QC IR and Display Monitor

A detector is exposed twice using the same radiation exposure, but it produces noticeably different responses. Which QC area is being tested?

Detector calibration

What is the main purpose of detector calibration?

To make sure the detector gives a correct and consistent response to the same radiation exposure.

How is detector calibration different from plate uniformity?

Calibration checks consistent/correct detector response; uniformity checks whether the entire receptor responds evenly across its surface.

A CR plate is exposed, erased, and then read again. What QC test is being performed?

Erasure thoroughness.

What indicates failure of a CR erasure-thoroughness test?

A residual or ghost image from the previous exposure remains visible.

What is the goal of CR erasure thoroughness?

To verify that the previous latent image was completely removed before the plate is reused.

A uniform exposure is made across an image receptor, but one side appears darker than the other. Which QC test failed?

Plate uniformity.

What does plate uniformity evaluate?

Whether the entire image receptor responds evenly to the same uniform radiation exposure.

What finding would indicate poor plate uniformity?

Uneven brightness, streaks, artifacts, or different receptor response across the image.

A receptor is tested with a line-pair phantom. What characteristic is being evaluated?

Spatial resolution.

What does a higher lp/mm value indicate?

Better spatial resolution; the system can resolve finer detail.

What unit is commonly used to describe receptor spatial resolution?

Line pairs per millimeter, lp/mm.

A detector resolves more line pairs on a test pattern than another detector. Which detector has better spatial resolution?

The detector that resolves more line pairs per millimeter.

What is the simplest way to distinguish IR calibration, uniformity, erasure, and spatial-resolution QC?

Calibration = same exposure, same response; Uniformity = even response across receptor; Erasure = old image gone; Spatial resolution = fine detail/line pairs.

A diagnostic monitor displays the same image differently from another properly configured monitor. Which QC area should be checked?

Monitor calibration.

What is the main goal of monitor calibration?

To make sure grayscale and brightness are displayed consistently and accurately.

What does DICOM GSDF stand for in display QC?

Grayscale Standard Display Function.

What is DICOM GSDF used for?

To standardize how grayscale differences are displayed on diagnostic monitors.

Which DICOM standard is associated with monitor grayscale calibration?

DICOM PS 3.14.

A monitor can no longer clearly distinguish very similar shades of gray. Which display characteristic is most affected?

Display contrast.

What does display contrast evaluate?

The monitor's ability to distinguish differences between light and dark or similar shades of gray.

What does monitor spatial resolution evaluate?

The monitor's ability to display fine detail sharply.

A test pattern appears stretched or warped on the monitor. Which display QC problem is present?

Distortion.

What does luminance mean in monitor QC?

The amount of light or brightness produced by the monitor.

What is the difference between luminance and contrast?

Luminance = monitor brightness/light output; Contrast = ability to distinguish differences between gray levels.

Which monitor QC test asks, “Is the monitor bright enough and producing the correct amount of light?”

Luminance evaluation.

Which monitor QC test asks, “Can I distinguish subtle shades of gray?”

Display contrast evaluation.

Which monitor QC test asks, “Are shapes and lines displayed without warping?”

Distortion evaluation.

Which monitor QC test asks, “Can I see fine detail?”

Spatial-resolution evaluation.

What is the simplest distinction between image receptor QC and display QC?

IR QC asks whether the detector records the image correctly; display QC asks whether the monitor shows the image correctly.