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