Download presentation
Presentation is loading. Please wait.
1
Moderator : DR.UMA MAHESWARI presentor : dr.a.p.jaganathan
X-RAY ARTIFACTS Moderator : DR.UMA MAHESWARI presentor : dr.a.p.jaganathan
2
DEFINITION Artifact (or Artefact) is a non anatomical image observed in radiography. An unwanted density on the radiograph Interferes with diagnosis.
3
SOURCES OF ARTEFACT X-ray tube Imaged object Grid X-ray film
Image intensifying screen Others
4
1. X RAY TUBE ARTIFACTS Anode –heel effect Collimator
5
1. X RAY TUBE ARTIFACTS Anode –heel effect Collimator HEEL EFFECT
Refers to a reduction in the x-ray beam intensity toward the anode side of the x-ray field Magnitude depends on anode angle, FFD & film size
6
1. X RAY TUBE ARTIFACTS Anode –heel effect Collimator Reduced by
Keeping the film at a longer distance from the source Increased anode angle Using small films. By keeping thicker parts of the body placed at cathode side with higher intensity of x-rays
7
1. X RAY TUBE ARTIFACTS Anode –heel effect Collimator
8
1. X RAY TUBE ARTIFACTS Anode –heel effect Collimator
Due to collimator malpositioning Back…
9
2. IMAGED OBJECT ARTIFACTS
Movement unsharpness Magnified distortion Ornaments,prosthesis,etc
10
2. IMAGED OBJECT ARTIFACTS
Movement unsharpness Magnified distortion Ornaments,prosthesis,etc Due to movement of any of the components of the imaging chain namely focal spot ,imaged object (mc),film screen system Motion artifacts
11
2. IMAGED OBJECT ARTIFACTS
Movement unsharpness Magnified distortion Ornaments,prosthesis,etc Alteration in size ,shape or relative proportion of an object’s components due to varying distance of the components from the film level Eg. Magnification of heart in AP view of x-ray chest
12
2. IMAGED OBJECT ARTIFACTS
Movement unsharpness Magnified distortion Ornaments,prosthesis,etc Back… HAIR ARTIFACT
13
3. GRID ARTIFACT GRID Used to reduce the scattered radiation reaching the film cassette
14
3. GRID ARTIFACT MALALIGNMENT OF GRID
15
3. GRID ARTIFACT LATERAL DECENTERING & FOCAL DECENTERING
16
3. GRID ARTIFACT If the grid stops moving while taking X-ray because of nonfunctioning bucky or short exposure time Back…
17
4. X-RAY FILM Improper exposure Improper handling Improper processing
Aka SOLARISATION means over exposure when the film is exposed beyond the time required, there is decreased density of the image
18
4. X-RAY FILM Improper exposure
19
4. X-RAY FILM Improper exposure double exposure
20
4. X-RAY FILM Improper exposure Improper handling Improper processing
If covering paper is not removed
21
4. X-RAY FILM Improper handling If film is not caught at the corners –CRIMP MARKS and finger prints are seen Minus density finger prints – if touched with moist fingers prior to exposure Positive density - if touched after exposure but prior to processing
22
4. X-RAY FILM Static marks Improper handling
due to discharge of static electricity produced by friction or pressure Filigree pattern Smudge pattern
23
4. X-RAY FILM Static marks Improper handling
due to discharge of static electricity produced by friction or pressure Avoided by humid atmosphere cotton dress touching grounded object before the film opening cassettes slowly not pulling the film rapidly from holders
24
4. X-RAY FILM Improper handling Improper handling of cassettes – film exposed to light before developing
25
4. X-RAY FILM Improper handling Film handling artefects
Dark room was opened before the film was fed into the developer
26
4. X-RAY FILM Improper handling Two exposed films placed one above another after removing from the cassette, before processing in the dark room
27
4. X-RAY FILM Kink marks When the film is not handled at the corners during processing – crescent shaped nail marks occur Improper handling
28
4. X-RAY FILM Finger Prints
When the xray film is touched prior to exposure – “MINUS DENSITY FINGER PRINTS” When the film is touched after the exposure but prior to processing - “ POSITIVE DENSITY FINGER PRINTS” Improper handling
29
4. X-RAY FILM Improper exposure Improper handling Improper processing
Processor derived Developing Rinsing Fixing Washing
30
4. X-RAY FILM Improper processing Processor derived Developing Rinsing
Fixing Washing
32
Processing artefacts :
Dirty rollers : Leave deposits on the film Appear as areas of increased / decreased density Occasionally some sludge may not be washed off and may be dried onto the film
33
Run back artefacts: Look like fluid drips at the trailing edge of the film. The upper rollers in the processor are designed to remove the excess chemicals before the film moves to the next tank If these excess chemicals are left behind runback artifacts occur Prevented by proper cleaning of the cross over rollers.
34
Scratches Black scratches: before the film goes into the fixer
Clear scratches happen in the fixer, wash or drier assemblies
35
Shoes marks : Several types of shoe marks can occur.
Result when film rubs against guide shoes during transport Manifests as a series of evenly spaced lines parallel to the direction of film transport Plus-density marks are caused by the guide shoes in the developer tank Minus-density shoe marks often occur in the fixer-to-washer crossover
36
Guide shoe scratches Guide shoes marks are parallel and run in the direction of film travel
37
Hesitation scratches:
Parallel, widely spaced scratches Due to bad rollers in roller racks in the chemical tanks
38
Tractor marks : When the film is jammed in the processor. Back…
39
Developing defects Fogging Exhausted developer Contaminated developer
Dirt in the developer tank Kissing artifact Poor agitation of developer Insufficient developing time
40
Developing defects Fogging :
Fogging occurs due to increased density of the silver bromide crystals which were unexposed during the process of taking the x ray. Leaves a uniform dull gray haze on the film Causes : i. due to storage in warm, humid environment ii. prolonged storage time Can occur in 2 different colors “DICHOIC STAINS”
41
White fog :
42
Exhausted developer When the developer goes bad due to inadequate replenishment, the latent image is not developed before the image is fixed and washed
43
Contaminated developer
44
Dirt in the developer tank
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.
45
KISSING ARTIFACT When two films stick together during developing process
46
Poor developer agitation
Mottled streak like densities - lack of proper agitation of developer
47
Insufficient developing time
Yellow coloured Back…
48
Improper rinsing When the rinsing solution is contaminated with the developer Back…
49
Improper fixing If gets splashed before developing, white areas are seen Back…
50
Improper washing 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
51
hyporetention Yellowish stain that appears on finished radiograph
Due to inadequate washing Remaining thiosulfate from fixer solution
52
Improper washing If inadequately washed the film becomes brown with age due to silver sulphonate deposition Back…
53
5. IMAGE INTENSIFYING SCREEN
Poor screen film contact
54
5. IMAGE INTENSIFYING SCREEN
Old screens with exhausted phosphorescent chemicals Back…
55
OTHERS Reticulation artifact-wrinkling of film emulsion coz of shrinkage of film base –yrs of storage
56
OTHERS Dirt on the screen
57
others Water stains
58
others Screen Artefacts
Old, worn out screen with exhausted phosphorescent chemicals - white spots
59
others Hearing aid Deodarant
60
others Therapeutic Prostheses
61
Prevention Screen: cleaned monthly with a screen cleaner.
Never use alcohol or detergents for cleaning. Always make sure the light spectrum of the screen and film are matched. Cleaning the rollers on a regular basis – reduces chance of having old developer dried on the roller. Hands are to be clean and dry. Hold the x-ray film in the corners. Maintain humidity in the processing area.
62
Prevention Most patient derived artefacts are avoidable
Check for jewellery, hair clips, use of deo sprays, wet hair, etc The x-ray should be dried in a dust free area. The safe light of the dark room is to be tested periodically to prevent fogging of films.
63
THANK YOU
Similar presentations
