[HAADMI] HAAD MI DOH Licensureination
for Medical Imaging Certification Exam
Preparation
**Question 1.** What is the primary purpose of the ALARA principle in radiology?
A) To increase image contrast
B) To minimize radiation exposure to as low as reasonably achievable
C) To maximize patient throughput
D) To standardize imaging protocols
Answer: B
Explanation: ALARA (As Low As Reasonably Achievable) directs professionals to keep radiation
doses as low as possible while obtaining diagnostic quality images.
**Question 2.** Which of the following is a deterministic effect of radiation?
A) Leukemia
B) Cataract formation
C) Skin erythema
D) Genetic mutations
Answer: C
Explanation: Deterministic effects have a threshold dose; skin erythema appears only after a
certain dose is exceeded, unlike stochastic effects which have no threshold.
**Question 3.** The most radiosensitive tissue in the adult body is:
A) Muscle
B) Bone marrow
C) Liver
D) Lung
Answer: B
, [HAADMI] HAAD MI DOH Licensureination
for Medical Imaging Certification Exam
Preparation
Explanation: Bone marrow contains rapidly dividing cells, making it highly susceptible to
radiation-induced damage.
**Question 4.** Which dosimeter type uses thermoluminescent material to measure radiation
dose?
A) OSL dosimeter
B) TLD (Thermoluminescent Dosimeter)
C) Film badge
D) Electronic personal dosimeter
Answer: B
Explanation: TLDs trap electrons in a crystal lattice and release light when heated, providing a
dose measurement.
**Question 5.** The annual dose limit for the lens of the eye for occupational workers
according to ICRP recommendations is:
A) 5 mSv
B) 10 mSv
C) 20 mSv
D) 50 mSv
Answer: C
Explanation: The ICRP recommends a limit of 20 mSv per year averaged over five years for the
eye lens.
**Question 6.** Which of the following shielding devices is most effective for protecting the
thyroid during a chest X‑ray?
, [HAADMI] HAAD MI DOH Licensureination
for Medical Imaging Certification Exam
Preparation
A) Lead apron
B) Thyroid collar
C) Gonadal shield
D) Mobile lead wall
Answer: B
Explanation: A thyroid collar specifically covers the thyroid gland, reducing its exposure during
head‑to‑chest imaging.
**Question 7.** When optimizing patient dose, decreasing the kVp will:
A) Increase photon energy and reduce patient dose
B) Decrease image contrast and increase patient dose
C) Increase image contrast but increase patient dose
D) Decrease patient dose but increase image noise
Answer: D
Explanation: Lower kVp reduces photon energy, leading to higher attenuation and potentially
higher dose; however, it also reduces patient dose per photon but may increase noise, requiring
higher mAs.
**Question 8.** In an X‑ray tube, the component that emits electrons is the:
A) Anode
B) Cathode
C) Filament
D) Grid
Answer: B
, [HAADMI] HAAD MI DOH Licensureination
for Medical Imaging Certification Exam
Preparation
Explanation: The cathode contains a heated filament that releases electrons, which are then
accelerated toward the anode.
**Question 9.** The primary cooling method for high‑heat‑load X‑ray tubes is:
A) Forced air cooling
B) Water cooling
C) Oil immersion
D) Radiative cooling
Answer: B
Explanation: Water‑cooled tubes dissipate large amounts of heat efficiently, maintaining tube
temperature during high‑dose procedures.
**Question 10.** Direct Radiography (DR) detectors differ from Computed Radiography (CR)
plates primarily because DR uses:
A) Photostimulable phosphor plates
B) Scintillator‑coupled flat‑panel detectors
C) Film‑screen technology
D) Analog image intensifiers
Answer: B
Explanation: DR employs flat‑panel detectors with scintillators (e.g., CsI) directly converting
X‑rays to electronic signals, eliminating the need for CR plates.
**Question 11.** Which phenomenon is responsible for the “grid line” artifact seen on
fluoroscopic images?
A) Aliasing
for Medical Imaging Certification Exam
Preparation
**Question 1.** What is the primary purpose of the ALARA principle in radiology?
A) To increase image contrast
B) To minimize radiation exposure to as low as reasonably achievable
C) To maximize patient throughput
D) To standardize imaging protocols
Answer: B
Explanation: ALARA (As Low As Reasonably Achievable) directs professionals to keep radiation
doses as low as possible while obtaining diagnostic quality images.
**Question 2.** Which of the following is a deterministic effect of radiation?
A) Leukemia
B) Cataract formation
C) Skin erythema
D) Genetic mutations
Answer: C
Explanation: Deterministic effects have a threshold dose; skin erythema appears only after a
certain dose is exceeded, unlike stochastic effects which have no threshold.
**Question 3.** The most radiosensitive tissue in the adult body is:
A) Muscle
B) Bone marrow
C) Liver
D) Lung
Answer: B
, [HAADMI] HAAD MI DOH Licensureination
for Medical Imaging Certification Exam
Preparation
Explanation: Bone marrow contains rapidly dividing cells, making it highly susceptible to
radiation-induced damage.
**Question 4.** Which dosimeter type uses thermoluminescent material to measure radiation
dose?
A) OSL dosimeter
B) TLD (Thermoluminescent Dosimeter)
C) Film badge
D) Electronic personal dosimeter
Answer: B
Explanation: TLDs trap electrons in a crystal lattice and release light when heated, providing a
dose measurement.
**Question 5.** The annual dose limit for the lens of the eye for occupational workers
according to ICRP recommendations is:
A) 5 mSv
B) 10 mSv
C) 20 mSv
D) 50 mSv
Answer: C
Explanation: The ICRP recommends a limit of 20 mSv per year averaged over five years for the
eye lens.
**Question 6.** Which of the following shielding devices is most effective for protecting the
thyroid during a chest X‑ray?
, [HAADMI] HAAD MI DOH Licensureination
for Medical Imaging Certification Exam
Preparation
A) Lead apron
B) Thyroid collar
C) Gonadal shield
D) Mobile lead wall
Answer: B
Explanation: A thyroid collar specifically covers the thyroid gland, reducing its exposure during
head‑to‑chest imaging.
**Question 7.** When optimizing patient dose, decreasing the kVp will:
A) Increase photon energy and reduce patient dose
B) Decrease image contrast and increase patient dose
C) Increase image contrast but increase patient dose
D) Decrease patient dose but increase image noise
Answer: D
Explanation: Lower kVp reduces photon energy, leading to higher attenuation and potentially
higher dose; however, it also reduces patient dose per photon but may increase noise, requiring
higher mAs.
**Question 8.** In an X‑ray tube, the component that emits electrons is the:
A) Anode
B) Cathode
C) Filament
D) Grid
Answer: B
, [HAADMI] HAAD MI DOH Licensureination
for Medical Imaging Certification Exam
Preparation
Explanation: The cathode contains a heated filament that releases electrons, which are then
accelerated toward the anode.
**Question 9.** The primary cooling method for high‑heat‑load X‑ray tubes is:
A) Forced air cooling
B) Water cooling
C) Oil immersion
D) Radiative cooling
Answer: B
Explanation: Water‑cooled tubes dissipate large amounts of heat efficiently, maintaining tube
temperature during high‑dose procedures.
**Question 10.** Direct Radiography (DR) detectors differ from Computed Radiography (CR)
plates primarily because DR uses:
A) Photostimulable phosphor plates
B) Scintillator‑coupled flat‑panel detectors
C) Film‑screen technology
D) Analog image intensifiers
Answer: B
Explanation: DR employs flat‑panel detectors with scintillators (e.g., CsI) directly converting
X‑rays to electronic signals, eliminating the need for CR plates.
**Question 11.** Which phenomenon is responsible for the “grid line” artifact seen on
fluoroscopic images?
A) Aliasing
