MRI for the maxillofacial surgeon.

2. Dr Atef A. Fouda
Prof. Of Oral & Maxillofacial Surgery;
Cairo University .

3. Introduction to

4. 0.2 Tesla

5. 1.5 Tesla
3 Tesla
7 Tesla
11.75 Tesla

6. MRI machines

7. MRI machines

8. MRI machines

9. MRI machines

10. Magnet X120 G
Surface coil

11. MRI surface coil
TMJ surface coil
Head surface coil

12. Hazards

13. Contra indications for MRI
Metal objects
within the eye
Near the spinal cord
Chochlear implants
Insulin pump
Neurostimulator
Aneurysm clamp.
Pacemaker
Things could be destroyed
Magnetic cards and tickets.
Mechanical Watches.

14. Advantages
Safe for pregnant women
Safe for children
Soft tissue clear image
No hazards from dyes
Indications for MRI

16. Water constitutes 80% of the body
Water is composed of two hydrogen atoms
and one oxygen atom
H-O-H
Protons of “H“ act as small magnet
interaction between external magnet of the
machine and internal magnet in the body
hydrogen atoms are dominant

17. Blood
L
H
M
N
0
H
Body content of hydrogen atoms.
Tears-saliva-Inflammatory exudates
-cystic fluid-Edema-Serous Pus-
-Vitreous humor-CSF.-Synovial fluid.
Low water content
Nil water content
No hydrogen atoms
High water content:
Moderate water content
-Fat-Spongy bone-Coagulated blood
-Cortical bone-Tendons-ligaments-Disc

18. H
L
H
M
H
H
M
L
H
H
H
H
Magnetofthemachine
H
H
Body hydrogen atoms.0
H

19. H
L
H
M
H
H
M
L
H
H
H
H
Magnetofthemachine
H
H
0
H
Surfacecoil
ClosedOpen

20. H
L
H
M
H
H
M
L
H
H
H
H
Magnetofthemachine
H
H
0
H
Surfacecoil
OpenClosed

21. H 0
M
L
High signal Low signal
Air
No hydrogen atoms
High water
content
Moderate
water content
Low water
content

22. Magnetofthemachine
Surfacecoil
H
M
L
N
H

23. Magnetofthemachine
Surfacecoil
H
M
L
N
H
T1

24. L
H
T1
Tears-saliva-Inflammatory exudates
-cystic fluid-Edema-Serous Pus-
Coagulated blood
Low water content
High water content:
Fat-Spongy bone

25. Magnetofthemachine
Surfacecoil
H
M
L
N
H
T

26. H
M
T2
Tears-saliva-Inflammatory exudates
-cystic fluid-Edema-Serous Pus-
Coagulated blood
-Vitreous humor-CSF.-Synovial fluid.
High water content:
Moderate water content

27. High signal
“white”
Low signal
“Black”
N
0
Nil water content
No hydrogen atoms
-Cortical bone-Tendons-
ligaments-Disc
N
0
Nil water content
No hydrogen atoms
-Cortical bone-Tendons-
ligaments-Disc

29. “DisK”

30. High signal
“white”
Low signal
“Black”
N
0
Nil water content
No hydrogen atoms
-Cortical bone-Tendons-
ligaments-Disc
N
0
Nil water content
No hydrogen atoms
-Cortical bone-Tendons-
ligaments-Disc

31. Coagulated blood
[Hematoma]

32. High signal
“white”
Low signal
“Black”
N
0
Nil water content
No hydrogen atoms
-Cortical bone-Tendons-
ligaments-Disc
N
0
Nil water content
No hydrogen atoms
-Cortical bone-Tendons-
ligaments-Disc

33. T2T1

34. High signal
“white”
Low signal
“Black”
N
0
Nil water content
No hydrogen atoms
-Cortical bone-Tendons-
ligaments-Disc
N
0
Nil water content
No hydrogen atoms
-Cortical bone-Tendons-
ligaments-Disc

35. T2T1

36. High signal
“white”
Low signal
“Black”
N
0
Nil water content
No hydrogen atoms
-Cortical bone-Tendons-
ligaments-Disc
N
0
Nil water content
No hydrogen atoms
-Cortical bone-Tendons-
ligaments-Disc

38. CSF
T2 T1

39. T1T2
Hematoma

40. Coagulated blood
Hematoma
T1
Tears
Saliva
Inflammatory exudates
cystic fluid
Edema
Serous Pus-
Coagulated blood
T2

41. T1
Epidural
Hematoma
T2
CSF effusion
?

42. T1
T2
CSF effusion

44. H
L
H
M
H
H
M
L
H
H
H
H
Magnetofthemachine
H
H
Body hydrogen atoms.0
H

45. Magnetofthemachine
Surfacecoil
H
M
L
N
H
T1

46. Magnetofthemachine
Surfacecoil
H
M
L
N
H
T2

47. Magnetofthemachine
Surfacecoil
H
M
L
N
H
Flash

48. MRI Angiography
Flash technique

49. MRI-Angiography
AV-Malformation

50. MRI-Angiography
AV-Malformation

52. Disk [Fibrous tissue]
Condyle [Spongy bone]
Condyle [Cortex]
Inflammed Muscles
Synovial fluid
T1 T2
Low “Black”
High “White”
Low “Black”
Low “Black”High “White”
Low “Black” Low “Black”
High “White”
High “White”Low “Black”

53. Disk

54. Disk

56. Anterior displacement without reduction

59. Disk

60. Disk

62. Condyle

63. Synovitis with effusion

64. Retrodiscal effusion

65. Lateral PT m Inflammation
Superior joint space effusion

66. T2
MRI Request
T1
High
“White”
High
“White”
Low
“Black”
CSF
Vitreous
Hematoma
Cysts
Inflammations
Fat
Bone marrow
Hematoma
Dermoid cyst
Inflammations
Meniscus
Cortical bone
High
“White”
MRI Angiography
AV malformations
T1 orT2

67. Would you please arrange MRI in T2 for
RT & LT Temporomandibular joints
[TMJ] In Open and closed positions
[Sagittal view]for proper detection of the
position of the articular disc.
Axial Coronal