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Chapter 32 Film Artifacts
Retake Analysis
• Required part of a QA program in California.
• Evaluation includes– View repeated– Cause of the repeat
• Rate of retakes should be less than 5%. • Information can be gathered from the log
that the state mandates for patients being exposed to radiation.
Chapter 32 Image Artifacts
• An artifact is any irregularity on an image that is not caused by the normal shadowing of tissue by the primary beam.
• There are three areas where artifacts occur:– Exposure– Processing– Handling
Exposure Artifacts
• Exposure artifacts are generally associated with how the examination was performed. Example include:– Incorrect screen film match or wrong film– Poor screen contact– Warped cassettes– Dirty screens– Improper use of a grid.– Improper technical factors – most common reason for
retakes.
Exposure Artifacts
– Improper preparation of the patient for the exam or gowning instructions.
– Double exposures– Motion blur from improper breathing
instructions.– Improper positioning of the patient and
equipment.
Common exposure artifacts
• Appearance• Unsuspected foreign
objects such as jewelry• Double exposure
• Blur
• Obscured detail
• Cause• Improper patient
preparation• Reuse of an already
exposed cassette• Improper patient
movement, breathing
• Poor screen contact
Dentures
• Older patients may have removable dentures for the upper or lower teeth.
• As part of the gowning instructions ask about dentures.
Dentures
• Partial Dentures are attached to the remaining teeth with metal clips.
• Can cause major problems on APOM views.
Poor Gowning: Ear Rings
• There we see an ear ring on a base posterior view.
Poor Gowning: Ear Ring
• A single ear ring on a lateral cervical spine view.
Poor Gowning: Pins in Hair
• Bobby pins can ruin cervical or skull radiographs.
More Hair
• Here are two A-P cervical spine view.
• One the first view a soft tissue mass is seen at the base of the skull.
• The patient’s hair was in a bun. She put her hair down and the mass disappeared.
More Hair Artifacts
• Another example of mouse and dreadlocks.
• You will not be able to get the patient to remove the dread locks so have the patient but their hair up for the A-P
Hair Extensions
Poor Gowning: Necklace
• When someone measures the patient and positions the view, how can you not see a necklace?
Poor Gowning: Bra
• The complete study of a brassiere.
• P-A & Lateral Views
Patient with arms across chest
• Make sure the arms are to the patient’s sides and out of the view on A-P or P-A views.
Rings and Watch
• The doctor failed to have the patient remove their rings and watch.
Patient with arm to side
• Make sure the arms are properly positioned for lateral views.
Metallic artifacts on Lumbar View
• Intern took film with patient in shorts.
• Shorts had metal eyelets for the drawstrings.
• Something in pocket.
Lateral Gonad Shield
• It is very important to remove the shield after it is used.
• The patient was too large to be done P-A.
Fingers in the spine
• Keep the hands above the lumbar spine when taking the lateral view.
Cassette Artifact Dirty Screens
• Dirty or damaged screens will cause white spots on the image.
Dirty & Damaged Screens
• The white spots on this film are the result of damaged or worn out screens.
• Never use alcohol or detergents to clean screens.
Poor Screen Contact
• Note the blurry image in the spine but sharp image of the ribs.
• The screens were not in proper contact in the middle of the cassette due to a bow in the cassette back.
Processing artifacts
• Processing artifacts are produced during the time the film is in the film processor.
• Processing artifacts can be eliminated with a proper processor quality control program and frequent cleaning.
• Occasionally the best film processor will jam or malfunction and produce artifacts.
Common Processing Artifacts
• Appearance• Guide shoe marks
• Pi lines
• Sharp increase or decrease in OD
• Uniform dull gray fog
• Cause• Improper position of guide
shoes in turn-around assembly.
• Dirt or chemical stains on rollers
• Dirty or warped rollers
• Improper or bad chemistry
Film Guide Scratches
• Guide shoes scratches are parallel and run in the direction of film travel.
Other Processing Artifacts
• Here we see hesitation marks on top of film.
• This film remained in the developer too long. Perhaps from:– Power Failure– Processor jam
Other Processing Artifacts
• This is what contaminated developer looks like.
• Contaminated developer can also appear as a pink film.
Processor Chemical Marks
• This artifact is called a run back artifact.
• Proper cleaning of the cross over rollers can reduce the incidence of this artifact.
Processor Water Marks
• These spots are the result of water spots on the film.
• The upper rollers in the wash tank are supposed to squeegee the film.
Chemical Run Down Artifact
• If the squeegee rollers in the developer rack do not work, the chemicals run down the film forming the appearance of water running down a window.
Kissing Artifacts
• If more than one film is feed into the processor at once, only one side of the emulsion will be completely processed.
Kissing Artifacts
• By running the film through the fixer, the undeveloped emulsion can be fixed and the image will be less degraded.
Kissing Artifacts
• By running the film through the fixer, the undeveloped emulsion can be fixed and the image will be less degraded.
Dirty Developer Rollers
• The rollers in the developer tank or cross over are dirty.
• This causes the black artifacts on the middle of the film.
• Oxidized developer is left on the film.
Tractor Marks from Film Jam
• Marks that appear as tractor tracks on the upper left portion of the film are referred to as Tractor Marks.
• Result of film being feed crocked and jamming the processor.
Film Handling Artifacts
• A number of artifacts can occur while the film is in storage, in the darkroom or in the x-ray room.
• Film is sensitive to heat and humidity.
• After exposure it is very sensitive to fog from lighting problems in the darkroom.
• Improper handling can cause artifacts.
• All handling artifacts are avoidable!!!!
Common Handling & Storage Artifacts
• Appearance• Fog
• Pressure or kink marks• Streaks of increased OD
• Cause• The temperature or humidity
too high.• Safelight too bright, too close
or wrong filter.• Light leak or other light in
darkroom.• Film left in x-ray room during
exposure.• Rough handling of film.• Film not completely in
processor when darkroom door opened.
Common Handling & Storage Artifacts
• Appearance• Crown, tree or smudge static
• Yellow-brown stain
• Cause• Humidity or temperature too
low• Thiosulfate left on film due to
improper washing
Film Handling Artifacts
• Crescent shaped artifact is a nail crinkle mark. It is caused by improper film handling.
• Black spots are scratches from work surface.
Film Handling Artifacts
• The door to the darkroom was opened before the film was completely in the processor.
Film Handling Artifacts
• The top of the film is exposed to light by opening to darkroom door or turning on the lights with the box open.
Film Handling Artifacts
• Some roller artifacts are seen caused by developer being on the entrance rollers.
• Cause: Pulling a film out of the processor feed tray.
Static Electricity
• Static electricity discharge may appear as a tree or lightning strike.
• It may also produce round smudges.
• Keep humidity in area at proper level.
Film Not Left in Box in Film Bin
• The box that the film comes in serves as protection from scratching.
• If you take too many sheets out, replace excess film in box not just in the bin.
Improperly Washed Film
• If the wash tank is not properly filled, fixer is retained on the emulsion.
• The retained fixer form silver sulfide and turns the image brown.
End of Lecture