MRI magnetic resonance in head and neck

1. Prof. Moh. Ekram
Professor
of Oral Radiology
Faculty of Oral and Dental Medicine
Cairo University
Magnetic Resonance Imaging MRI

2. It is a technique which is completely different than
conventional radiography and computed
tomography as no ionizing radiation is used.
It does not depend on differences in electron
density (as CT and conventional radiography) but
on proton density, proton motion and tissue
magnetic relaxation characteristics.
Magnetic Resonance Imaging MRI

3. Proton Alignment
Normally protons are
aligned in a random
fashion.
When they are exposed
to a strong magnetic field
they align themselves
along poles of the field.
Protons

4. Proton Alignment
Normally protons are
aligned in a random
fashion.
Protons

5. Proton + Magnetic Field
When they are exposed to a strong magnetic field
they align themselves along poles of the field.

6. If a radiofrequency source is applied, the aligned
Nuclei will absorb energy and begin to resonate.
Proton + Radiofrequency source

7. If the original radiofrequency source is removed, the
nuclei will return to their original state giving off the energy they
absorbed by emitting a second radiofrequency signal
Radiofraquency
Source is off
Secondradiofrequencysignal
Proton + Radiofrequency source is Off

8. If the original radiofrequency source is removed, the
nuclei will return to their original state giving off the energy they
absorbed by emitting a second radiofrequency signal
Secondradiofrequencysignal

9. Protons of the body
(Hydrogen Nuclei) are
normally arranged
in a random state .
Application of a magnetic field
will cause the hydrogen nuclei
to align themselves along the
poles of the field.

10. If a radiofrequency source is applied, the aligned
Nuclei will absorb energy and begin to resonate.

11. If the original radiofrequency source is removed, the
nuclei will return to their original state giving off the energy
they absorbed by emitting a second radiofrequency signal

12. The steps of an MR
examination can be
described quite simply :
The patient is placed in a magnet.
A radiowave is sent in.
The radiowave is turned off.
The patient emits a signal.
The signal is received by a
sensor and conveyed to a
computer for reconstruction
of the picture (image)
General overview of MRI

13. The steps of an MR examination
in more details :
The patient is placed in a large,
extremely powerful magnet.
The magnetic field temporarily
changes the the alignment and
orientation of the protons in the
patient’s body.
Radiofrequency waves are applied to
the realigned protons. This
radiofrequency energy is absorbed.
Generation of MRI

14. The radiofrequency waves are
turned off.
The protons release the absorbed
energy in the form of signals.
The signal is received by a sensor,
and the information is transmitted
to a computer.
The information is processed and
the image is generated.
Generation of MRI (CON)

15. MRI system (open system)

16. Scope of MRI
MRI measures proton density (Hydrogen nuclei in
water).
70 % of the human body is water, of which proton
is the major component.
Therefore, NRI is better for visualizing soft tissues
(lot of water) and not as good for visualizing bone
(very little water).

17. Scope of MRI
MRI measures proton density
(Hydrogen nuclei in water).
70 % of the human body is
water, of which proton is the
major component.
Therefore, NRI is better for
visualizing soft tissues (lot of
water) and not as good for
visualizing bone (very little
water).
H2O

18. Scope of MRI (con)
Soft tissues show as
white area or Strong
signal intensity (many
water molecules).
Hard tissues show as
black area or weak signal
intensity (few water
molecules). Antral Carcinoma

19. Main Indications
of MRI

20. Investigation of the TMJ
Investigation of the TMJ to show both the
bony and soft tissue components of the
joint including the disc position.
Indications
Confirmation of internal derangement.
Pre-surgical evaluation.
Post-surgical evaluation.
Assessment of soft tissue components
of the joint.

21. Sections of MRI for examination of
the TMJ
Sagittal Coronal
M.Ekram
Oblique sagittal oblique coronal

22. MRI
CoronalSagittal
Closed mouth view
M.Ekram

23. Closed
Open
MRI of the TMJ
M.Ekram

24. Magnetic Resonance Imaging MRI
Advantages
Non-invasive.
Allows direct visualization of the disc.
Demonstrates the position and
morphology of disc.
Demonstrates the associating
inflammatory changes.
Dynamic.
M.Ekram

25. Magnetic Resonance Imaging MRI
Disadvantages
Decreased bone detail.
Perforation ?
M.Ekram

26. Tumor Staging
Evaluation of the site, size, and extent of
all soft tissue tumors and tumor like
lesions involving all areas including :
The salivary glands.
The sinuses.
The maxilla and mandible.

27. Sections
(Planes)
Of
The Head
(Cuts)
M.Ekram

28. Axial
Sagittal
Coronal
Sections (cuts) In MRI

29. Parotid malignancy extended
To the posterior belly of the
Digastric muscle T1

30. Carcinoma of the maxillary sinus the inflammatory disease
Is of high signal while the tumor is relatively of low signal.

31. Infected cyst of the maxilla

32. Magnetic Resonance Imaging MRI
Advantages
No ionizing radiation is used.
No adverse effects have yet been
demonstrated.
The possibility of image manipulation.
Excellent differentiation between different soft
tissue is possible and between normal and
abnormal tissues.
High resolution images can be reconstructed in
all planes (using 3d volume technique).
M.Ekram

33. Magnetic Resonance Imaging MRI
Disadvantages
Expensive.
Requires very expensive equipment.
Limited availability
Equipment tends to be claustrophobic and
noisy.
Of very little value for examination of bone.
M.Ekram

34. Magnetic Resonance Imaging MRI
Disadvantages (con)
Lengthy imaging procedure thus demanding
on the patient
Metallic objects (e.g endotracheal tubes) has
to be replaced by non-ferromagnetic
alternatives.
Contraindicated in patients with certain types
of surgical clips, cardiac pacemakers,
cochlear implants and in the first trimaster of
pregnancy.
M.Ekram

41. Normal parotid glands

42. Carcinoma max
sinus T1

43. Carcinoma max
sinus T2

44. A-V malformation

45. Magnetic Resonance Imaging in
examination of maxillofacial lesions

46. DERMOID PT DERMOID I.O
Extra-oral photograph showing: bulging submandibular area .
Intra – oral photograph showing irregularly resorped alveolar ridge, pus
oozing, and bulging floor of the mouth.
Chronic Suppurative Tuberculous
Osteomyelitis with Dermoid cyst

47. Panoramic radiograph showing bilateral sever irregular mandibular bone
destruction and abnormal bone rarefaction of right maxillary canine-
premolar area with loss of the normally corticated maxillary sinus floor of
the same side.

48. Coronal CT scans after l.V. contrast injection, showing:
Irregularly shaped lytic bony lesion involving the mandiblar body and maxillary
alveolar process causing medullary destruction, erosion and thinning of both
cortical plates with associated detached dense bony fragments representing
sequestration.

49. Incidentally there is a large midline cystic lesion at the level of the floor of
the mouth representing unrelated developmental dermoid cyst (double
arrow).

50. Axial TI- weighted MR images of the mandible injection of contrast medium
showing bilateral mandibular focal destructive bony lesion.
Before injection of contrast
agent
After injection of contrast
agent

51. Axial and coronal T2-weighted MR image of the mandible
showing the bilateral destructive lesion as focal areas of bright marrow
alteration with thinning and partial destruction of the normal dark cortical
plates (black arrows).
We can observe the dermoid cyst with a high signal intensity.
DC
DC

52. Coronal T1- weighted MR images before and after I.V. injection of contrast
agent showing relatively high signal intensity of the right side of the destructive
mandibular lesion.
We can observe the dermoid cyst with a high signal intensity.
After injection of contrast
agent
Before injection of contrast
agent
DCDC

53. Infected Odontogenic Keratocyst
An extra-oral photograph showing facial asymmetry of the
mandibular body more prominent on the right side.
An intra-oral photograph showing bone expansion of the
mandibular body with male alignment of the related teeth.

54. A well defined rafiolucency with scalloped border and interrupted radioopaque
margin involving the whole mandibular body.

55. Intra-oral periapical radiographs showing loss of lamina dura of mandibular
teeth in the area involved by the lesion.
Intra-oral occlusal radiograph showing expansion of the labial and lingual
cortical plates.

56. Markedly expansile cystic lesion involving the mandibular body with
relative thinning (white arrow).
Bone windowST window
Coronal CT scans

57. Bone windowST window
Axial CT scans
detached dense bony fragment

58. Axial T1-weighted MR image before and after I.V. injection
showing hypointense signal of the mandibular cystic lesion with
notable thinning and focal destruction of the labial cortical plate at
the midline area.

59. Axial T2-weighted MR image showing: intensely bright signal
of the mandibular cystic lesion replacing the normal
medullary signal.

60. Axial and coronal CT scans, bone window images after I.V. contrast
injection showing expansile unilocular cystic lesion involving the right maxilla
(double arrow). The lesion has a sclerotic margin (white arrowhead) .The lesion
causes slight upward displacement of the right nasal floor.

61. Coronal and axial CT scans, soft tissue window images after I.V. contrast
injection showing homogeneous density of the central core of the lesion (double
arrow) .

62. coronal T1-weighted MR images after I.V. contrast injection showing the
intermediate signal intensety of the expansile maxillary lesion of having a uniform
outer margin of intermediate to hypointense signal. It shows a uniform peripheral
enhancement.

63. Axial and coronal T2-weighted MR images showing intensely bright signal of
the lesion (double arrow) with peripheral hypointense signal.

64. Magnetic Resonance
Imaging of The TMJ

65. Mandibular
component
TMJ AnatomyTemporal
component

66. Articular fossa
Ear
Articular
eminence
Normal Anatomy
Sagittal

67. Condyle
Disk
Articular fossa
Normal Anatomy
Coronal

68. AB = Anterior band of miniscus
PB = Posterior band of miniscus
IZ = Intermediate zone of miniscus
SPT= Attachment to the superior
head of the lateral pterygoid
muscle
IPT = Attachment to the inferior
head of the lateral pterygoid
muscle
el. att = Elastic attachment to fossa
Fib.att = Fibrous attachment to fossa
BLZ = Bilaminar zone
Interarticular disc and
posterior attachement
Bow tie

69. AB = Anterior band of miniscus
PB = Posterior band of miniscus
IZ = Intermediate zone of miniscus
SPT= Attachment to the superior
head of the lateral pterygoid
muscle
IPT = Attachment to the inferior
head of the lateral pterygoid
muscle
el. att = Elastic attachment to fossa
Fib.att = Fibrous attachment to fossa
BLZ = Bilaminar zone
The Articular Disc
The articular disc looks like (School’s boy or Jockey's cap)
which overlies the condylar head.
Interarticular disc and posterior attachement

70. MRI of the TMJ

71. SAGITTAL
CORONAL
MRI of the TMJ
Axial

72. Paramedial oblique sagittal
Sagittal Sections
Less artifacts !!

73. True frontal oblique frontal
Frontal Sections
(coronal)
Uncorrected !!

74. • The shape of the condyle varies
From different angles.
• Rarely both sides are symmetrical
What is meant by
Corrected & non-corrected views ?

75. What is meant by
Corrected & non-corrected views ?
Shooting considering
The axis of the condyle
Corrected view
Shooting without considering
The axis of the condyle
non-corrected view

76. Only layers are enough !!!
Medial Center Late
Posterior border of the
assencing ramus
Lateral Pterygoid
M
Disc

77. Normal disc position
Sagittal

78. Normal disc position
Frontal- Coronal

79. 1. Pars anterior
2. Pars media
3. Condyle
1,2. Disc
3. Condyle

80. Common TMJ Abnormalities and Disorders
(TMD)

81. Internal derangement
Of the TMJ

82. Internal Derangement of the TMJ
It is an abnormal relationship of the articular disc to the
condyle which interferes with the smooth action of the
joint .
Internal derangement is characterized by clicking of the
joint due to a disc displacement or alternatively a
mechanical obstruction to mouth opening.

83. Displacement of the articular disc from it’s original
position.
Medial PosteriorAneriorLateral
Disc displacement

84. Anterior Disk Displacement
The most common form of disc displacemen is :

85. Types of Anterior Disc Displacement
I. Anterior disc displacement with reduction
ADDR
(Reciprocal clicking of the joint)
II. Anterior disc displacement without reduction
ADD
(Anterior disc dislocation , locked jaw)

86. JAW OPENING CYCLE
Normal position ADDR ADD

87. Normal disc position
Sagittal

88. Normal disc position
Frontal- Coronal

89. Normal joint arrangement
10
closed
12
open
Maximum opening

90. Anterior Disc Displacement
with Reduction
(Reciprocal Clicking)
ADDR
Reciprocal Clicking is a term is used to
describe patients
with opening and closing clicks.

91. ADD With Reduction
The disc is displaced while the mouth is in the closed position
but returns to the normal position relative to the condyle with jaw
opening.
ClosedOpen

92. Closed View Open View
Anterior Disc Displacement With Reduction (ADDR)
The disc is displaced while the mouth is in the closed position
but returns to the normal position relative to the condyle with
jaw opening.

93. ADD without reduction
ClosedOpen
Anterior Disc Displacement Without Reduction (Locked
jaw)

94. Anterior Disc Displacement Without Reduction (ADD)
The disc is displaced in both the closed and open positions.
Closed View Open View

95. Important Remarks
“A joint that clicks is not
locked , and a joint that locks
does not click “.

96. Some patients may give a clear documented description of the clinical
progression of their internal derangement
 Clicking with pain
 Less clicking
 more pain , occasional Locking
 Persistent pain and locking
 Painless clicking

97. JAW OPENING CYCLE
Normal position ADDR ADD

98. Magnetic Resonance Imaging MRI
Indications
Confirmation of internal derangement
(The best imaging method).
Pre-surgical evaluation.
Post-surgical evaluation.
Demonstrates soft tissue components of the joint.

99. Magnetic Resonance Imaging MRI
Advantages
Non-invasive.
No ionizing radiation.
Direct visualization of disc.
Position and morphology of disc.
Associating inflammatory changes.
Dynamic.

100. Magnetic Resonance Imaging MRI
Disadvantages
Expensive.
Limited availability
Requires expensive equipment.
Lengthy imaging procedure
Decreased bone detail.
Perforation ?
Has many contraindications.

101. Magnetic Resonance Imaging MRI
Disadvantages
Expensive.
Limited availability
Requires expensive equipment.
Lengthy imaging procedure
Decreased bone detail.
Perforation ?
Has many contraindications.

102. Magnetic Resonance Applications
Imaging in examination of maxillofacial
lesions

103. DERMOID PT DERMOID I.O
Extra-oral photograph showing: bulging submandibular area .
Intra – oral photograph showing irregularly resorped alveolar ridge, pus
oozing, and bulging floor of the mouth.
Chronic Suppurative Tuberculous
Osteomyelitis with Dermoid cyst

104. Panoramic radiograph showing bilateral sever irregular mandibular bone
destruction and abnormal bone rarefaction of right maxillary canine-
premolar area with loss of the normally corticated maxillary sinus floor of
the same side.

105. Coronal CT scans after l.V. contrast injection, showing:
Irregularly shaped lytic bony lesion involving the mandiblar body and maxillary
alveolar process causing medullary destruction, erosion and thinning of both
cortical plates with associated detached dense bony fragments representing
sequestration.

106. Incidentally there is a large midline cystic lesion at the level of the floor of
the mouth representing unrelated developmental dermoid cyst (double
arrow).

107. Axial TI- weighted MR images of the mandible injection of contrast medium
showing bilateral mandibular focal destructive bony lesion.
Before injection of contrast
agent
After injection of contrast
agent

108. Axial and coronal T2-weighted MR image of the mandible
showing the bilateral destructive lesion as focal areas of bright marrow
alteration with thinning and partial destruction of the normal dark cortical
plates (black arrows).
We can observe the dermoid cyst with a high signal intensity.
DC
DC

109. Coronal T1- weighted MR images before and after I.V. injection of contrast
agent showing relatively high signal intensity of the right side of the destructive
mandibular lesion.
We can observe the dermoid cyst with a high signal intensity.
After injection of contrast
agent
Before injection of contrast
agent
DCDC

110. Infected Odontogenic Keratocyst
An extra-oral photograph showing facial asymmetry of the
mandibular body more prominent on the right side.
An intra-oral photograph showing bone expansion of the
mandibular body with male alignment of the related teeth.

111. A well defined rafiolucency with scalloped border and interrupted radioopaque
margin involving the whole mandibular body.

112. Intra-oral periapical radiographs showing loss of lamina dura of mandibular
teeth in the area involved by the lesion.
Intra-oral occlusal radiograph showing expansion of the labial and lingual
cortical plates.

113. Markedly expansile cystic lesion involving the mandibular body with
relative thinning (white arrow).
Bone windowST window
Coronal CT scans

114. Bone windowST window
Axial CT scans
detached dense bony fragment

115. Axial T1-weighted MR image before and after I.V. injection
showing hypointense signal of the mandibular cystic lesion with
notable thinning and focal destruction of the labial cortical plate at
the midline area.

116. Axial T2-weighted MR image showing: intensely bright signal
of the mandibular cystic lesion replacing the normal
medullary signal.

117. Inflammatory Periapical Cyst
Intraoral photographic picture showing hard expansial palatal swelling of
the right side.

118. Infected Inflammatory Periapical Cyst
Occlusal radiograph showing well-defined radiolucent area occupying
most of the right side of the palate. The lesion is surrounded with
radioopaque margin which is interrupted at the anterior area.

119. Panoramic radiograph showing well-defined radiolucent area related to the
right maxillary anteriors and premolars

120. Axial and coronal CT scans, bone window images after I.V. contrast
injection showing expansile unilocular cystic lesion involving the right maxilla
(double arrow). The lesion has a sclerotic margin (white arrowhead) .The lesion
causes slight upward displacement of the right nasal floor.

121. Coronal and axial CT scans, soft tissue window images after I.V. contrast
injection showing homogeneous density of the central core of the lesion (double
arrow) .

122. coronal T1-weighted MR images after I.V. contrast injection showing the
intermediate signal intensety of the expansile maxillary lesion of having a uniform
outer margin of intermediate to hypointense signal. It shows a uniform peripheral
enhancement.

123. Axial and coronal T2-weighted MR images showing intensely bright signal of
the lesion (double arrow) with peripheral hypointense signal.

124. Magnetic Resonance
Imaging of The TMJ

125. Mandibular
component
TMJ AnatomyTemporal
component

126. Articular fossa
Ear
Articular
eminence
Normal Anatomy
Sagittal

127. Condyle
Disk
Articular fossa
Normal Anatomy
Coronal

128. AB = Anterior band of miniscus
PB = Posterior band of miniscus
IZ = Intermediate zone of miniscus
SPT= Attachment to the superior
head of the lateral pterygoid
muscle
IPT = Attachment to the inferior
head of the lateral pterygoid
muscle
el. att = Elastic attachment to fossa
Fib.att = Fibrous attachment to fossa
BLZ = Bilaminar zone
Interarticular disc and
posterior attachement
Bow tie

129. AB = Anterior band of miniscus
PB = Posterior band of miniscus
IZ = Intermediate zone of miniscus
SPT= Attachment to the superior
head of the lateral pterygoid
muscle
IPT = Attachment to the inferior
head of the lateral pterygoid
muscle
el. att = Elastic attachment to fossa
Fib.att = Fibrous attachment to fossa
BLZ = Bilaminar zone
The Articular Disc
The articular disc looks like (School’s boy or Jockey's cap)
which overlies the condylar head.
Interarticular disc and posterior attachement

130. MRI of the TMJ

131. SAGITTAL
CORONAL
MRI of the TMJ
Axial

132. Paramedial oblique sagittal
Sagittal Sections
Less artifacts !!

133. True frontal oblique frontal
Frontal Sections
(coronal)
Uncorrected !!

134. • The shape of the condyle varies
From different angles.
• Rarely both sides are symmetrical
What is meant by
Corrected & non-corrected views ?

135. What is meant by
Corrected & non-corrected views ?
Shooting considering
The axis of the condyle
Corrected view
Shooting without considering
The axis of the condyle
non-corrected view

136. Only layers are enough !!!
Medial Center Late
Posterior border of the
assencing ramus
Lateral Pterygoid
M
Disc

137. Normal disc position
Sagittal

138. Normal disc position
Frontal- Coronal

139. 1. Pars anterior
2. Pars media
3. Condyle
1,2. Disc
3. Condyle

140. Common TMJ Abnormalities and Disorders
(TMD)

141. Internal derangement
Of the TMJ

142. Internal Derangement of the TMJ
It is an abnormal relationship of the articular disc to the
condyle which interferes with the smooth action of the
joint .
Internal derangement is characterized by clicking of the
joint due to a disc displacement or alternatively a
mechanical obstruction to mouth opening.

143. Displacement of the articular disc from it’s original
position.
Medial PosteriorAneriorLateral
Disc displacement

144. Anterior Disk Displacement
The most common form of disc displacemen is :

145. Types of Anterior Disc Displacement
I. Anterior disc displacement with reduction
ADDR
(Reciprocal clicking of the joint)
II. Anterior disc displacement without reduction
ADD
(Anterior disc dislocation , locked jaw)

146. JAW OPENING CYCLE
Normal position ADDR ADD

147. Normal disc position
Sagittal

148. Normal disc position
Frontal- Coronal

149. Normal joint arrangement
10
closed
12
open
Maximum opening

150. Anterior Disc Displacement
with Reduction
(Reciprocal Clicking)
ADDR
Reciprocal Clicking is a term is used to
describe patients
with opening and closing clicks.

151. ADD With Reduction
The disc is displaced while the mouth is in the closed position
but returns to the normal position relative to the condyle with jaw
opening.
ClosedOpen

152. Closed View Open View
Anterior Disc Displacement With Reduction (ADDR)
The disc is displaced while the mouth is in the closed position
but returns to the normal position relative to the condyle with
jaw opening.

153. ADD without reduction
ClosedOpen
Anterior Disc Displacement Without Reduction (Locked
jaw)

154. Anterior Disc Displacement Without Reduction (ADD)
The disc is displaced in both the closed and open positions.
Closed View Open View

155. Important Remarks
“A joint that clicks is not
locked , and a joint that locks
does not click “.

156. Some patients may give a clear documented description of the clinical
progression of their internal derangement
 Clicking with pain
 Less clicking
 more pain , occasional Locking
 Persistent pain and locking
 Painless clicking

157. JAW OPENING CYCLE
Normal position ADDR ADD

158. Magnetic Resonance Imaging MRI
Indications
Confirmation of internal derangement
(The best imaging method).
Pre-surgical evaluation.
Post-surgical evaluation.
Demonstrates soft tissue components of the joint.

159. Magnetic Resonance Imaging MRI
Advantages
Non-invasive.
No ionizing radiation.
Direct visualization of disc.
Position and morphology of disc.
Associating inflammatory changes.
Dynamic.

160. Magnetic Resonance Imaging MRI
Disadvantages
Expensive.
Limited availability
Requires expensive equipment.
Lengthy imaging procedure
Decreased bone detail.
Perforation ?
Has many contraindications.

161. Thank youQuestions ?