Quality Assurance and Fault Analysis Flashcards
What is the purpose of quality assurance in dental radiology?
to ensure consistently adequate diagnostic information, whilst radiation doses to patients (and other persons) are kept ALARP, taking into account the relevant requirements of IRMER17 and IRR17
The quality assurance programme is necessary in every dental practise. IT should cover all aspects of using radiographs including what?
Procedures (e.g. risk assessments, local rules, contingency plans, etc.)
- Staff training
- X-ray equipment
- Patient dose
- Image processing
- Display equipment
- Image quality
The quality assurance programme in dental practises should be created with input from who?
A medical physics expert
Why should digital image receptors be checked?
because they are reusable therefore wear and tear (and mishandling) will eventually impact the image quality and necessitate replacement
How often should digital receptors be checked?
formally checked every 3 months or sooner if an issue is suspected
What 3 main things needed to be checked with digital receptors?
- the receptor itself
- image uniformity
- image quality
What do you want to check about the receptor itself? (digital image receptors)
- check for visible damage to the casing/wiring (Not overly bent
- no creases)
- check if clean e.g. no congealed disinfectant from not being dried off properly and no saliva
How do you check the image uniformity when checking digital receptors?
Expose receptor to an unattenuated X-ray beam & check if resulting image is uniform (i.e. should show a consistent shade of grey across the whole image)
How would you check the image quality of a digital image receptor?
Take a radiograph of a test object & assess the resulting image against a baseline
What damage can be seen on phosphor plate receptors? How do they show up?
- Scratches white lines (can be quite large. Shown by red arrows)
- Cracking (from flexing) network of white lines (yellow arrow - due to bending within the mouth etc)
- Delamination white areas around edge
- i.e. separation of phosphor layer from base plate - shown by green arrow. Mishandling or drying out
How will damage show up on solid state sensors?
- white squares/straight lines
- Don’t get as much damage with SS but can damage more sensitive parts in it
- can get digital components failing and get dead pixels (can get single pixels failing or a full line making the white line)
How does damage to film receptors tend to show up?
as black marks due to sensitisation of radiographic emulsion (sensitised by light or presssure etc rather than x-rays)
However, they may appear white if the emulsion is scraped off
Marks on film receptors may represent what?
-nail marks, bites, fingerprints etc
(can lightly scrath the emulsion to make it black by sensitising the crystals. The same goes for the fingerprints)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/343/067/589/a_image_thumb.png?1618667800)
What is a step-wedge and how is used in quality analysis of radiographs?
Is a type of test object used to check the image quality/contrast
It uses overlapping layers of lead foil
The step-wedge is exposed to normal clinical exposure and compared to a baseline (have to see all 6 steps)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/343/067/720/a_image_thumb.png?1618668054)
What is the aim of quality analysis of clinical image quality?
To ensure that radiographs are consistently adequate for diagnostic purposes