TECHNICAL ARTIFACTS & ERRORS Lavin: pp CTVT: pp

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Why review artifacts? Definition: Anything that decreases the quality of a radiograph, resulting in difficult evaluation and interpretation Preparation for lab assignments Recognizing artifacts and when they occur is the only way to make good radiographs. If you don’t recognize ‘em, you can’t fix ‘em! It’s possible to make a mistake at any stage of the radiographic process… 3

Categories of Artifacts Knowing at what point in the process an artifact is created can help you fix the problem… Categories: Pre-exposure/Handling Exposure Positioning Obstruction/Materials Processing 4

Pre-Exposure/Handling Artifacts Definition: Artifacts caused before the film is exposed Examples : Quantum mottle Chemical smudges Fingerprints Poor screen/film contact Film fog Blank screen Rough handling Cleaner residue Light leaks Reticulation 5

Quantum Mottle What is it? An underexposure error Dupont intensifying screens have the tendency to absorb moisture, causing a swelling of the emulsion. Appears as tiny raised points or bubbles along the edge of the screen that gradually work their way to the center Develops if clinic is too dusty or humid 6

Screen Defects: Quantum Mottle 7

Screen Defects: Chemical Smudges Can happen at any point of the radiographic process when chemicals are transferred to the film inadvertently 8

Barium behind the screen… 9

Fingerprints Usually show on a film in white Can be caused by: Oil on the fingertips that blocks the developer Fixer on fingertips 10

Poor Screen/Film Contact Causes image to lose sharpness 11

Film Fog 12 Any unwanted exposure of film prior to taking a radiograph Decreases image contrast/detail Causes: Light exposure Heat Humidity Radiation Chemicals Aged film

Film Fog 13 Caused by improper safelight filter

Blank Image Film that didn’t receive any radiation 14

Rough Handling: Creases Abrasions on the image resulting from film mishandling Includes rough removal from the film box Pressure from crease causes activation of crystals Usually not caused by fingernails 15

Screen Cleaner Residue Causes chemical spots that mar the radiograph surface 16

Darkroom Light Leaks 17

Reticulation A darkroom artifact produced by variable chemical temperatures that cause irregular expansion/contraction of the film emulsion Gives a mottled density appearance. 18

Exposure Artifacts Occur during the process of exposing the film Examples: Debris Double exposure Off-Focus radiation Human hands Motion Blur Low density Grid deterioration Static electricity 19

Debris 20 Material on the film or intensifying screen Usually shows as white with sharp margins Occurs when visible light photons from the screen can’t reach and expose the film emulsion

Double Exposure Appearance of 2 images in 1 Caused by film inadvertently exposed more than once Exposure trigger pedal pushed twice Forget to change cassette after first view 21

Off-Focus Radiation “Extrafocal" radiation Produced by electrons bouncing off & impacting the anode outside the focal spot. 22

Human Hand 23

Motion Patient movement resulting in a lack of image sharpness Can be voluntary or involuntary Best controlled by short exposure times Reduce with: Better restraint Sedation 24

Blur Movement of the film, body, or x-ray tube head during exposure 25

Low Density/Faint Density = blackness = x-rays 26

27 Grid Deterioration A worn out grid will put an image of itself on every radiographic image. Gridlines may appear on the radiograph

Static Electricity 28 Can be discharged at any time Usually shows as black Cause is electrical discharge Can be prevented by: Managing humidity Avoiding friction while handling film Antistatic cassette cleaners

Positioning Artifacts caused by patient positioning on the table Examples: Patient Rotation Distortion Magnification 29

Patient Rotation A form of distortion Lesions may be masked by atypical superimposition on normal anatomy 30

Distortion X-ray beam does not pass perpendicular to long axis of structure 31

Magnification 32

Obstruction/Materials Artifacts caused by foreign objects blocking the x-ray beam or otherwise impacting the image Examples: Equipment artifacts Material obstructing the X- ray beam 33

Equipment Artifact In this image, a small screw fell out of the collimator shutter onto the window. Because of the distance to the patient, it is magnified. 34

Material Obstructing X-Ray Beam Caused by any radio- opaque structure in the path of the xray beam Can be: On patient In patient On table On cassette 35

Obstruction in Patient 36

Obstruction in Patient 37

Obstruction in Patient 38

Obstruction on Patient

Processing Artifacts associated with the chemical process Examples: Exhausted chemicals Exhausted fixer Inadequate fixing Roller marks Water spots Under-washed Films stuck together Handling folds Static electricity 40

Exhausted Chemicals Film is processed with exhausted developer Overall image lacks correct density and contrast Washed-out appearance. 41

Exhausted Fixer Film is processed with exhausted fixer. Has a milky appearance and may appear to be pink from the dye used in the green-receiving film. 42

Inadequate Fixing Initially film is cloudy/milky Over time, appears yellow/brown 43

Left in Fixer Too Long 44

Roller Marks Can be caused by unclean or poorly functioning rollers inside the automatic processor 45

Water Spots 46

Under Washed 47 Fixer remains on film Cloudy, sticky residue Yellow-brown stain Sulfur smell

Films Stuck Together 48

Handling Folds in Film 49

Static Electricity Can be released when film is placed into processing tray 50

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