil off electrons
D) Protects the circuit from electrical power surges
Rationale: The autotransformer operates on self-induction and lets the technologist step
up or step down the input voltage before it goes to the main step-up transformer.
21. Which projection of the skull will project the petrous ridges into the lower one-third of the
orbits?
A) AP projection (0-degree angle)
B) PA axial projection (Caldwell method)
C) Parietoacanthial projection (Waters method)
D) Submentovertex projection (SMV)
Rationale: A 15-degree caudad angle on a PA skull projection (Caldwell view) pushes
the dense petrous ridges down into the lower third of the eye orbits.
22. What basic processing tool adjusts the window level of a digital image during post-
processing review?
Answers & Rationales 2026
The Radiography HESI / ARRT Certification Exam is a comprehensive, computer-
based evaluation that assesses your entry-level competence as a radiologic
technologist. To pass, you must demonstrate the clinical reasoning required to
safely operate imaging equipment, protect patients and yourself from radiation,
and produce diagnostic-quality images under various clinical conditions.
1. Which of the following digital radiography artifacts is caused by an incomplete erasure
of a computed radiography (CR) imaging plate?
A) Moire pattern
B) Ghosting
C) Vignetting
D) Quantum mottle
Rationale: Ghosting (or image lag) occurs when a previous latent image is not fully
erased from the phosphor plate, leaving a faint shadow on the subsequent image.
2. What is the active ingredient in the crystal layer of an optically stimulated luminescence
(OSL) dosimeter?
A) Lithium fluoride
B) Aluminum oxide
C) Cesium iodide
D) Silver halide
Rationale: OSL dosimeters use aluminum oxide (\(Al_{2}O_{3}\)) to detect and record
radiation exposure when stimulated by a laser light.
3. Which projection of the lumbar spine best demonstrates the intervertebral foramina?
A) AP projection
B) PA oblique projection
C) True lateral projection
D) 45-degree oblique projection
Rationale: The intervertebral foramina of the lumbar spine open up at a true 90-degree
angle to the midsagittal plane, making them visible only on a lateral view.
4. What is the primary purpose of a baseline grid ratio increase from 5:1 to 12:1?
A) To decrease patient skin dose
B) To increase spatial resolution sharpness
C) To clean up more scatter radiation
D) To eliminate structural magnification
, Rationale: Higher grid ratios have narrower lead strips placed closer together, which
increases their ability to filter out scattered x-ray photons.
5. Which specific structure must be seen in profile on a diagnostic lateral projection of the
calcaneus?
A) Cuboid bone
B) Sustentaculum tali
C) Medial cuneiform
D) Sinus tarsi
Rationale: A true lateral calcaneus projection places the sustentaculum tali in profile on
the medial aspect of the bone structure.
6. What type of syringe injection introduces contrast media or medication directly into the
space surrounding the spinal cord?
A) Intravenous injection
B) Intraarterial injection
C) Intramuscular injection
D) Intrathecal injection
Rationale: An intrathecal injection delivers contrast directly into the subarachnoid space
during a myelogram procedure.
7. If a radiographer stands 3 feet from an x-ray tube and receives 12 mR of exposure,
what will the dose be at a distance of 6 feet?
A) 6 mR
B) 3 mR
C) 1.5 mR
D) 24 mR
Rationale: Doubly increasing the distance drops the intensity down to one-fourth (\(12 /
2^2 = 3\)) according to the Inverse Square Law.
8. Which positioning line must be placed parallel to the image receptor for an open-mouth
AP projection of the atlas and axis (C1-C2)?
A) A line from the lower edge of the upper incisors to the mastoid tip
B) Orbitomeatal line (OML)
C) Acanthiomeatal line (AML)
D) Mentomeatal line (MML)
Rationale: Aligning the lower edge of the upper teeth with the base of the skull ensures
that the upper incisors do not superimpose the dens.
9. Which type of biological effect is completely random and has a probability of occurrence
that is proportional to the dose received?
A) Deterministic effect
B) Tissue reaction effect
C) Stochastic effect
D) Threshold effect
Rationale: Stochastic effects (like cancer induction or genetic mutations) have no
minimum threshold dose; any exposure increases the risk.
10. What type of device converts visible light photons into an electrical signal inside a digital
indirect-capture DR flat-panel detector?
A) Amorphous selenium photoconductor
B) Amorphous silicon photodiode
, C) Cesium iodide scintillator
D) Barium fluorohalide phosphor
Rationale: Indirect DR systems use a scintillator to turn x-rays into light, then use an
amorphous silicon (\(a-Si\)) photodiode layer to convert that light into an electrical
signal.
11. What anatomical landmark corresponds directly to the structural level of the thyroid
cartilage?
A) C1-C2
B) C4-C5
C) C7-T1
D) T4-T5
Rationale: The thyroid cartilage (commonly called the Adam's apple) sits prominently at
the level of the fourth and fifth cervical vertebrae.
12. What does a high bit depth system guarantee for a digital image?
A) High spatial resolution pixel layout
B) Lower patient entry dose requirements
C) High contrast resolution (more gray shades)
D) Elimination of geometric magnification errors
Rationale: Bit depth (\(2^{n}\)) sets the maximum capacity of grayscales a pixel can
hold, maximizing the contrast resolution of the image.
13. Which of the following conditions represents an additive pathology that requires an
increase in exposure factors?
A) Pneumothorax
B) Atelectasis
C) Osteoporosis
D) Emphysema
Rationale: Atelectasis causes a collapse of lung tissue, making it denser and more
compact, which requires more radiation to penetrate.
14. What structural area of the stomach is best filled with barium when a patient is placed in
the LPO (Left Posterior Oblique) position?
A) Fundus
B) Pyloric canal
C) Duodenal bulb
D) Greater curvature
Rationale: In the LPO position, the fundus shifts to a dependent position, causing heavy
barium to settle into it while gas fills the body and pylorus.
15. What type of x-ray tube circuit device uses an induction motor to turn the anode disc at
high speeds?
A) Filament transformer
B) Stator and rotor assembly
C) Autotransformer unit
D) High-voltage rectifier matrix
Rationale: The stator is located outside the glass envelope and uses electromagnetic
force to turn the internal rotor and anode shaft.
16. Which medical condition is characterized by a dangerous drop in blood pressure
accompanied by a rapid heart rate due to a severe loss of blood volume?
, A) Anaphylactic shock
B) Cardiogenic shock
C) Hypovolemic shock
D) Neurogenic shock
Rationale: Hypovolemic shock is caused by massive blood or fluid loss, which prevents
the heart from pumping enough blood to vital organs.
17. What type of grid error happens when a focused grid is tilted relative to the central ray
of the x-ray beam?
A) Off-center grid error
B) Off-distance grid error
C) Off-level grid error
D) Upside-down grid error
Rationale: An off-level grid error occurs if the grid is tilted or if the tube is angled across
the grid lines, causing a uniform loss of exposure.
18. What basic positioning step is required to demonstrate the olecranon process in profile?
A) AP projection of the elbow
B) Medial oblique projection of the elbow
C) Lateral oblique projection of the elbow
D) True lateral projection of the elbow
Rationale: Flexing the elbow 90 degrees and placing it in a true lateral position projects
the olecranon process directly into profile posteriorly.
19. What type of cells are considered the least radiosensitive according to the law of
Bergonie and Tribondeau?
A) Stem cells
B) Nerve cells
C) Erythroblasts
D) Lymphocytes
Rationale: Highly specialized, mature cells that do not undergo regular cellular division
(like nerve and muscle cells) are highly radioresistant.
20. What is the function of the autotransformer inside a standard x-ray machine circuit?
A) Converts alternating current to direct current
B) Allows for the selection of the primary voltage level (kVp)
C) Heats up the filament wire to boil off electrons
D) Protects the circuit from electrical power surges
Rationale: The autotransformer operates on self-induction and lets the technologist step
up or step down the input voltage before it goes to the main step-up transformer.
21. Which projection of the skull will project the petrous ridges into the lower one-third of the
orbits?
A) AP projection (0-degree angle)
B) PA axial projection (Caldwell method)
C) Parietoacanthial projection (Waters method)
D) Submentovertex projection (SMV)
Rationale: A 15-degree caudad angle on a PA skull projection (Caldwell view) pushes
the dense petrous ridges down into the lower third of the eye orbits.
22. What basic processing tool adjusts the window level of a digital image during post-
processing review?
