The document discusses the anatomy and radiographic evaluation of the skull, describing the bones that make up the cranial vault and facial skeleton, landmarks and sutures, skull projections including PA, lateral, Towne's view and submentovertical views, and anatomical structures visible on each view such as sinuses, foramina and cervical spine. Standard exposure factors are provided for the various skull radiographic projections.

1. Roentgenology of skull
DR AKSHAY GURSALE
MGM MEDICAL COLLEGE , NAVI MUMBAI
DEPT. OF RADIOLOGY AND IMAGING

2. 2 types of Skull bones
8 Cranial -form protective housing
of brain (cranial vault)
-provides structure, shape & support
for face
14 Facial -protective housing for upper ends of
respiratory & digestive tracts
- with cranial-forms eye sockets

4. The 8 Cranial Bones are:
• 1 Frontal
• 2 Parietal
• 1 Occipital
• 1 Ethmoid
• 1 Sphenoid
• 2 Temporal

5. Top of skull = skull cap
= Calvarium
• It is made up of 4
bones
• Frontal
• L & R Parietal
• Occipital

6. Frontal bone

7. Anterior
Frontal
Inferior

8. X RAY VIEW OF FRONTAL BONE

9. 2 parietal bones

10. XRAY VIEW OF PARIETAL BONE

11. Occipital
Floor of Cranium

12. The Floor of the Cranium is made of 4 bones
(The four on the floor!)
• The Ethmoid
• The Sphenoid
• Left & Right
Temporal bones

13. 1 Ethmoid Bone

14. 1 Sphenoid
bone

15. 2 Temporal bones

17. Temporal Bones
PETROUS RIDGE
LATERAL
AP

18. ACTUAL VIEW OF THE TEMPORAL BONE IN DIFFERENT ANGLES

19. INTERNAL ASPECT

20. INFERIOR ASPECT

21. ANATOMICAL VIEW OF BASE OF SKULL FROW ABOVE

22. INFERIOR VIEW OF THE SKULL

26. Few terms in base of skull
• Platybasia
– Flattening of the base of the skull
– Increase in the basal angle between the base of clivus and
anterior cranial fossa
• Basilar invagination
– Elevation of floor of posterior fossa due to acquired
condition on softening of base of skull like Paget’s
disease, rickets , osteomalacia etc
• Basilar impression
– Elevation in floor of posterior fossa as a congenital anomaly
like atlanto-occipital fusion , klippel feil syndrome etc.
foramen magnum may be abnormal in size or shape

27. There are 14 Facial Bones
• 2 maxillary bones
• 2 nasal
• 2 lacrimal
• 2 Zygoma (malar)
• 2 palatine
• 2 inferior nasal conchae
• 1 vomer
• 1 mandible

28. 2 Maxillary bones

29. 2
nasal bones
2
lacrimal bones

30. 2 Zygomas

31. 2 Palatine bones

32. 2 inferior nasal conchae

33. 1 Vomer

34. 1 Mandible

35. PNS WATERS VIEW FOR ALL FACIAL BONES

37. NEONATAL SKULL ANATOMY

38. The developing skull has three component
origins:
•Condrocranium (base of skull / braincase)
•Dermatocranium (flat bones of skull)
•Splanchnocranium (bones derived from
gill arch elements)

39. Mode of Germ Layer
Formation Origin
Condrocranium Endochondral Mesoderm
Dermatocranium Dermal Neural Crest
Splanchnocranium Endochondral Neural Crest

40. orbit II/
Ethmoid
Sphenoid
Petrous temporal
Basioccipital

42. Flat bones of skull: DERMATOCRANIUM
(These and others.)

46. What are fontanels?
Six areas of incomplete ossification in a
newborn

47. Sphenoidal
fontanel (pterion)
Mastoid
fontanel
(asterion)

48. At what age do the fontanels close?
• Posterior and
sphenoidal fontanels
close during first 1-3
months after birth
• Anterior and
mastoid fontanels
close during 2nd year
of life

49. Fontanels
• Soft spots • Most prominent are the
• Present at birth anterior and posterior
• Unossified connective fontanels
tissue • Located on the anterior
• Where three or more and posterior ends of
bones are joint the sagittal suture
• Six Fontanels
• Gradually replaced with
bone
• Allow for skull
compression during
birth

50. Fontanels
• Articulation between the • Anterolateral (sphenoid)
frontal and both parietal fontanel is the pterion
bones at the anterior
end of the sagittal • Posterolateral fontanel
suture is the bregma is the asterion
• Articulation between the
occipital bone and both
parietal bones at the
posterior end is the
lambda

52. Skull Morphology
• Mesocephalic: Average shaped
head, the petrous ridges lie at a 47
degree angle with the MSP
• Brachycephalic: Short, broad, shallow
head. Petrous ridges form a 54 degree
angle with the MSP
• Dolichocephalic: Long, narrow, deep
head. Petrous ridges form a 40 degree
angle with the MSP

53. Skull Morphology
Mesocephalic Brachycephalic Dolichocephalic

54. All skull positions are based on 3 factors
• Rotation
• Tilt
• Flexion-
Extension

55. 3 types of Skull Position change
• 1st type -
• Rotation -your head is
rotating on an axis-your
neck
• The “NO” position

56. 2nd type of skull position change
• Flexion-extension
• Also called “Yes”
position

57. 3rd type of skull position change
• Tilt
• Or “Maybe” position

58. Average Skull

60. Lines/Landmarks/Planes

62. Radiographic Baselines
Glabellomeatal
A
Orbitomeatal B
Infraorbitomeatal C
Acanthiomeatal D
Mentomeatal E

63. LANDMARKS IN SKULL XRAY

64. SAME LINES SHOWN ON A LATERAL XRAY FILM

65. The standard projections taken for skull
are as follows
– Lateral view
– PA(Postero anterior) view
– Towne’s view
– Basal view(submentovertical view)
• Other special views include the following
– optic foramen view
– Sinuses
– Petrous bones
– Coned pituitary fossa

66. P-A Skull
• Measure: A-P at the
Glabella
• Protection: Full coat
apron with lead to back
or half apron draped over
back of chair.
• No tube angle
• Film: 10” x 12” regular
I.D. down (portrait)
66

67. P-A Skull
• Patient seated or standing facing the Bucky.
• Nose and forehead touching the Bucky to get
the canthomeatal line perpendicular to film.
• Horizontal CR: exit through the glabella.
• Vertical CR: mid-sagittal plane
• Center film to horizontal CR
• Collimation: slightly less than film size.
• Breathing Instructions: Suspended
respiration
67

68. P-A Skull
• Make exposure and let
patient relax.
• Note: If the patient is
done seated, place Bucky
tray in the lower Bucky
slot. This will allow the
patient to get their legs
under the Bucky.
68

69. P-A Skull Film
• The entire skull should
be on the film.
• There should be no
rotation.
• The petrous ridges will
be superimposed with
the orbits.
• To clear the
ridges, the Caldwell
view can be taken.
69

70. SINUSES
PA view
8
1. Nasal Septum
2. Frontal Sinus
3. Maxillary Sinus
10 4. Ethmoid Sinus
2 5. Inferior Turbinate
6. Odontoid process
7. Superior orbital fissure
7
4 8. Sagittal suture
9 9. Superior orbital fissure
10. Coronal suture
12 11. Petrous ridge
12. Sphenoid ridge
14 13. Mastoid process
3
14. Innominate line
11 1 15. Hard palate
5
13
15
6

72. Exposure factors
• 80 Kv
•Fine focus
•Use grid
•Cassette size 24*30 cms
•Fixed focus 100 cms
•Central ray 0 degrees
•OMBL 0 degrees

73. Chamberlain-Townes
• The Townes Projection is
part of a routine skull
series.
• The tube is angled to
throw the anterior part of
the skull away from the
occipital region of the
skull.
73

74. Chamberlain-Townes
• Measure: A-P at Glabella
• Protection: Half apron
or Coat Apron
• SID: 40” Bucky
• Tube angle: 35 degrees
Caudal
• Film: 10” x 12“ regular
I.D. Down (portrait)
74

75. Chamberlain-Townes
• Patient is seated facing the tube.The chin is tucked
into the chest until the canthomeatal line is
perpendicular to film.
• Horizontal CR: Through the EAM. The Horizontal CR
will usually pass through the hair line.
• Vertical CR: mid-sagittal
• Film centered to horizontal CR
• Collimation: slightly less than film size or soft tissue
of skull
75

76. Chamberlain-Townes
• Breathing Instructions: Suspended respiration
• Make exposure
• Let patient breathe and relax
76

77. Chamberlain-Townes Film
• The entire skull and
especially the occipital
region of the skull
must be on the film.
• Structure seen include
the foramen
magnum, petrous
ridges, IAC’s and TM
Joints
• No rotation of skull
77

79. SKULL
11 Townes view
1 1. Parietal bone
1 2. Lambdoid suture
3. Foramen magnum
4. Petrous temporal bone
5. Mandible
6. Mastoid air cells
7. Transverse sinus
2 8. Sphenoid sinus
9. Greater wing of
3 sphenoid
10. Temporal tubercle
11. Superior sagttal sinus
7
4
9
6 8
10
5

80. • Exposure factors
– 85 Kv
– Fine focus
– With grid
– Cassette 24*30
– Fixed focus distance 100 cms
– Central ray caudal 30 degrees
– OMBL 0 degrees

81. Skull Lateral
• Measure: Lateral at EAM
• Protection: Full coat
apron or half apron
draped over back of chair
• Tube angle: none but
may be angled parallel to
interpupillary line.
• Film: 12” x 10” I.D. to
face (landscape)
81

82. Skull Lateral
• Patient seated of standing facing the Bucky. Rotate
the body into an oblique position.
• Turn skull so the affected side is next to the Bucky.
• The interpupillary line must be perpendicular to film
and tube.
• Mid sagittal plane parallel to the film.
82

83. Skull Lateral
• Horizontal CR:
3/4”superior to EAM
• Vertical CR: 3/4”
anterior to EAM or mid
skull
• Center film to
horizontal CR.
• Collimation: slightly
less than film size
• Breathing
Instructions:
Suspended respiration
• Make exposure and
let patient relax.
83

84. Skull Lateral Film
• Entire skull must be on
the film.
• There should be no
rotation of the
skull, orbits and
mandible ramus
superimposed.
• The facial bones are
sinuses will be dark
(over exposed).
• Usually both lateral
views are taken.
84

85. 1. Frontal Sinus
2. Maxillary Sinus
3. Ethmoid Sinus
4. Spenoid Sinus
11 5. Sella Turcica
6. Occipital Bone
1 7. Mastoid Air Cells
8. Floor of posterior fossa
9. Anterior arch of C-1
10. Mandible
3 11.Coronal Suture
5
7
2
4
6
9 8
10
Lateral Sinus & Skull

87. • Exposure Factors
– 90 Kv
– Fine focus
– With grid
– Cassette 24*30 cms
– Fixed focus distance 100 cms
– central ray 0 degrees
– OMBL 90 degrees cranially

88. Base Posterior Skull
(SUBMENTOVERTICAL VIEW)
• Routine skull view that
can be used to evaluate
the upper cervical spine.
• Provides an axial view of
C-1 and C-2 as well as
the foramen magnum.
88

89. Submentovertical Skull view
• Measure: A-P at Glabella
• Protection: Half apron
• Tube Angle: None but if
patient cannot extend
head back far enough to
get inferior orbital meatal
line perpendicular to
horizontal CR tube angle
may be needed.
89

90. Submentovertical Skull view
• Film Size: 10” x 12” regular I.D. down (Portrait)
• Patient is seated in a reclining chair. The chair is
placed about 6” to 10” from Bucky.
• Patient is asked to extend neck back until inferior
orbital meatal line is parallel to film with top of skull
touching the Bucky.
• Horizontal CR: EAM
• Vertical CR: mid-sagittal
• Center film to horizontal CR
• Collimation: slightly less than film size or skin of
skull
• Breathing Instructions: suspended respiration
• Make exposure
90

91. • Exposure factors
– 90 Kv
– Fine focus distance
– With grid
– Casette 24*30 cms
– Fixed focus distance 100 cms
– Central ray 0 degrees
– OMBL 90 degrees cranially

92. Submentovertical Skull Films
• This basilar view of
skull has the
patient’s head not
extended back far
enough. The
mandible and frontal
skull should be
superimposed.
92

93. Submentovertical Skull Films
• If the upper cervical
spine or mastoid
processes and
internal auditory
canals are the areas
of interest, it is
appropriate to cone
down to this area.
93

94. 1. Lat. & Med. ptyergoid
plate
2. Ethmoid Sinus
6 3. Odontoid Process
4. Sphenoid Sinus
5. Foramen ovale
2 6. Maxillary Sinus
7. Mastoid air cells
8. Ant arch of C-1
9. Margin of foramen
magnum
10. Ext. auditory canal
11. Foramen spinosum
12. Carotid canal
1 13. Cervical spine
5 4
11 10
12 8
3
7
9
13
BASE OF SKULL

95. Schullers Protection
• Measure: lateral at EAM
• Protection: Lead apron
• SID: 40” Bucky
• Tube angle: 25 degrees
caudal
• Film size: 8” x 10” I.D.
up (portrait)
95

96. Schullers Protection for TMJ
• Patient is seated facing
the Bucky. Head is
turned to place the
affected TMJ next to
Bucky.
• Skull should be in a true
lateral position. Align
the TMJ to the center
line of the Bucky.
• The vertical CR should
be aligned with TMJ
away from film.
96

97. Schullers Protection for TMJ
• Change cassettes to a
new 8” x 10”
• Ask patient to open
mouth as far as
possible.
• Recheck positioning.
• Breathing
Instructions: With
mouth wide open, don’t
breathe move or
swallow.
• Make exposure and let
patient relax.
97

98. Schullers Protection for TMJ
• If the affected TMJ and
the side away from the
Bucky is aligned with
the Center of the Bucky
and Vertical CR, the
skull will be in the true
lateral position.
• The horizontal CR is
aligned with the
Affected TMJ (closest
to film).
98

99. Schullers Protection for TMJ
• Center film to
horizontal CR.
• Collimation: 5” x 5”
• Breathing
instructions: Keep
mouth closed and don’t
breathe move or
swallow.
• Make exposure.
• Let patient breathe
but remain in the
position.
99

100. Schullers Protection for TMJ
• Open and closed mouth
view are taken of both
TM joints.
• The TMJ closest to the
Bucky will be the one
seen at the center or top
of the film.
• Accurate positioning is
essential to being able to
compare joints.
100

101. MAGNIFIED XRAY SCHULLERS VIEW

102. Caldwell Sinus Projection
• Patient is seated facing
Bucky.
• Ask patient to place their
nose and forehead on
center line of Bucky.
• Check for rotation.
102

103. Caldwell Sinus Projection
• The Caldwell Projection
will have the petrous
ridges below the orbits.
• Positioning is exactly like
the P-A skull with the
exception of the use of a
15 degree caudal tube
angle to lower the
petrous ridges.
103

104. Caldwell Sinus Projection
• Measure: A-P at Glabella
• Protection: Coat apron
backwards or half apron
draped over back of
chair.
• SID: 40” Bucky
• Tube angle: 15 degrees
caudal
• Film: 8” x 10” Regular
I.D. Down (portrait)
104

105. Caldwell Sinus Projection
• Horizontal CR: exits
through the Glabella or
Nasion
• Vertical CR: mid-sagittal
• Center film to
horizontal CR
• Collimation: 6” or 7”
square.
• Breathing
Instructions:
Suspended Respiration
105

106. • EXPOSURE FACTORS
– 80 Kv
– Fine focus
– With grid
– Casette size 24*30 cm
– Fixed focus distance of 100 cm
– Central ray 20 degree caudal
– OMBL 0 degrees

107. Caldwell Sinus Projection Film
• This view will
provide a clear view
of the frontal and
ethmoid sinuses.
• The super orbital
rims can be
evaluated for
fracture when facial
bone are of interest.
107

108. SINUS
CALDWELL VIEW
FRONTAL SINUS
ORBIT
SPHENOID
BONE
INFERIOR
TURBINATE
MASTOID HARD PALATE
AIR CELLS
MANDIBLE

109. Waters Projection Sinus
• The most important view
for sinus problems or
injury involving the
maxilla or orbits.
• By taking the view
erect, fluid levels within
the maxillary sinuses can
be seen.
109

110. Waters Projection Sinus
• Measure: A-P at Glabella
• Protection: Half apron
over back of chair or coat
apron backwards
• SID: 40” Bucky
• No tube angle
• Film: 8” x 10” regular
I.D. Down (portrait)
110

111. Waters Projection Sinus
• Patient is seated facing
the Bucky. Get the chair
as close to the Bucky as
possible. Patient may
spread legs to get chair
as close as possible. May
also be taken standing.
• Mentomeatal line should
be perpendicular to film
with mouth closed.
111

112. Waters Projection Sinus
• The nose will be one to
two centimeters from
Bucky with chin resting
on Bucky.
• The mouth may be
opened to see the
sphenoid sinus. When
this is done, the
canthomeatal line should
be 35 to 40 degrees to
the Bucky.
112

113. Waters Projection Sinus
• Horizontal CR: exit
through the base of nose
or acantha.
• Vertical CR: mid-sagittal
• Center film to
horizontal CR
• Collimation: 6” or 7”
square
113

114. • Exposure factors
– 80 Kv
– Fine focus
– With grid
– Cassette 24*30 cms
– Fixed focus distance 100 cms
– Central ray 0 degrees
– OMBL 45 degrees cranially

115. Waters Projection Sinus Film
• This is an example of the
open mouth waters view.
• The facial bones and
sinuses should be on the
film.
• There should be no
rotation.
• The petrous ridges must
be below the floor of the
maxilla.
115

116. Waters Projection Sinus Film
• The facial bones and
sinuses should be on the
film.
• There should be no
rotation.
• The petrous ridges must
be below the floor of the
maxilla.
116

117. AP WATERS VIEW
SINUSES
1. Frontal sinus
1 2. Ethmoid Sinus
3. Nasal Septum (bony)
10
4. Zygomatical-Frontal Suture
5. Maxillary Sinus
6. Zygoma
2 7. Zygomatic Arch
8. Mandible
4 9. Inferior orbital margin
5 10. Left orbit
3
9 6
7
8

118. XRAY VIEW OF OPTIC FORAMINA

119. An example of normal Stenvers View

120. CONED PITUITARY FOSSA VIEW

121. INDICATIONS FOR EXTRAORAL RADIOGRAPH
Mid face series
• Water’s view
– For facial fractures
– Zygomatic arches, orbital rims and floors, nasal spine and
septum, coronoid process
– Frontal, maxillary and sphenoid sinuses
• PA view
– Progressive changes in mediolateral skull
– Orbital rim, frontal and ethmoid sinuses, nasal septum, nasal
fossa
• Submentovertex View
– For fracture of zygomatic arch
– Position and orientation of condyles, sphenoid
sinuses, curvature of mandible, lateral wall of maxillary
sinuses
– Skull foramina, medial and lateral pterygoid plates

122. • Lateral skull
– For head growth assesssment
– Anterior/posterior walls of frontal and maxillary
sinuses, nasopharyngeal soft tissue
– Paranasal sinuses and hard palate
Lower face series
• Panorex
– For viewing mandible and condyles
• Lateral oblique
– Mandibular body and ramus
• Towne’s
– Condyles, necks , rami and mandibular symphysis
– Occipital bone, foramen magnum, dorsum sellae and
petrous ridges

123. • Reverse Towne’s view
– Condylar neck , posterolateral wall of maxillary antrum
• Temporomandibular joint views
– Transpharyngeal projection
• For gross changes on condylar surfaces
– Transorbital projection
• Medial and lateral aspect of condyle, neck , eminence and zygomatic
arch
– Transcranial projection
• View the long axis of the condyle and relationship of condyle to the
fossa
– Panorex