Quality assurance and Fault analysis of Radiographs Flashcards
What is the purpose of quality insurance in dental radiology according to guidance notes?
- Purpose is to ensure consistently adequate diagnostic info, whilst radiation doses to patients and other persons are kept at ALARP, taking into account relevant requirements of IRMER17 and IRR17
What aspects should the Quality assurance programme cover of using radiographs?
- Procedures (e.g. risk assessments, local rules, contingency plans, etc.)
- Staff training
- X-ray equipment
- Patient dose
- Image processing
- Display equipment
- Image quality
What are the things you should check when looking at QA of digital image receptors?
- Receptor itself
- Image uniformity
- Image quality
When should digital image receptors be checked?
- Formally checked on a regular basis
- Every 3 months or sooner if issues suspected
- Wear and tear and mishandling will eventually impact quality and necessitate replacement
How to check the digital image receptor?
- The receptor
* Check for visible damage to casing/wiring
* Check if clean (e.g. no congealed disinfectant/saliva) - Image uniformity
* 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) - Image quality
* Take a radiograph of a test object & assess the resulting image against a baseline
How does receptor damage on Phosphor plates affect image?
- Scratches → white lines
- Cracking (from flexing) → network of white lines
- Delamination → white areas around edge
- i.e. separation of phosphor layer from base plat
How does receptor damage on Solid-state sensors affect image?
- Sensor damage leads to white squares/ straight lines
How does receptor damage on Film affect image?
Damage often appears as black marks due to
sensitisation of radiographic emulsion
* However, may appear white if emulsion is scraped off
- May represent nail marks, bite marks, fingerprints etc
What is a step wedge?
- Type of test object used to check image quality/contrast
- Exposed to normal clinical exposure like adult mandibular molar periapical and the resulting image is compared to a baseline
- Carried out regularly like every morning
What is the aim of QA of clinical image quality?
- Ensure radiographs are consistently adequate for diagnostic purposes
- Action must be taken if non-diagnostic images occurring too frequently or if same issues keep arising
What are the 3 parts QA of clinical image consist of?
1.Image quality rating
* Grading each image
- Image quality analysis
* Reviewing images to calculate “success rate” & identify any trends for suboptimal images
* Carried out periodically (e.g. every 4 months you review the last 150 images) - Reject analysis
* Recording & analysing each unacceptable image
Where can you find the recommended QA system for clinical image quality?
- Guidance notes for dental practitioners on the safe use of X-ray equipment
- FGDP
What constitutes a diagnostically acceptable radiograph?
- No errors or minimal errors in;
- Patient prep
- Exposure
- Positioning
- image (receptor) processing or image reconstruction
- Sufficient image quality to answer the clinical question
What does considering the clinical image quality depend on?
- Type of radiograph being taken
- Clinical justification for taking it
What are the diagnostically acceptable positioning factors for bitewing radiographs?
Show entire crowns of ↑ & ↓ teeth
* Include distal aspect of the canine, & mesial aspect of the last-standing tooth
* May require >1 radiograph
* Every approximal surface shown at least once without overlap (where possible)
* May be impossible if crowding
