ASRT SEAL EXAM NEWEST 2025/2026 ACTUAL EXAM COMPLETE 170 QUESTIONS AND
CORRECT DETAILED ANSWERS/NEWEST UPDATE!!!
Question 1
Mycosis fungoides is the most common form of:
A) Non-Hodgkin Lymphoma of the bone
B) Cutaneous T-cell lymphoma
C) Squamous cell carcinoma of the skin
D) Acute Myeloid Leukemia
E) Kaposi Sarcoma
Correct Answer: B) Cutaneous T-cell lymphoma
Rationale: Mycosis fungoides is a mature T-cell lymphoma that primarily affects the skin. It
often presents as itchy, scaly patches or plaques and can eventually progress to involve the
lymph nodes and internal organs.
Question 2
Radiolucent contrast agents, such as air or carbon dioxide, have which of the following effects on
a radiograph?
A) They appear bright white
B) They increase the atomic number of the organ
C) They appear dark/black on radiographs
D) They completely block x-ray transmission
E) They are only used for intravenous injections
Correct Answer: C) They appear dark/black on radiographs
Rationale: Radiolucent (negative) contrast agents have low atomic numbers and low density,
allowing x-rays to pass through easily. This results in dark areas on the image, providing
contrast against denser surrounding tissues.
Question 3
Nosocomial infections are specifically defined as those that are:
A) Contracted in a public place
B) Spread through contaminated food
C) Acquired while the patient is in the hospital
D) Resulting from a genetic predisposition
E) Only spread via needle sticks
Correct Answer: C) Acquired while the patient is in the hospital
Rationale: Also known as Healthcare-Associated Infections (HAIs), nosocomial infections
are those that a patient develops while receiving treatment in a healthcare facility that were
not present at the time of admission.
Question 4
The anatomical plane which divides the body into anterior (front) and posterior (back) portions is
the:
, 2
A) Sagittal plane
B) Transverse plane
C) Coronal plane
D) Horizontal plane
E) Axial plane
Correct Answer: C) Coronal plane
Rationale: The coronal (or frontal) plane runs vertically and divides the body into front and
back sections. The sagittal plane divides left from right, and the transverse/axial plane
divides top from bottom.
Question 5
What is the Tolerance Dose for 5% risk at 5 years (TD 5/5) when irradiating one-third (1/3) of
the brain?
A) 30 Gy
B) 45 Gy
C) 50 Gy
D) 60 Gy
E) 100 Gy
Correct Answer: D) 60 Gy
Rationale: The whole brain tolerance is lower (approx. 45 Gy), but when only a partial
volume (1/3) is treated, the tolerance dose increases to approximately 60 Gy before the risk
of necrosis exceeds 5%.
Question 6
Radiation-induced myelopathy is a serious late effect resulting from which part of the body
receiving more than its tolerance dose?
A) Brainstem
B) Spinal cord
C) Esophagus
D) Brachial plexus
E) Cauda equina
Correct Answer: B) Spinal cord
Rationale: Myelopathy refers to damage to the spinal cord. In radiation therapy, exceeding
the spinal cord tolerance (usually 45–50 Gy) can lead to irreversible necrosis and paralysis.
Question 7
What is the Tolerance Dose for 5% risk at 5 years (TD 5/5) for the whole liver?
A) 10 Gy
B) 20 Gy
C) 30 Gy
D) 40 Gy
, 3
E) 50 Gy
Correct Answer: C) 30 Gy
Rationale: The liver is a radiosensitive organ. When the whole liver is irradiated, the TD 5/5
is approximately 30 Gy. Exceeding this increases the risk of radiation-induced liver disease
(RILD).
Question 8
The spinal cord is about 25 cm shorter than the vertebral column, usually ending near the level
of:
A) T10-T11
B) T12-L1
C) L1-L2
D) L4-L5
E) S1-S2
Correct Answer: C) L1-L2
Rationale: In adults, the conus medullaris (the tapered end of the spinal cord) typically
terminates at the level of the first or second lumbar vertebra.
Question 9
Which of the following is an external landmark often used for positioning and alignment when
setting up whole brain treatments?
A) Mastoid process
B) External acoustic meatus (EAM)
C) Mental protuberance
D) Thyroid cartilage
E) Hyoid bone
Correct Answer: B) External acoustic meatus (EAM)
Rationale: The EAM is a stable bony landmark of the ear that is frequently used in head
and neck setups and whole brain fields to ensure proper tilt and centering of the cranium.
Question 10
To determine the depth of the spinal cord, a 7 cm ring is placed on the patient's skin. On the
radiograph, the ring measures 8.2 cm. What is the magnification factor?
A) 0.85
B) 1.17
C) 1.25
D) 1.42
E) 1.57
Correct Answer: B) 1.17
Rationale: Magnification Factor = Image Size / Object Size.
CORRECT DETAILED ANSWERS/NEWEST UPDATE!!!
Question 1
Mycosis fungoides is the most common form of:
A) Non-Hodgkin Lymphoma of the bone
B) Cutaneous T-cell lymphoma
C) Squamous cell carcinoma of the skin
D) Acute Myeloid Leukemia
E) Kaposi Sarcoma
Correct Answer: B) Cutaneous T-cell lymphoma
Rationale: Mycosis fungoides is a mature T-cell lymphoma that primarily affects the skin. It
often presents as itchy, scaly patches or plaques and can eventually progress to involve the
lymph nodes and internal organs.
Question 2
Radiolucent contrast agents, such as air or carbon dioxide, have which of the following effects on
a radiograph?
A) They appear bright white
B) They increase the atomic number of the organ
C) They appear dark/black on radiographs
D) They completely block x-ray transmission
E) They are only used for intravenous injections
Correct Answer: C) They appear dark/black on radiographs
Rationale: Radiolucent (negative) contrast agents have low atomic numbers and low density,
allowing x-rays to pass through easily. This results in dark areas on the image, providing
contrast against denser surrounding tissues.
Question 3
Nosocomial infections are specifically defined as those that are:
A) Contracted in a public place
B) Spread through contaminated food
C) Acquired while the patient is in the hospital
D) Resulting from a genetic predisposition
E) Only spread via needle sticks
Correct Answer: C) Acquired while the patient is in the hospital
Rationale: Also known as Healthcare-Associated Infections (HAIs), nosocomial infections
are those that a patient develops while receiving treatment in a healthcare facility that were
not present at the time of admission.
Question 4
The anatomical plane which divides the body into anterior (front) and posterior (back) portions is
the:
, 2
A) Sagittal plane
B) Transverse plane
C) Coronal plane
D) Horizontal plane
E) Axial plane
Correct Answer: C) Coronal plane
Rationale: The coronal (or frontal) plane runs vertically and divides the body into front and
back sections. The sagittal plane divides left from right, and the transverse/axial plane
divides top from bottom.
Question 5
What is the Tolerance Dose for 5% risk at 5 years (TD 5/5) when irradiating one-third (1/3) of
the brain?
A) 30 Gy
B) 45 Gy
C) 50 Gy
D) 60 Gy
E) 100 Gy
Correct Answer: D) 60 Gy
Rationale: The whole brain tolerance is lower (approx. 45 Gy), but when only a partial
volume (1/3) is treated, the tolerance dose increases to approximately 60 Gy before the risk
of necrosis exceeds 5%.
Question 6
Radiation-induced myelopathy is a serious late effect resulting from which part of the body
receiving more than its tolerance dose?
A) Brainstem
B) Spinal cord
C) Esophagus
D) Brachial plexus
E) Cauda equina
Correct Answer: B) Spinal cord
Rationale: Myelopathy refers to damage to the spinal cord. In radiation therapy, exceeding
the spinal cord tolerance (usually 45–50 Gy) can lead to irreversible necrosis and paralysis.
Question 7
What is the Tolerance Dose for 5% risk at 5 years (TD 5/5) for the whole liver?
A) 10 Gy
B) 20 Gy
C) 30 Gy
D) 40 Gy
, 3
E) 50 Gy
Correct Answer: C) 30 Gy
Rationale: The liver is a radiosensitive organ. When the whole liver is irradiated, the TD 5/5
is approximately 30 Gy. Exceeding this increases the risk of radiation-induced liver disease
(RILD).
Question 8
The spinal cord is about 25 cm shorter than the vertebral column, usually ending near the level
of:
A) T10-T11
B) T12-L1
C) L1-L2
D) L4-L5
E) S1-S2
Correct Answer: C) L1-L2
Rationale: In adults, the conus medullaris (the tapered end of the spinal cord) typically
terminates at the level of the first or second lumbar vertebra.
Question 9
Which of the following is an external landmark often used for positioning and alignment when
setting up whole brain treatments?
A) Mastoid process
B) External acoustic meatus (EAM)
C) Mental protuberance
D) Thyroid cartilage
E) Hyoid bone
Correct Answer: B) External acoustic meatus (EAM)
Rationale: The EAM is a stable bony landmark of the ear that is frequently used in head
and neck setups and whole brain fields to ensure proper tilt and centering of the cranium.
Question 10
To determine the depth of the spinal cord, a 7 cm ring is placed on the patient's skin. On the
radiograph, the ring measures 8.2 cm. What is the magnification factor?
A) 0.85
B) 1.17
C) 1.25
D) 1.42
E) 1.57
Correct Answer: B) 1.17
Rationale: Magnification Factor = Image Size / Object Size.
