RADIOGRAPHIC IMAGE ANALYSIS 6TH
EDITION MARTENSEN TEST BANK – 200 REAL
EXAM Q&AS WITH RATIONALES
Question 1
,When evaluating a digital radiographic image for structural accuracy, which factor is the
primary indicator of proper receptor exposure?
A) Visual brightness on the display monitor
B) The Exposure Index (EI) number
C) Selection of the look-up table (LUT)
D) Post-processing window leveling
Verified Answer: B) The Exposure Index (EI) number
Explanation: In digital radiography, visual brightness on the monitor is automatically
adjusted by computer algorithms (rescaling) and does not accurately reflect actual receptor
exposure. The Exposure Index (EI) value is the only reliable numerical metric to verify
that the receptor received the correct amount of radiation, ensuring an optimal signal-to-
noise ratio without overexposing the patient.
Question 2
An anteroposterior (AP) chest radiograph reveals that the medial clavicular ends are not
equidistant from the vertebral column. The right clavicular end is projected closer to the spine
than the left. What positioning error has occurred?
A) The patient was rotated into a Left Anterior Oblique (LAO) position.
B) The patient was rotated into a Right Posterior Oblique (RPO) position.
C) The patient was rotated toward the left side (Left Posterior Oblique/LPO).
D) The patient was rotated toward the right side (Right Posterior Oblique/RPO) or left side
(LAO).
Verified Answer: C) The patient was rotated toward the left side (Left Posterior
Oblique/LPO).
Explanation: On an AP thoracic projection (such as an AP chest), rotation can be
determined by evaluating the sternoclavicular (SC) joints. The side toward which the
patient is rotated moves the spine away from that clavicle, making the opposite clavicle
appear closer to the vertebral column. If the right clavicle is closer to the spine, the spine
has shifted rightward relative to the clavicles, meaning the left side of the chest was rotated
closer to the image receptor (LPO or RAO rotation).
Question 3
Which technical factor primarily controls the scale of contrast in digital radiographic systems
prior to computer processing?
,A) Milliampere-seconds (mAs)
B) Kilovoltage peak (kVp)
C) Look-up Table (LUT) application
D) Source-to-Image Distance (SID)
Verified Answer: C) Look-up Table (LUT) application
Explanation: While kVp influences differential absorption in the patient, the final
displayed contrast scale in digital imaging is primarily determined by the Look-up Table
(LUT) applied during image processing. The LUT maps raw data values to specific
grayscale values to match the anatomical part being imaged.
Question 4
A lateral knee radiograph demonstrates the adductor tubercle on the posterior aspect of the
medial femoral condyle. The deep surfaces of the femoral condyles are not superimposed.
How must the technician adjust the patient's position to correct this error?
A) Cephalad angulation must be increased.
B) The leg was externally rotated; it must be rotated internally.
C) The leg was internally rotated; it must be rotated externally.
D) The central ray must be directed perpendicular to the patella.
Verified Answer: B) The leg was externally rotated; it must be rotated internally.
Explanation: The adductor tubercle is located on the posteromedial aspect of the medial
femoral condyle. On a true lateral knee radiograph, the condyles should be superimposed.
If the adductor tubercle is visible posteriorly, it indicates the medial condyle is projected
behind the lateral condyle, which is caused by external rotation of the knee. Internal
rotation is required to bring the condyles into superimposition.
Question 5
What type of artifact appears as a distinct series of parallel lines across a digital radiograph
when an stationary grid's frequency matches the laser scanning frequency of a CR reader?
A) Quantum mottle
B) Moire pattern
C) Ghost image
D) Halo effect
Verified Answer: B) Moire pattern
Explanation: The Moire artifact (or grid alias artifact) occurs in computed radiography
, (CR) when a stationary grid is used and its grid line frequency closely matches the spatial
sampling frequency of the CR reader's laser scanner. This creates an interference pattern
resembling wavy lines.
Question 6
An AP projection of the pelvis demonstrates the femoral necks foreshortened, with the lesser
trochanters prominent and visible in profile medially. What positioning correction is
necessary?
A) Internally rotate the patient's lower extremities 15 to 20 degrees.
B) Externally rotate the patient's lower extremities 15 to 20 degrees.
C) Abduct the patient's lower extremities 45 degrees.
D) Decrease the cephalad angulation of the central ray.
Verified Answer: A) Internally rotate the patient's lower extremities 15 to 20 degrees.
Explanation: To accurately evaluate the pelvic girdle and femoral necks without distortion
on an AP projection, the lower limbs must be rotated internally 15 to 20 degrees. This
rotation places the femoral necks parallel to the image receptor, profiles the greater
trochanters laterally, and obscures or minimizes the visibility of the lesser trochanters.
Prominent lesser trochanters indicate external rotation.
Question 7
If a digital radiograph exhibits a high degree of quantum mottle, what does this indicate
regarding the technical factors used?
A) The kVp was excessively high, causing scatter fog.
B) The mAs was insufficient, resulting in low photon flux to the receptor.
C) The matrix size selected was too small for the field of view.
D) An incorrect look-up table was applied to the raw data.
Verified Answer: B) The mAs was insufficient, resulting in low photon flux to the receptor.
Explanation: Quantum mottle is a form of radiographic noise that occurs when an
insufficient number of X-ray photons reach the image receptor (low photon flux). This is
typically caused by selecting a mAs value that is too low, creating a grainy appearance that
degrades spatial resolution.
Question 8
EDITION MARTENSEN TEST BANK – 200 REAL
EXAM Q&AS WITH RATIONALES
Question 1
,When evaluating a digital radiographic image for structural accuracy, which factor is the
primary indicator of proper receptor exposure?
A) Visual brightness on the display monitor
B) The Exposure Index (EI) number
C) Selection of the look-up table (LUT)
D) Post-processing window leveling
Verified Answer: B) The Exposure Index (EI) number
Explanation: In digital radiography, visual brightness on the monitor is automatically
adjusted by computer algorithms (rescaling) and does not accurately reflect actual receptor
exposure. The Exposure Index (EI) value is the only reliable numerical metric to verify
that the receptor received the correct amount of radiation, ensuring an optimal signal-to-
noise ratio without overexposing the patient.
Question 2
An anteroposterior (AP) chest radiograph reveals that the medial clavicular ends are not
equidistant from the vertebral column. The right clavicular end is projected closer to the spine
than the left. What positioning error has occurred?
A) The patient was rotated into a Left Anterior Oblique (LAO) position.
B) The patient was rotated into a Right Posterior Oblique (RPO) position.
C) The patient was rotated toward the left side (Left Posterior Oblique/LPO).
D) The patient was rotated toward the right side (Right Posterior Oblique/RPO) or left side
(LAO).
Verified Answer: C) The patient was rotated toward the left side (Left Posterior
Oblique/LPO).
Explanation: On an AP thoracic projection (such as an AP chest), rotation can be
determined by evaluating the sternoclavicular (SC) joints. The side toward which the
patient is rotated moves the spine away from that clavicle, making the opposite clavicle
appear closer to the vertebral column. If the right clavicle is closer to the spine, the spine
has shifted rightward relative to the clavicles, meaning the left side of the chest was rotated
closer to the image receptor (LPO or RAO rotation).
Question 3
Which technical factor primarily controls the scale of contrast in digital radiographic systems
prior to computer processing?
,A) Milliampere-seconds (mAs)
B) Kilovoltage peak (kVp)
C) Look-up Table (LUT) application
D) Source-to-Image Distance (SID)
Verified Answer: C) Look-up Table (LUT) application
Explanation: While kVp influences differential absorption in the patient, the final
displayed contrast scale in digital imaging is primarily determined by the Look-up Table
(LUT) applied during image processing. The LUT maps raw data values to specific
grayscale values to match the anatomical part being imaged.
Question 4
A lateral knee radiograph demonstrates the adductor tubercle on the posterior aspect of the
medial femoral condyle. The deep surfaces of the femoral condyles are not superimposed.
How must the technician adjust the patient's position to correct this error?
A) Cephalad angulation must be increased.
B) The leg was externally rotated; it must be rotated internally.
C) The leg was internally rotated; it must be rotated externally.
D) The central ray must be directed perpendicular to the patella.
Verified Answer: B) The leg was externally rotated; it must be rotated internally.
Explanation: The adductor tubercle is located on the posteromedial aspect of the medial
femoral condyle. On a true lateral knee radiograph, the condyles should be superimposed.
If the adductor tubercle is visible posteriorly, it indicates the medial condyle is projected
behind the lateral condyle, which is caused by external rotation of the knee. Internal
rotation is required to bring the condyles into superimposition.
Question 5
What type of artifact appears as a distinct series of parallel lines across a digital radiograph
when an stationary grid's frequency matches the laser scanning frequency of a CR reader?
A) Quantum mottle
B) Moire pattern
C) Ghost image
D) Halo effect
Verified Answer: B) Moire pattern
Explanation: The Moire artifact (or grid alias artifact) occurs in computed radiography
, (CR) when a stationary grid is used and its grid line frequency closely matches the spatial
sampling frequency of the CR reader's laser scanner. This creates an interference pattern
resembling wavy lines.
Question 6
An AP projection of the pelvis demonstrates the femoral necks foreshortened, with the lesser
trochanters prominent and visible in profile medially. What positioning correction is
necessary?
A) Internally rotate the patient's lower extremities 15 to 20 degrees.
B) Externally rotate the patient's lower extremities 15 to 20 degrees.
C) Abduct the patient's lower extremities 45 degrees.
D) Decrease the cephalad angulation of the central ray.
Verified Answer: A) Internally rotate the patient's lower extremities 15 to 20 degrees.
Explanation: To accurately evaluate the pelvic girdle and femoral necks without distortion
on an AP projection, the lower limbs must be rotated internally 15 to 20 degrees. This
rotation places the femoral necks parallel to the image receptor, profiles the greater
trochanters laterally, and obscures or minimizes the visibility of the lesser trochanters.
Prominent lesser trochanters indicate external rotation.
Question 7
If a digital radiograph exhibits a high degree of quantum mottle, what does this indicate
regarding the technical factors used?
A) The kVp was excessively high, causing scatter fog.
B) The mAs was insufficient, resulting in low photon flux to the receptor.
C) The matrix size selected was too small for the field of view.
D) An incorrect look-up table was applied to the raw data.
Verified Answer: B) The mAs was insufficient, resulting in low photon flux to the receptor.
Explanation: Quantum mottle is a form of radiographic noise that occurs when an
insufficient number of X-ray photons reach the image receptor (low photon flux). This is
typically caused by selecting a mAs value that is too low, creating a grainy appearance that
degrades spatial resolution.
Question 8
