Roentgenology of skull

DR AKSHAY GURSALEMGM MEDICAL COLLEGE , NAVI MUMBAIDEPT. OF RADIOLOGY AND IMAGING

-form protective housing of brain (cranial vault)

14 Facial

2 types of Skull bones

8 Cranial

-provides structure, shape & support for face-protective housing for upper ends of respiratory & digestive tracts- with cranial-forms eye sockets

The 8 Cranial Bones are:

• 1 Frontal

• 2 Parietal

• 1 Occipital

• 1 Ethmoid

• 1

Sphenoid

• 2

Temporal

Top of skull = skull cap = Calvarium

• It is made up of 4 bones

• Frontal • L & R Parietal • Occipital

Frontal bone

Frontal

Anterior

Inferior

X RAY VIEW OF FRONTAL BONE

2 parietal bones

XRAY VIEW OF PARIETAL BONE

Occipital

Floor of Cranium

The Floor of the Cranium is made of 4 bones

(The four on the floor!)

• The Ethmoid• The Sphenoid• Left & Right

Temporal bones

1 Ethmoid Bone

1 Sphenoid bone

2 Temporal bones

Temporal Bones

LATERAL

AP

PETROUS RIDGE

ACTUAL VIEW OF THE TEMPORAL BONE IN DIFFERENT ANGLES

INTERNAL ASPECT

INFERIOR ASPECT

ANATOMICAL VIEW OF BASE OF SKULL FROW ABOVE

INFERIOR VIEW OF THE SKULL

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

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

2 Maxillary bones

2 nasal bones

2 lacrimal bones

2 Zygomas

2 Palatine bones

2 inferior nasal conchae

1 Vomer

1 Mandible

PNS WATERS VIEW FOR ALL FACIAL BONES

NEONATAL SKULL ANATOMY

The developing skull has three component origins:

•Condrocranium (base of skull / braincase)

•Dermatocranium (flat bones of skull)

•Splanchnocranium (bones derived from gill arch elements)

Mode of Germ Layer Formation Origin

Condrocranium Endochondral Mesoderm

Dermatocranium Dermal Neural Crest

Splanchnocranium Endochondral Neural Crest

orbit II/

Ethmoid

Sphenoid

Petrous temporal

Basioccipital

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

What are fontanels?

Six areas of incomplete ossification in a newborn

Mastoidfontanel(asterion)

Sphenoidalfontanel (pterion)

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

Fontanels

• Soft spots• Present at birth• Unossified connective tissue• Where three or more bones are joint• Six Fontanels• Gradually replaced with bone• Allow for skull compression during birth

• Most prominent are the anterior and posterior fontanels

• Located on the anterior and posterior ends of the sagittal suture

Fontanels

• Articulation between the frontal and both parietal bones at the anterior end of the sagittal suture is the bregma

• Articulation between the occipital bone and both parietal bones at the posterior end is the lambda

• Anterolateral (sphenoid) fontanel is the pterion

• Posterolateral fontanel is the asterion

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

Skull Morphology

Mesocephalic Brachycephalic Dolichocephalic

All skull positions are based on 3 factors

• Rotation• Tilt• Flexion-

Extension

3 types of Skull Position change

• 1st type -

• Rotation -your head is rotating on an axis-your neck

• The “NO” position

2nd type of skull position change• Flexion-extension

• Also called “Yes” position

3rd type of skull position change• Tilt

• Or “Maybe” position

Average Skull

Lines/Landmarks/Planes

Radiographic Baselines

AB

C

D

E

Glabellomeatal

Orbitomeatal

Infraorbitomeatal

Acanthiomeatal

Mentomeatal

LANDMARKS IN SKULL XRAY

SAME LINES SHOWN ON A LATERAL XRAY FILM

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

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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)

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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

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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.

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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.

SINUSES PA view

1. Nasal Septum2. Frontal Sinus3. Maxillary Sinus4. Ethmoid Sinus5. Inferior Turbinate6. Odontoid process7. Superior orbital fissure8. Sagittal suture9. Superior orbital fissure10. Coronal suture11. Petrous ridge12. Sphenoid ridge13. Mastoid process14. Innominate line15. Hard palate

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

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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.

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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)

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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

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Chamberlain-Townes

• Breathing Instructions: Suspended respiration• Make exposure• Let patient breathe and relax

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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

SKULLTownes view1. Parietal bone2. Lambdoid suture3. Foramen magnum4. Petrous temporal bone5. Mandible6. Mastoid air cells7. Transverse sinus8. Sphenoid sinus9. Greater wing of

sphenoid10. Temporal tubercle11. Superior sagttal sinus

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

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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)

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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.

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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.

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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.

1. Frontal Sinus2. Maxillary Sinus3. Ethmoid Sinus4. Spenoid Sinus5. Sella Turcica 6. Occipital Bone 7. Mastoid Air Cells8. Floor of posterior fossa9. Anterior arch of C-110. Mandible 11.Coronal Suture

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Lateral Sinus & Skull

• 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

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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.

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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.

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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

• 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

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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.

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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.

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1. Lat. & Med. ptyergoid plate

2. Ethmoid Sinus3. Odontoid Process4. Sphenoid Sinus5. Foramen ovale6. Maxillary Sinus7. Mastoid air cells8. Ant arch of C-19. Margin of foramen

magnum10. Ext. auditory canal11. Foramen spinosum12. Carotid canal13. Cervical spine

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BASE OF SKULL

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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)

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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.

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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.

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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).

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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.

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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.

MAGNIFIED XRAY SCHULLERS VIEW

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Caldwell Sinus Projection

• Patient is seated facing Bucky.

• Ask patient to place their nose and forehead on center line of Bucky.

• Check for rotation.

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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.

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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)

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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

• 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

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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.

SINUSCALDWELL VIEW

FRONTAL SINUS

SPHENOID BONE

MAXILLARY SINUS

INFERIORTURBINATE

MANDIBLE

HARD PALATEMASTOIDAIR CELLS

ORBIT

ETHMOID

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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.

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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)

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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.

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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.

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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

• 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

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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.

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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.

SINUSES1. Frontal sinus2. Ethmoid Sinus3. Nasal Septum (bony)4. Zygomatical-Frontal Suture5. Maxillary Sinus6. Zygoma7. Zygomatic Arch8. Mandible9. Inferior orbital margin10. Left orbit

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AP WATERS VIEW

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XRAY VIEW OF OPTIC FORAMINA

An example of normal Stenvers View

CONED PITUITARY FOSSA VIEW

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

• 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

• 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

Thank you