14 - Quality Assurance 2 Flashcards
film faults: pale image - causes?
- insufficient exposure
- insufficient developing time
- use of exhausted/old developer
- developer temperature too low
- incorrect dilution of developer (too weak)
film faults: dark image - causes?
- excessive exposure to x-rays
- excessive developing time
- developer temperature too high
- incorrect dilution of developer (too strong)
film faults: blurred image - causes?
movement of:
- patient
- image receptor
- xray tube
film faults: lead pattern (pale image) - causes?
film exposed through back of packet - image of lead foil
film faults: partial image - causes?
- failure to direct collimator to centre of image receptor
- manual processing: developer level too low and film only partially submerged in developer
film faults: fogging - causes? how does it appear?
- storage of film in adverse conditions
- film out of date
- film exposed to white light
- appears as excessive grey/black areas on film
film faults: black lines (crimp mark) - causes?
- excessive bending of film
film faults: static mark - how does it appear? causes?
- black star burst appearance
- caused by a static electricity discharge
film faults: chemical marks - causes?
- chemicals splashed on film before processing
spillage of: - developer: dark
- fixer: clear
film faults: green tinted image - causes?
- insufficient fixing
film faults: double exposure - causes?
- two images superimposed, receptor used twice without clearing
digital faults: thin white lines on PSP image?
scratched phosphor plate
digital faults: white areas on edge of PSP image?
phosphor coating de-laminating
digital faults: areas of white “burn out”?
PSP underexposed, or plate exposed to light before processing
digital faults: grainy digital image?
under exposed
