Quality Assurance And Fault Analysis

Question 1

What is the purpose for quality assurance?

Answer 1

Ensure consistently adequate diagnostic information while keeping radiation doses to patients and others ALARP taking into count IRMER17 and IRR17

Question 2

What checks are done on image receptors?

Answer 2

Check receptor
- any damage to casing or wiring
- is it clean?

Check image uniformity
- expose receptor to unattenuated x-ray beam to check if result is uniform

Check Image quality
- use test object to check the baseline

Question 3

How would damage affect the receptor?

Answer 3

Phosphor plates:
Scratches or cracking typically form white lines
Delaminating appears as a white area around an edge

SS Sensors:
- sensor damage leaves white squares or straight lines

Film:
- damage often appears as black marks
- can be white if emulsion scraped off

Question 4

What can be used to check image quality and contrast?

Answer 4

Using a step wedge to create different thickness of lead foil then exposing it to radiation

Must be able to detect all 6 steps

Question 5

How is clinical image quality assessed?

Answer 5

1. Image quality rating
   - grade each image
2. Image quality analysis
   - review images to calculate success rate
3. Reject analysis
   - record and analyse each unacceptable image

Question 6

What makes a bitewing diagnostically acceptable?

Answer 6

Must be able to see crowns of all teeth

Capture distal of canine

Capture mesial of last standing tooth

Show every approximal surface without overlap

Also adequate contrast, sharpness and resolution

Question 7

What makes a periapical diagnostically acceptable?

Answer 7

Show entire root

Show periapical bone

Show entire crown

Also adequate contrast, sharpness and resolution

Question 8

What are some possible faults with radiographs?

Answer 8

Distortion
Over collimation
Receptor damaged
Poor positioning
Poor contrast
Not sharp
Too dark or pale