7. ERRORS of dental x ray might happen.ppt

Xray errors in dentistry

1. RADIOGRAPHIC
ERRORS
HishamAbbas
Ass. Professor & Consultant
Oral & maxillofacial Radiology Department

2. CLASSIFICATION
TECHNIQUE
ERRORS
PROCESSING
ERRORS
EXPOSURE
ERRORS

3. TECHNIQUE
ERRORS
1.PATIENT POSITION
2.FILM POSITION
3.POINT OF ENTRY
4.VERTICAL ANGULATION
5.HORIZONTAL ANGULATION

4. Errors related to the patient

5. Blurred image
Due to movement
of the patient,
film or machine

6. RO artifact
-Any metallic objects
should be removed
-Dental appliances
and jewelry left in
place will appear as
RO superimposed
over the image

7. Phalengioma
-The patient holds
the film by two
fingers
-The patient finger
is exposed and
appear on the final
image

8. Film placement errors

9. Exposure of the film
twice
1. Double image

10. 2. Incorrect
film
placement
-For ant. Teeth
Long dimension
-For post. Teeth
Short dimension

11. 3. Back side
film
projection
(Herring bone
defect)
-If backside
placed towards
the tube
1.Pattern of lead
foil appears on
image
2.Faint image

12. 4. Printed dot
artifact
-Embossed dot
should be placed
occlusally
-If placed apically
Misinterpreted as
PA pathosis

13. 5.(2-4)mm should
be left uniformly
from occlusal or
incisal edge
< 2-
4mm
Crowns
not
shown
> 2-
4mm
Apices
not
shown

14. 6. Dropped
film corner
(tilted occlusal
plane)
-Film edge should
be parallel to
incisal or
occlusal plane
-If not
Tilted occlusal
plane

15. 7. Distortion
-Over bending of
the film due to
over pressure by
the pt’s finger
while holding the
film
(Bended area will
have incorrect
angulations)

16. 8.Excessive film bending
White
line
Black
line
Excitation and
Ionization of
Emulsion layer
Removal and
scratching of
Emulsion layer

17. Black
line

18. White
line

19. 9. Area of interest not shown
-If area of interest
is not centralized
in the film

20. Projection
errors

21. 1.Improper point
of entry
(POE [ ROI ] not in
the centre of the
cone)
Cone cut
(curved border)

22. 2. Incorrect
horizontal
angulation
(CR not directed
through
interproximal
spaces)
Horizontal
overlapping

23. 3.Improper vertical angulation

24. VA
Shortening
VA
Elongation

25. exposurE
ERRORS
1.mA
2.Exposure time
3.kVp
4.TFD
5.Object
6.Film

26. mA
Faint
image
mA
Dark
image
Milliampere
mA affects the QUANTITYof the beam

27. ET
Dark
image
Exposure time
ET affects the QUANTITYof the beam
ET
Faint
image

28. kVp
Dark
image
kilovolt
kVp affects the QUALITYof the beam
kVp
Faint
image

29. Target-film distance
TFD affects the QUANTITYof the X-ray
photons reaching the film
TFD
Faint
image
TFD
Dark
image
Acc. To INVERSE SQUARE LAW
I = 1/d
2

30. D,Th,At no
Faint
image
Object characteristics
Density, thickness, and atomic no affect
the QUANTITYof the X-ray photons
Reaching the film
D,Th,Atno
Dark
image

31. Film speed
Constant exposure parameters
Fast film
Dark image
Slow film
Faint image

32. Exposure errors
1.High mA
2.Long ET
3.High kVp
4.Short TFD
5.High film
speed
6.Low
object
D, Th, At no
Dark
image

34. Exposure errors
1.Low mA
2.Short ET
3.Low kVp
4.Long TFD
5.Low film
speed
6.High
object
D, Th, At no
Faint
image

36. Unexposed
Film
Blank image

37. processing
ERRORS
May be caused by:
Developer
Fixer
Improper
handling

38. Developer Errors

39. Dark image
developing time
developer
concentration
developer
temperature

40. Faint image
developing time
developing
concentration
developer
temperature

41. Black spots or
patches
Contaminated hanger.
Contaminated working
table with the developer.
Over development of some
areas of the film.
(Developer contamination)

42. Developer cut
off
The film is not
immersed
completely in the
developer solution.
Appear as straight
line (part of the
image appear
white).

43. Yellowish brown discoloration
Exhausted developer (oxidized developer
is brown)

44. Fixer Errors

45. Dark image
Under fixation

46. Faint image
Over fixation

47. Fixer
contamination
Before
Developing
After
Developing

48. Before
developing
White spots /
patches
Contaminated
hanger.
Contaminated
working table with
the fixer.
(Over fixation of
some areas of the
film).

49. After developing
Yellowish brown discoloration
•Insufficient washing.
•Insufficient fixation.

50. Fixer cut off
The film is not
immersed
completely in the
fixer solution.
Appear as straight
line (part of the
image appear
black).

51. Blank image
-The plastic base of
the film with its
transparent blue
tinted colour
-Due to placement of
the film in the fixer
solution first

52. Improper handling

53. Overlapped
films
In Fixer In Developer

54. Overlapped
films
Crowding of films in
the fixersolution
prevents the action
of the fixer over
some areas on the
film.
(black areas)

55. Overlapped
films
Crowding of films in
the developer
solution prevents
the its action over
some areas on the
film.
(White areas)

56. White spots
-Air bubbles on the
film prevent the
developer action
-Films must be
agitated gently in
the solutions
-Dust or foreign body
over the
intensifying screen

57. Finger nail
artifact
Excessive
pressure
Severe
pressure
Excitation and
Ionization of
Emulsion layer
Removal and
scratching of
Emulsion layer

58. Black
crescent
(finger nail)
-Appears black due
to excessive
pressure on the
emulsion
Excitation and
Ionization of
Emulsion layer

59. White
crescent
(finger nail)
-Appears white due
to severe pressure
on the emulsion
-Removal of emulsion
layer

60. Pinball writing error
A
A
Over pressure
Severe pressure

61. Static electricity
(Black tree appearance )
During taking the films
out of the boxes or
packets rapidly, friction
lead to static electricity
from their rubbing
together.
Electricity with visible
light exposes the film.

62. Reticulation
(cracked appearance)
1.Over drying.
2. Excessive fixer acidity
3. Extreme temperature
changes between
processing solutions
and rinsing water.

63. Finger
smudge
(finger print)
-Contaminated
finger with the
developeror the
fixer touches the
film before
processing.

64. Saliva
(moisture)
contamination
-Saliva leak through
the cardboard outer
wrapping and
cause sticking
between the black
paper and the film

65. White
scratches
-Removal of the
emulsion by
fingernails, tank
wall, or metallic
hangers due to
careless handling
-When the film is
wet, the emulsion is
soft

66. Fogging
Uneven cloudy appearance on the final image.
Causes of fogging:
*Light *Radiation *Chemicals *Storage