GXMO Quality Control and Maintenance Flashcards

Automatic exposure control (AEC) devices should be tested regularly. A common QC test for AEC verifies:

Answer: Consistency of mAs output across different kVp settings

AEC QC tests confirm that the system delivers consistent mAs (and therefore consistent receptor exposure) across a range of kVp values and patient thicknesses.

Artifacts caused by dirt or debris on a CR (computed radiography) imaging plate most commonly appear as:

Answer: White (unexposed) or black dots and lines on the image

Foreign material on a CR plate blocks or scatters the laser during readout, creating white (or occasionally dark) artifacts on the processed image.

The base-plus-fog (B+F) level of radiographic film processed without exposure should be:

Answer: 0.18 or less

A B+F density of 0.18 or less indicates that the film base and chemical fog are within acceptable limits, ensuring adequate image contrast.

Which component of a digital radiography system converts X-ray photons directly into an electrical signal without an intermediate step?

Answer: Direct DR flat panel detector (amorphous selenium)

Direct DR detectors use amorphous selenium to convert X-rays directly to electrical charge, while indirect detectors use a scintillator to first convert X-rays to light.

Repeat analysis in a quality control program is performed to:

Answer: Identify common causes of repeat exposures and reduce patient dose

Repeat analysis tracks the frequency and reasons for repeated exposures, allowing targeted corrective action to reduce unnecessary patient radiation dose.

The speed of an X-ray film-screen system refers to:

Answer: Its sensitivity to radiation (ability to produce diagnostic density with less exposure)

Screen-film speed (e.g., 100, 200, 400) indicates the system's sensitivity; higher speed requires less radiation to achieve the same image density, reducing patient dose.