1. IMAGE ARTIFACTS

2. What is an ARTIFACT
Any irregularity on an image that is not caused by the proper shadowing of tissue by the primary beam.
an undesirable optical density on radiograph

3. How are they produced?
Exposure
Processing
Handling & Storage

4. ARTIFACT FROM EXPOSURE
Associated with conducting Exam
Equipment
Incorrect film screen match or poor contact
Warped or dirty cassettes
Grid misalignment
Patient
preparation or instruction (motion)
positioning errors
technical errors

5. ARTIFACTS FROM PROCESSING
Pressure marks from transport of film
produced during processing and will usually appear with a higher OD
Roller Marks
Dirty Rollers
Chemical Fog
Wet-Pressure Sensitization

6. ROLLER MARK
Guide Shoes-mark on leading or trailing edge of film, found parallel to the film travel direction. Caused by improper positioned guide shoes or spring shoes
pi lines inch intervals
dirt and chemical stains

7. DIRTY ROLLERS Emulsion Pickoff Gelatin buildup- sludge
Can appear as sharp positive or negative optical density on film

8. CHEMICAL FOG Improper or Inadequate processing chemistry
Chemical Fog- uniform dull grey
Dichoic Stain- 2 colors
yellow, green, blue, purple
Curtain Effect-chemistry running up trailing edge or down leading edge

9. WET PRESSURE SENSITIZATION
Developer tank
Irregular or dirty rollers
Small circular increased optical density

10. HYPO RETENTION Hypo - fixing agent ammonium thiosulfate
Improper washing
Yellowish discoloration to stored
radiograph

11. HANDLING & STORAGE Radiation and Light fog Rough Handling- kink marks
Static
Hypo retention
Kinks
Scratches

12. ARTIFACTS FROM RADIATION AND LIGHT FOG
Light leaks
Safelight
Radiation
Heat/humidity
below 68 degrees
40 to 60 % humidity

13. HANDLING Kink marks Scratches Fingerprints Darkroom environment
Before or After processing
Kink marks
Scratches
Fingerprints
Darkroom environment
clean dry surfaces

14. STATIC
Electron buildup on emulsion
Low humidity
Crown
Tree
Smudge

15. CASSETTE BASED FILMLESS ARTIFACTS Digital Radiography and PACS pg 90-98
IMAGING PLATE ARTIFACTS
CRACKS –AREAS OF LUCENCY
Adhesive tape residue
Static causing hair to adhere to plate
Backscatter

16. CASSETTE BASED FILMLESS ARTIFACTS Digital Radiography and PACS
PLATE READER ARTIFACTS
Extraneous line patterns caused by electronics
White lines (horizontal) dirt on light guide of reader
Loading of more than one IP into a cassete=double exposure artifact
Grid orientation so that grid lines are parallel to the plate reader’s laser scan = moire pattern. (Grids should be high frequency and grid lines need to run perpendicular to the laser scan line

17. CASSETTE BASED FILMLESS ARTIFACTS Digital Radiography and PACS
Printer Artifacts
Fine white lines from debris on mirror in printer
Operator ARTIFACTS
Insufficient collimation = incorrect exposure range (S) reading
Backward cassette
Underexposure = quantum mottle

18. DR Processing Artifacts
Electronic rather than chemical
Artifacts caused by interference with electronic components

19. CR Handling and Storage Artifacts
Debris on image receptor
Discoloration of fluorescent screens
Fogging
“ghost images”
“dead” detector images

20. Cassetteless Artifacts Digital Radiography and PACS pg 108
Conversion from x-ray to digital is very fast
Potential for signal loss
Electronic noise – most typical of artifact
Rapid exposures can cause lose of signal=reduction of image quality