Radiology 15 Flashcards
What could’ve been the fault here?
- Incorrect selection of exposure factors – not enough radiation equals an underexposed image.
- Film didn’t spend enough time in the developer tank
- Developer is exhausted or at too low a temperature.
- Incorrect dilution of chemicals
What could’ve been the fault here?
Incorrect exposure factor selection on a phosphor plate. The speckled white areas have just not had any exposure to radiation, so the phosphor crystals cannot emit light, because no interaction with radiation has occurred. Consequently there is no information for the computer software to convert into a shade of grey from those particular pixels.
What could’ve been the fault here?
Firstly it looks like a size 2 has been used for anterior teeth, it should always be a size 0. There is also collimation along 2 edges which means the tube is not sitting with all 4 corners touching the guide ring. The film is damaged with several scratches and marks, and it is under exposed.
Main ways faults can be prevented
- Sensitometry
- Routine processor maintenance
- Topping up developer when required
- Appropriate exposure selection
What could’ve been the fault here?
We have an area of fogging down the left hand side. This means the film has either been exposed to light leakage before it has been exposed through incorrect storage, or it has been handled wrong during processing, possibly from light leaking into the glove box of the processor. The image itself isn’t the best as the teeth are quite elongated and the apices are missing as a result. This is caused when the vertical angulation of the tube or film is wrong.
What could the fault have been here?
This image is also fogged along the bottom of the film over the crowns. I would say this image is also affected by movement artefact. This image is quite blurred which suggests that the patient has moved during the exposure.
How can fogging be prevented? (3)
- Regular checking of glovebox/darkroom
- Coin test
- Appropriate staff training
What could the fault have been here?
- Incorrect exposure factors selected - too high an exposure will give a dark image.
- Film spend too long in the developer tank
- Temperature of the developer too high
- Developer not diluted enough when it was changed
How can processing faults be prevented?
By routine maintenance of the processor and regular checking of the developer temperature. Having a robust QA programme including regular staff training, will reduce the chances of these problems occurring.
What could the fault have been here?
This is caused by insufficient fixing during processing. Again think of time, temperature, dilution.
What could the fault have been here?
Caused by chemicals not being properly washed from the film during processing. Other splash marks to look out for are dark spots caused by developer splashes and clear spots caused by fixer splashes.
What could the fault have been here?
Caused by static electricity discharging on the film. It often resembles a lightning strike or a tree. It can be caused when a film is pulled quickly from the packet when the atmosphere is dry.
*Prevented by making sure darkroom is well ventilated and film is stored correctly.
What could the fault have been here?
This image has been produced on a solid state sensor, the curved marks on the bottom left corner are damaged pixels on the sensor resulting in artefact. There is also an area where no x-rays have reached the sensor where the 8 is overlying the oblique ridge on the mandible. The combined densities of the structures have absorbed all the radiation and prevented a reaction occurring with the pixels in the sensor.
What could the fault have been here?
This is a phosphor plate image. The white line artefact is a spec of dust on the sensor in the processing tower which has blocked the transfer of data from one line of pixels.
*Prevented by careful handling of digital equipment. Any scanners or processing towers should be regularly maintained by service engineers, and phosphor plates and sensors should be scanned monthly and checked for damage. The results of which should always be recorded in your QA programme.
What could the fault have been here?
Phosphor plate is damaged and should no longer be used.
What could the fault have been here?
- This is a DPT image which again has scratches and marks overlying the anatomy.
What could the fault have been here?
Images which have been taken on damaged phosphor plates.
*exposing plates to extreme changes in temperature will damage the phosphor layer and prevent it from functioning correctly.
What could the fault have been here?
Film packet back to front – foil marks visible. The lead foil has partially absorbed the x-ray photons giving an under exposed image.
Not acceptable.
What could the fault have been here?
Crimp marks – Nail marks and scratches on the film emulsion due to poor handling.
Not acceptable.
What could the fault have been here?
Wrong size of receptor used.
Not acceptable.
What could the fault have been here?
Bone levels missing due to collimation.
Not acceptable.
What could the fault have been here?
Corner of film bent over, cusps separated and teeth slightly elongated.
Just acceptable.
What could the fault have been here?
Corner of film bent over, cusps separated and teeth slightly elongated.
Just acceptable.
What could the fault have been here?
Bisecting angle technique, elongated and no apice on film.
Not acceptable.
What could the fault have been here?
Glasses on film. Brown tinge from incorrect fixing.
Not acceptable.
What could the fault have been here?
Glasses on film causing image artefact. Patient position not great, chin slightly high. Just acceptable.
What could the fault have been here?
Double exposed film. (Used twice).
Not acceptable.
What could the fault have been here?
Digital sensor cable in front of sensor causing artefact.
Not acceptable.
What could the fault have been here?
2 positioning faults. Frankfurt plane not parallel to the floor, chin too far down. Patient is rotated, uneven molar sizes. Not acceptable.
What could the fault have been here?
Film has a big bend across middle and nail marks in the emulsion, image blurred from patient movement.
Not acceptable
What could the fault have been here?
3 faults. Central air shadow from tongue not being against the palate. Earrings not removed, ghosting. Narrow incisors from patient being too far into the machine.
Not acceptable.
What could the fault have been here?
Face mask pulled down under chin, metal strip in nosebar causing artefact.
Acceptable, no detriment to image
What could the fault have been here?
Facial piercings, metallic artefact.
Not acceptable.
What could the fault have been here?
Artefact on image from nose ring and hair extensions.
Acceptable, no detriment to area of interest.
What could the fault have been here?
Glasses not removed, broad unsharp incisors caused by mandible being too far out of machine and not in the focal trough.
Just acceptable.
