DRC Quality Control & Process Improvement 2 — Questions and Answers
Question 1: Which sensitometric step on a film should be used to monitor the speed point in a quality control program?
- Step closest to the base plus fog density
- Step with a density closest to 1.0 above base plus fog (Correct answer)
- Step with the highest optical density on the strip
- Step at the middle of the gray scale
Correct answer: Step with a density closest to 1.0 above base plus fog
The speed point is identified as the step density closest to 1.0 above base plus fog, representing mid-range film sensitivity.
Question 2: What is the primary purpose of using a reference radiograph in a quality assurance program?
- To document patient exposure history
- To serve as a standard against which current images are compared (Correct answer)
- To calibrate the X-ray tube output
- To satisfy OSHA record-keeping requirements
Correct answer: To serve as a standard against which current images are compared
A reference radiograph provides a baseline standard of acceptable image quality for ongoing comparison and quality monitoring.
Question 3: A dental office notices that radiographs consistently show increased contrast but reduced overall density. The MOST likely cause is:
- Developer solution that is too warm
- Developer solution that is too cool (Correct answer)
- Fixer solution exhaustion
- Insufficient replenishment of fixer
Correct answer: Developer solution that is too cool
Cool developer temperature slows development, reducing overall film density while producing higher apparent contrast due to incomplete development.
Question 4: How often should the automatic processor roller transport system be cleaned according to standard quality control protocols?
- Daily (Correct answer)
- Weekly
- Monthly
- Only when image quality problems arise
Correct answer: Daily
Automatic processor rollers should be cleaned daily to prevent chemical carryover, artifact formation, and contamination between developer and fixer tanks.
Question 5: Which type of artifact appears as a herringbone or tire-track pattern on a processed radiograph?
- Reticulation artifact
- Pressure artifact
- Reversed film placement artifact (Correct answer)
- Static electricity artifact
Correct answer: Reversed film placement artifact
A reversed film placement artifact (embossed dot pattern) appears as a herringbone or tire-track pattern caused by X-rays passing through the lead foil backing.
Question 6: In a quality assurance program for digital radiography, which test specifically evaluates the detector's ability to display the full range of gray shades?
- Spatial resolution test
- Dynamic range evaluation (Correct answer)
- Noise assessment
- Uniformity test
Correct answer: Dynamic range evaluation
Dynamic range evaluation assesses whether the digital detector can accurately capture and display the full spectrum of densities from lightest to darkest.
Question 7: What corrective action should be taken when the sensitometric chart shows a gradual upward drift in base plus fog density over two weeks?
- Replace the safelight filter
- Replenish or replace the developer solution (Correct answer)
- Increase developer temperature
- Replace the fixer solution
Correct answer: Replenish or replace the developer solution
A gradual upward drift in base plus fog density indicates developer exhaustion or contamination, requiring replenishment or complete replacement.
DRC Quality Control & Process Improvement 2
Which sensitometric step on a film should be used to monitor the speed point in a quality control program?