ARRT Final Competency Certification Study Guide
Exam Questions with Certified for Accuracy Answers
2025/2026
The X-ray beam used in CT is? - correct answer Polychromatic (beam has
photons of varying energies).
What are the benefits of filtering x-ray beams? - correct answer 1)
Improves image quality (filters low energy photons that cause artifacts).
2) Reduces dose to the patient.
Volume averaging (Partial volume effect) - correct answer Different tissue
attenuations are averaged to produce one less accurate pixel reading
(thinner slices = decreased volume averaging).
How are x-rays created? - correct answer When a substance is
bombarded by fast moving electrons.
Ma (milliamperes) - correct answer Controls the quantity of elections.
Kvp (kilovolt peak) - correct answer Intensity of the x-ray beam.
Dissipation - correct answer Ability of the tube to rid itself of heat.
DAS - correct answer Data Acquisition System - measures the amount of
photons that strike the detector, converts the info to a digital signal and
sends the signal to the computer.
, CPU - correct answer Central Processing Unit
Pixel - correct answer Two-dimensional square of data.
How many CT numbers are assigned to each pixel? - correct answer One.
Raw Data is also known as? - correct answer Scan Data.
Typical aperature size? - correct answer 70-90cm.
Slip rings - correct answer Brush-like apparatus that allows for the gantry
to rotate continuously, allowing for helical scanning.
Generators - correct answer Located in the gantry, produce high voltages
that are passed onto the x-ray tube, measured in kilowatts (kw).
Reducing scatter radiation does what? - correct answer 1. Improves
contrast resolution.
2. Decreases patient dose.
Optimal characteristics for of a detector? - correct answer 1. High detector
efficiency.
2. Low, or no afterglow.
3. High scatter suppression.
4. High stability.
Exam Questions with Certified for Accuracy Answers
2025/2026
The X-ray beam used in CT is? - correct answer Polychromatic (beam has
photons of varying energies).
What are the benefits of filtering x-ray beams? - correct answer 1)
Improves image quality (filters low energy photons that cause artifacts).
2) Reduces dose to the patient.
Volume averaging (Partial volume effect) - correct answer Different tissue
attenuations are averaged to produce one less accurate pixel reading
(thinner slices = decreased volume averaging).
How are x-rays created? - correct answer When a substance is
bombarded by fast moving electrons.
Ma (milliamperes) - correct answer Controls the quantity of elections.
Kvp (kilovolt peak) - correct answer Intensity of the x-ray beam.
Dissipation - correct answer Ability of the tube to rid itself of heat.
DAS - correct answer Data Acquisition System - measures the amount of
photons that strike the detector, converts the info to a digital signal and
sends the signal to the computer.
, CPU - correct answer Central Processing Unit
Pixel - correct answer Two-dimensional square of data.
How many CT numbers are assigned to each pixel? - correct answer One.
Raw Data is also known as? - correct answer Scan Data.
Typical aperature size? - correct answer 70-90cm.
Slip rings - correct answer Brush-like apparatus that allows for the gantry
to rotate continuously, allowing for helical scanning.
Generators - correct answer Located in the gantry, produce high voltages
that are passed onto the x-ray tube, measured in kilowatts (kw).
Reducing scatter radiation does what? - correct answer 1. Improves
contrast resolution.
2. Decreases patient dose.
Optimal characteristics for of a detector? - correct answer 1. High detector
efficiency.
2. Low, or no afterglow.
3. High scatter suppression.
4. High stability.
