X-Ray Certification Equipment Operation and Maintenance 5

Question 1

What is the purpose of the filament circuit in an X-ray tube?

Accepted Answer

It heats the filament to produce electrons by thermionic emission

Answer

The filament circuit supplies low-voltage current to heat the tungsten filament, causing thermionic emission — the release of electrons needed for X-ray production.

Question 2

Which grid ratio is most appropriate for high kVp (above 100 kVp) imaging to effectively remove scatter?

Accepted Answer

12:1 or 16:1

Answer

High-ratio grids (12:1 or 16:1) are needed for high-kVp techniques because higher-energy scatter photons travel at smaller angles and require taller grid strips to be absorbed.

Question 3

A flat-panel digital detector must be recalibrated with offset and gain corrections primarily for what reason?

Accepted Answer

To correct for individual pixel variations and dead pixels to maintain image uniformity

Answer

Offset (dark field) and gain (flood field) calibration correct for individual pixel variations, defective pixels, and non-uniformities in the detector to ensure consistent, artifact-free images.

Question 4

What is the primary advantage of using a rotating anode over a stationary anode in diagnostic X-ray tubes?

Accepted Answer

It allows heat to be distributed over a larger anode surface area, permitting higher techniques

Answer

Rotation distributes the heat load over a much larger surface (the entire anode track) rather than a single stationary focal spot, dramatically increasing the tube's heat loading capacity.

Question 5

Grid cutoff artifacts appear on a radiograph as decreased density in certain areas. Which of the following causes lateral grid cutoff?

Accepted Answer

Off-centering the X-ray beam laterally from the grid center

Answer

Lateral decentering (off-centering the tube from the grid's focal range) causes the angled grid strips to absorb the primary beam on one side, producing decreased density in that area.

X-Ray Certification Practice Test

X-Ray Certification Practice Test

X-Ray Certification Equipment Operation and Maintenance 5