Radiology Errors and Artefacts Flashcards
What checks must you do when taking a panoramic radiograph
- Select exposure factors & correct focal trough size
- Align patient within machine (Frankfort plane/midsagittal plane/canine)
- Check that the patient is standing with a straight spine & relaxed shoulders
- Ask patient to bite incisal edges on bite block
- Patient to stay still and place tongue against
palate - Check & expose
What checks must you do when taking an intra-oral radiograph
- Select correct sensor/film size
- Select correct holder and put together
correctly! - Select exposure settings
- Position sensor within mouth
- Align x-ray tube head
- Check & Expose
When looking at an image we analyse in relation to what 4 topics
- Preparation
- Positioning
- Processing
- Exposure
What are the 3 general things that you need to prepare before a radiograph
X ray area
Specific equipment
Patient
What needs to be prepared in the X ray area before a radiograph
- equipment
- computer acquisition systems
- patient chair & headrest
- processing equipment / phosphor plate scanners
What specific equipment needs to be prepared before a radiograph
- Intra-oral holders
- films/plates
- packets
- bite guides
- sterile covers
- cotton wool rolls
What about the patient needs to be prepared before a radiograph
- Identification
- explanation
- remove jewellery etc.
- position comfortably
Where should the sensing plate be relative to the ring that is used for aiming things
Right in the centre of the ring
Why might you see a straight line that shows no radioactive absorption when the plate isnt in the middle of the ring
Not because the ring is blocking it but because you’re probably using a rectangular collimator so you will have a rectangular radiation beam
What colour is the sensitive side of the phosphor plate
blue
What is the copper dot on the back of a phosphor plate for
If you put a phosphor plate in the wrong way around and the phosphor layer isnt facing the beam you will get an inverted image pretty much and this will make you think it you have scanned one side of the mouth when youve actually scanned the other.
So the copper dot is there to absorb radiation and will show up on the radiograph to tell you you’ve got it wrong
What is the small silver dot used for on a phosphor plate
This is a positiioning dot in the corner that should be placed in the holder so that it is towards the crown. It should be in the slot of the holder – DOT to SLOT !
How can there be edges on the radiograph that have not been exposed properly
- Ring not placed correctly
- Patient has moved it while in the mouth
- If ring is on and bad collimator alignment
- When we place in mouth can be difficult and moves
- Not placed firmly and al
What patient preparation do you need to do before a panoramic radiograph
- Remove all jewellery and appliances
- No Movement
- Tongue against palate
If the patient moves in a panoramic image what happens to the image
The entire image will become blurry