Quality assurance 2 Flashcards
what causes a pale or weak image? 5
Incorrect exposure selected -> not enough radiation -> underexposed
Film not in developing tank long enough
Exhausted developer
Chemicals not diluted correctly
Temperature of developer too low
how to prevent a pale/weak image? 5
Following quality assurance programme
Sensitometry testing and routine processor maintenance
Check x-ray tube output
Select correct exposure output
Top up developer when required
what has caused the speckled areas on the phosphor plate?
underexposed areas
this is a pale/weak image
what are these dark areas called?
fogging
what causes fogging? 2
Light leakage from incorrect storage
Light leakage into glovebox of processor from incorrect handling
- Leakage into glove box of processor
how is fogging prevented? 4
○ Quality assurance programme
○ Coin test in glove box
○ Correct storage of film
Staff appropriately trained
this is an example of a dark image
what causes a dark image? 2
Too high exposure
Processing fault
- Film too long in developer tank
- Temperature of developer too high
- Developer not diluted enough
how is dark image prevented? 4
Quality assurance programme
Routine maintenance of processor
Check developer temperature regularly
Staff training
this is an example of green/yellow tinted film
what causes green/yellow tinted film?
Insufficient fixing during processing
- Time
- Temperature
- Dilution
how is green/yellow tinted film prevented?
Processor maintenance
Topping up fixer when required
patterns on the image can be caused by what? 3
chemicals
static electricity
damaged pixels on solid stated sensor
what causes this patterning?
Chemicals not properly washed from film during processing
Dark spots from developer splashed
Clear spots from fixer splashes
how is chemical patterning prevented?
processor maintenance
what causes this black patterning?
static electricity from Film pulled quickly from packet when atmosphere is dry
how is static electricity patterning prevented?
Darkroom is well ventilated
Correct storage and handling
what has caused this dark patterning of the lower left corner?
damaged pixels on solid state sensor
what has caused this white line artefact on phosphor plate image?
Speck of dust on sensor on the processing tower blocking data transfer from a line of pixels
how is white line artefact from dust prevented?
Careful handling
Regular maintenance
Phosphor plates and sensors scanned monthly for damage
notice the scratches and delamination of sides of this phosphor plate image
what has caused the phosphor plates to not function properly creating this image?
Extreme temperature change
phosphor plate damage
what are these scratches and marks on DPT caused by?
Foreign bodies -> works in metal factory, wielding or exposed to high velocity metal specs
Poor film handling
Dust in cassette
whats wrong with this image?
Film packet back to front
- Lead foil partially absorbed x-rays
- Underexposed image
Not acceptable
whats wrong with this image?
Crimp marks and scratches from poor handling
Not acceptable
whats wrong with this image?
Wrong size of receptor
Not acceptable
whats wrong with this image?
Bone levels missing due to collimation
whats wrong with this image?
Corner of film bent over
Cusps separated
Just acceptable
whats wrong with this image?
Glasses on film
Green tint from incorrect fixing
Not acceptable
whats wrong with this image?
Double exposed film (used twice)
Not acceptable
whats wrong with this image?
Bend
Nail marks in emulsion
Blurred from patient movement
Not acceptable
whats wrong with this image?
Earrings -> ghosting
Narrow incisors -> too far forwards
Air shadow -> tongue not against palate
Not acceptable
whats wrong with this image?
Glasses
Nose ring
Hair extensions
Acceptable -> no detriment to area of interest
