Transcript Topic 2
Artifact analysis One of the causes of rejected images listed in the repeat analysis worksheet is the presence of image artifacts. An artifact can contribute significantly to the total repeat rate; therefore a thorough knowledge of artifacts and their possible causes is necessary so that corrective action can be taken. What Is An Artifact? Any optical density that is not anatomy An unwanted density on the radiograph Interferes with diagnosis There Are Three Time Periods In Which Artifacts Can Occur During exposure During processing 1 1 3 During film handling, prior to processing, loading cassette, or storing Exposure Artifacts They are caused by the patient, the technologist, or the equipment during a diagnostic procedure Poor screen-film contact Improper use/positioning of a grid Double exposure Patient motion Poor patient preparation Clothing, jewelery, glasses, belts, etc. Processing Artifacts They are caused by or occur during the processing of diagnostic images Dirty Rollers Will leave deposits on film Areas of increased or reduced density Occasionally some sludge may not be washed off and dried onto the film Chemical Fog Improper or inadequate chemistry Leaves a uniform dull gray haze on the film May also be seen in two different colors Referred to as dichroic stain Guide Shoe and Roller Marks Guide shoes are sprung or improperly positioned The ridges in the guide shoe press against the film leaving an artifact Pi-lines Dirt or stain on a roller 3.14 inches apart Pressure marks Irregular or dirty rollers Small, circular patterns are produced Hypo Retention Yellowish stain that appears on finished radiograph Due to inadequate washing Remaining thiosulfate from fixer solution Handling And Storage Artifacts They occur during darkroom handling or during storage before use. Light or Radiation Fog White light streaks Safelight too close or wrong wattage Film left in x-ray room during exposure Kink Marks Improper handling or storage Appears as a fingernail mark Static Caused by buildup of electrons in the emulsion Three types of static artifacts Crown Tree Smudge FILMS STUCK TO EACH OTHER DURING PROCESSING HYPORETENTION ROLLER MARKS PI-LINE GUIDE SHOE MARK WATER STAIN STATIC (Tree Static) STATIC (Crown Static) STATIC (Smudge Static FINGER MARKS CRIMPING MARK CRIMPING MARK PICK-OFF WATER STAIN WATER STAIN MOTION POOR FILM SCREN CONTACT ARTIFACT???? H.T. (high Voltage) CABLES ROTATION + FOG DOUBLE EXPOSURE BACKSCATTER OR CASSETTE UPSIDE-DOWN BACKSCATTER BACKSCATTER OR CASSETTE UPSIDE-DOWN MOIRE EFFECT Are artifacts also called zebra pattern Artifact It is a double set of grid lines caused by the placement of a grid cassette in a Bucky tray. WARPED CASSETTE-LIGHT LEAK HAIR BUN CLOTHES RIBBING TUBE HAIR STREAKING GRID CUT-OFF JEWELLERY HEARING AID LIGHTER IN THE POCKET SCATTER FOG SANDBAG UMBILICAL RING AIR IN THE VENTRICLES AIRHEAD????? PLASTER DIRT ON THE SCREEN PATHOLOGY FOGGING KYPHOSIS-CHIN STRAP SCRATCHES STATIC Intra Uterine Device Chole clips Earring Artifact Patient Movements