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Skull & cranial bones extra
handout
By
Dr. Mohsen Dashti
Imaging Procedures 362
March 15 & 18, 2009
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Anatomy Review
Skull
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Slide 2
Skull Anatomy
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Comprised of 22 separate bones divided into
two groups:
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Cranial bones – 8
Facial bones – 14
Cranial bones further subdivided into
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Calvaria
Floor
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Slide 3
Skull Anatomy
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Diploë = inner layer of spongy bone
separating two outer plates of compact tissue
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Composition of calvarium bones
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Slide 4
Anterior view of skull
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Slide 5
Lateral view of skull
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Slide 6
Cranial Bones
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Calvaria
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Frontal
Occipital
R. parietal
L. parietal
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Floor
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Ethmoid
Sphenoid
R. temporal
L. temporal
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Slide 7
Superior view of cranial floor
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Slide 8
Skull Anatomy
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Sutures = fibrous joints that connect the
bones of the skull
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Coronal = between frontal and parietal bones
 Sagittal = on top of head between two parietal
bones
 Squamosal = between temporal bone and the
parietal bones
 Lambdoidal = between occipital and the parietal
bones
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Slide 9
Skull Anatomy
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Bregma = junction of coronal and sagittal
sutures
Lambda = junction of sagittal and lambdoidal
suture
Fontanels = areas of incomplete ossification
in Infant skulls, i.e., “soft spots”
Adult cranial size usually achieved by age 12
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Slide 10
Cranial Floor
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Internally, divided into three regions
Anterior cranial fossa – houses frontal lobes of
cerebrum; extends from anterior frontal bone to
lesser wings of sphenoid
 Middle cranial fossa – houses temporal lobes;
extends from lesser wings of sphenoid to apices of
petrous ridges
 Posterior cranial fossa – deep depression
posterior to petrous ridges; protects cerebellum,
pons, and medulla oblongata
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Slide 11
Skull Morphology
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Typical skull = mesocephalic
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Petrous pyramids project anteriorly and medially
at angle of 47 degrees from MSP
Brachycephalic skull
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Petrous pyramids project anteriorly and medially
at angle of 54 degrees from MSP
Short from front to back, broad from side to side,
and shallow from vertex to base
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Slide 12
Skull Morphology
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Dolichocephalic skull
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Petrous pyramids project anteriorly and medially
at angle of 40 degrees from MSP
Long from front to back, narrow from side to side,
and deep from vertex to base
Asymmetry of outer features should be noted
while positioning; for example, the nose may
not always be in the midline
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Slide 13
Frontal Bone
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Has vertical portion (frontal squama) and
horizontal portions
Frontal squama forms forehead and anterior
part of cranial vault
Horizontal portions form orbital plates, part of
roof of nasal cavity, and greater part of
anterior cranial fossa
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Slide 14
Frontal Bone
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Landmarks to note
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Frontal eminences
Supraorbital margins
Supraciliary arches
Supraorbital foramina
Glabella
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Slide 15
Frontal Bone
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Frontal sinuses contained between the two
tables of squama on each side of MSP
Articulates with R and L parietals, sphenoid,
and ethmoid, nasal bones, and zygoma
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Slide 16
Frontal Bone
Anterior view
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Slide 17
Ethmoid Bone
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Consists of
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Horizontal plate
Vertical plate
Two light, spongy masses = labyrinths
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Slide 18
Ethmoid Bone
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Located between the orbits and forms part of
anterior cranial fossa, nasal cavity, orbital
walls, and bony nasal septum
Horizontal portion is called cribriform plate
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Slide 19
Ethmoid Bone
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Cribriform plate contains numerous foramina
for transmission of olfactory nerves
Crista galli = conical projection at anterior
midline of cribriform plate
Perpendicular plate = vertical portion; forms
superior portion of bony nasal septum
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Slide 20
Ethmoid Bone
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Labyrinths
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Contain ethmoid sinuses or air cells
Walls form part of medial walls of orbits and lateral
walls of nasal cavity
Have two thin, scroll-shaped projections = superior
and middle nasal conchae
Articulates with frontal, sphenoid, lacrimal,
maxilla, and vomer
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Slide 21
Ethmoid Bone
Anterior view
Lateral view
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Slide 22
Parietal Bones
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Somewhat square-shaped
Have a convex external surface and concave
internal surface
Parietal eminence = prominent bulge near
center of external surface of each bone
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This is the point where the width of the skull
should be measured to set technique
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Slide 23
Parietal Bones
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Articulate with each other at the sagittal
suture in MSP, the frontal, temporal, occipital,
and sphenoid bones
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Slide 24
Parietal Bones
Interior view
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Slide 25
Sphenoid Bone
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Irregular, wedge-shaped bone that resembles
a bat (somewhat)
Located in base of cranium anterior to
temporal bones and basilar portion of
occipital
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Slide 26
Sphenoid Bone
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Consists of
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Body
Two lesser wings
Two greater wings
Two pterygoid processes
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Slide 27
Sphenoid Bone
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Body contains two sphenoid sinuses and
forms posterior bony wall of nasal cavity
Sella turcica = deep depression on superior
surface of body
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Houses pituitary gland
Located in MSP of cranium ¾ anterior and
superior to EAM
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Slide 28
Sphenoid Bone
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Tuberculum sellae = anterior border of sella
Dorsum sellae = posterior border of sella
Posterior clinoid processes = top borders of
dorsum
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Slide 29
Sphenoid Bone
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Clivus = slanted area of bone posterior and
inferior to dorsum
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Continuous with basilar area of occipital
Supports pons of the brain
Optic groove extends across anterior portion
of tuberculum sellae
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Groove ends on each side at the optic canal
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Slide 30
Sphenoid Bone
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Optic canal = opening into the apex of orbit
for transmission of optic nerve and
ophthalmic artery
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Actual opening is termed optic foramen
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Slide 31
Sphenoid Bone
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Lesser wings arise from anterior and superior
portion of body and lie horizontally on each
side
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Form posteromedial portion of orbital roofs, the
posterior portion of anterior cranial fossa, upper
margin of superior orbital fissure, and optic canals
Medial ends form the anterior clinoid processes
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Slide 32
Sphenoid Bone
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Greater wings arise from sides of body and
curve laterally, posteriorly, anteriorly, and
superiorly
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Form part of middle cranial fossa and
posterolateral walls of orbit
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Slide 33
Sphenoid Bone
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Three paired foramina situated on greater
wings
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Rotundum
Ovale
Spinosum
Pterygoid processes arise from lateral
portions of inferior surface of body and medial
portions of inferior surfaces of greater wings
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Slide 34
Sphenoid Bone
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Pterygoids articulate with
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Palantine bones anteriorly
Vomer as part of the nasal cavity
Sphenoid articulates with each of the other
seven bones of the cranium and the zygoma
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Slide 35
Sphenoid Bone
Lateral view
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Slide 36
Occipital Bone
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Situated at posteroinferior part of cranium
Forms posterior half of cranial base and
greater portion of posterior cranial fossa
Has four parts
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Squama
Two occipital condyles
Basilar portion
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Slide 37
Occipital Bone
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Foramen magnum = large opening through
which the medulla oblongata passes as it
exits cranium
External occipital protuberance = prominent
process on squama
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Also called inion
Corresponds to internal occipital protuberance
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Slide 38
Occipital Bone
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Occipital condyles = project anteriorly from
each side of squama
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Fuse at basilar portion to complete foramen
magnum
Articulates with the two parietals, the two
temporals, the sphenoid, and the atlas (C1)
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Slide 39
Occipital Bone
Posterior view
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Slide 40
Occipital Bone
Lateral view
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Slide 41
Temporal Bones
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Situated on each side of cranial base
between greater wings of sphenoid and
occipital bone
Form large part of middle cranial fossa and a
small part of posterior cranial fossa
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Slide 42
Temporal Bones
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Consist of
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Squamous portion
Tympanic portion
Styloid process
Zygomatic process
Petromastoid portion which contain the organs for
hearing and equilibrium
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Slide 43
Temporal Bones
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Squamous portion = thin, upper portion of
temporal bone
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Forms part of side wall of cranium
Zygomatic process = prominent arched
process that projects anteriorly to articulate
with zygoma and complete the zygomatic
arch
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Slide 44
Temporal Bones
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Articular tubercle = located on inferior border
of zygomatic process
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Forms anterior boundary of mandibular fossa
Mandibular fossa = receives condyle of
mandible to form temporomandibular joint
(TMJ)
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Slide 45
Temporal Bones
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Tympanic portion = located below squama
and in front of petromastoid portion
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Forms anterior wall, inferior wall and part of
posterior walls of the EAM
Styloid process = slender, pointed bone
projecting inferiorly, anteriorly, and slightly
medially from inferior surface of tympanic
portion
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Slide 46
Temporal Bones
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Petromastoid portion combines petrous and
mastoid portions
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Forms the inferior, posterior part of the temporal
bone
Articulates with parietal bone at its superior border
and with occipital bone at its posterior border
Usually contains air cells, which vary greatly in
size, number, and pneumatization
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Slide 47
Temporal Bones
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Mastoid process = conical process projecting
from mastoid portion
Petrous portion projects medially and
anteriorly between greater wing of sphenoid
and occipital bone
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Also called petrous pyramid
Conical or pyramidal in shape
Thickest and densest portion of cranium
Contains the organs of hearing and balance
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Slide 48
Temporal Bones
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Auditory ossicles = bones of middle ear
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Malleus
Incus
Stapes
Temporal bone articulates with the parietal,
occipital, sphenoid, zygoma, and mandible
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Slide 49
Temporal Bones
Lateral view
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Slide 50
Temporal Bones
Anterior view
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Slide 51
Procedural Considerations
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Skull topography
Skull morphology
General body position
Cleanliness
Radiation protection
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Slide 52
Skull Topography
Be able to locate the following landmarks:
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Glabella
Inner canthus
Outer canthus
Nasion
Infraorbital margin
Acanthion
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Gonion
Mental point
External auditory
meatus (EAM)
Auricular point
Top of ear attachment
(TEA)
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Slide 53
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Slide 54
Radiographic Landmarks
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Orbitomeatal line (OML)
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Infraorbitomeatal line (IOML)
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From outer canthus to EAM
From infraorbital margin to EAM
Glabellomeatal line (GML)
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From glabella to EAM
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Slide 55
Radiographic Landmarks
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Interpupillary line (IPL)
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Acanthiomeatal line (AML)
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Perpendicular line between pupils of eyes
From acanthion to EAM
Mentomeatal line (MML)
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From mental point (center of chin) to EAM
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Slide 56
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Slide 57
Skull Morphology
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Radiographic positioning guidelines are
based on mesocephalic skull size and shape
Adjustments to centering and CR and/or part
angulation may be required when working
with patients with atypical skull shapes
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Slide 58
General Body Position
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Patient may be examined in upright or
recumbent positions
General body position is especially important
in hyposthenic, asthenic, and hypersthenic
body types
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Slide 59
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Slide 60
General Body Position
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Hyposthenic/asthenic patients usually need
support at chest to elevate C-spine
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Helps prevent downward tilt of MSP
Hypersthenic patients require radiolucent
support at head
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Helps prevent upward tilt of MSP
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Slide 61
Hyposthenic/Asthenic Patients
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Slide 62
Hypersthenic Patients
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Slide 63
Cleanliness
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Hair and skin of face are naturally oily; illness
often increases oiliness
Cranial procedures require direct contact of
patient’s face with VBS
Clean device after each patient
Wash your hands!!!
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Slide 64
Radiation Protection
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Collimate to anatomy of interest
Shield gonads/abdomen of pediatric patients
and those of reproductive age
Shield thyroid and thymus of pediatric patient
when doing so will not interfere with
demonstration of anatomy of interest
Good communication and positioning skills
reduce chance of need for repeat radiographs
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Slide 65
Patient Preparation
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Remove all radiopaque artifacts
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Eyeglasses
Dentures and partial plates
Hearing aids
Jewelry
Wigs/hairpieces
Hairpins, barrettes, and pony tail holders
False eyes
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Slide 66
Essential Projections: Cranium
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Lateral
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Right and left lateral positions
Dorsal decubitus position
PA
PA axial (Caldwell method)
AP
AP axial
AP axial (Towne method)
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Slide 67
Essential Projections: Cranium
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PA axial (Haas method)
Submentovertical (SMV)
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For cranial base
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Slide 68
Lateral Projection
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Patient position
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Seated upright or semiprone
Part position
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MSP of head parallel to IR
IPL perpendicular
IOML parallel to transverse axis of cassette
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Slide 69
Lateral Projection
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CR
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Perpendicular to center of IR
Enters 2 superior to EAM
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Slide 70
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Slide 71
Lateral Projection
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Patient position
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Dorsal decubitus
Part position
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Elevate head on radiolucent support to center to
vertical IR
MSP of head vertical
IPL perpendicular to IR
IOML parallel to transverse axis of cassette
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Slide 72
Lateral Projection
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CR
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Horizontal and perpendicular to center of IR
Enters 2 superior to EAM
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Slide 73
Lateral Projection
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Patient position
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Supine or semisupine
Part position
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Elevate head on radiolucent support to place MSP
parallel and IPL perpendicular
Turn head toward side of interest
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Slide 74
Lateral Projection
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CR
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Perpendicular to center of IR
Enters 2 superior to EAM
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Slide 75
PA/PA Axial (Caldwell)
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Patient position
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Seated erect or prone
MSP centered to midline
Forehead and nose resting on table or upright
Bucky
Part position
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OML perpendicular to IR plane
MSP perpendicular to IR
IR centered to nasion
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Slide 76
PA/PA Axial (Caldwell)
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CR for PA projection
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Perpendicular
Exits nasion
CR for PA axial (Caldwell)
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Angled 15 degrees caudad
Exits nasion
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Slide 77
AP/AP Axial Projection
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Note: Provides similar but magnified image
when patient cannot be positioned for PA or
PA axial projection.
Patient and part position
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Supine
MSP centered to midline
MSP and OML perpendicular to IR
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Slide 78
AP/AP Axial Projection
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CR
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Perpendicular or 15 degrees cephalad for AP axial
projection
Enters nasion
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Slide 79
AP Axial (Towne Method)
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Patient and part position
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Supine or seated erect
MSP centered to midline
MSP perpendicular
OML or IOML perpendicular
IR top border level with skull vertex
IR center at or near foramen magnum
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Slide 80
AP Axial (Towne Method)
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CR
 Directed through foramen magnum
 OML – 30 degrees caudal
 IOML – 37 degrees caudal
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Slide 81
PA Axial (Haas)
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Patient position
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Prone or seated upright
MSP centered to midline
Shoulders in same horizontal plane
Part position
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Forehead and nose on table
MSP perpendicular
OML perpendicular to IR
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Slide 82
PA Axial (Haas)
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CR
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Directed cephalad at angle of 25 degrees to OML
Enters at a point 1.5 (3.8 cm) below external
occipital protuberance
Exits 1.5 (3.8 cm) superior to nasion
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 83
SMV Projection (Schüller)

Patient position



Seated upright or supine
Torso elevated if supine
Part position



MSP centered to midline
IOML parallel with IR
MSP perpendicular to IR
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 84
SMV Projection (Schüller)

CR




Through sella turcica perpendicular to IOML
Enters MSP of throat between angles of mandible
Passes through a point ¾ (1.9 cm) anterior to
level of EAM
Center IR to CR
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 85
Essential Projections:
Temporal Bone



Axiolateral oblique (modified Law)
Axiolateral oblique (Stenvers)
Axiolateral oblique (Arcelin)
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 86
Axiolateral Oblique (Modified Law)

Patient position



Prone or seated upright
Tape auricle forward
Part position




Place head in true lateral position with affected
side closer to IR
IOML parallel with IR
IPL perpendicular to IR
MSP angled 15 degrees toward IR
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 87
Axiolateral Oblique (Modified Law)

CR



Angled 15 degrees caudad to midpoint of IR
Exits mastoid tip closer to IR about 1 (2.5 cm)
posterior to EAM
Enters 2 (5 cm) posterior to and superior to upper
EAM
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 88
Axiolateral Oblique (Stenvers)

Patient position


Prone or seated upright
Part position



Rest head on forehead, nose, and cheek with side
of interest on IR
IOML parallel with transverse axis of IR
MSP at 45-degree angle from IR
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 89
Axiolateral Oblique (Stenvers)

CR




Angled 12 degrees cephalad
Enters about 3 to 4 (7.6 to 10 cm) posterior and
½ (1.3 cm) inferior to upside EAM
Exits 1 (2.5 cm) anterior to downside EAM
IR and CR centered
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 90
Axiolateral Oblique Temporal Bone
(Arcelin)

Patient position



Supine
MSP centered to midline
Part position


Rotate face away from side of interest to place
MSP at 45-degree angle with plane of IR
IOML perpendicular to IR
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 91
Axiolateral Oblique Temporal Bone
(Arcelin)

CR



Angled 10 degrees caudad
Enters temporal area at 1 (2.5 cm) anterior to
EAM and ¾ (1.9) cm above it
Center IR and CR
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 92
Essential Projections: Optic Canal and
Foramen

Parietoorbital oblique (Rhese method)
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 93
Parietoorbital Oblique (Rhese)

Patient position


Semiprone or seated upright
Part position




Center affected orbit to center of IR
Rest zygoma, nose, and chin on table or upright
Bucky
AML perpendicular to IR
MSP forms 53-degree angle with IR plane
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 94
Parietoorbital Oblique (Rhese)

CR



Perpendicular to IR center
Enters 1 (2.5 cm) superior and posterior to
upside TE
Exits orbit closer to IR
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 95
Lesson 2
Image Critique
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 96
Lateral Projections







Entire cranium without rotation or tilt
Superimposed orbital roofs and greater
wings of sphenoid
Superimposed mastoid regions and EAMs
Superimposed TMJs
Sella turcica in profile
Penetration of parietal region
No overlap of C-spine by mandible
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 97
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 98
PA Projection


Entire cranial perimeter showing three tables
of squamous bone
No rotation


Equal distance from lateral borders of skull to
lateral border of orbits
Symmetric petrous ridges
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 99
PA Projection


Petrous ridges fill orbits
Penetration of frontal bone without excessive
density at lateral borders of skull
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 100
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 101
PA Axial (Caldwell Method)

Same as for PA projection, except

Petrous ridges demonstrated in lower one third
of orbit
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 102
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 103
AP/AP Axial Projection


Same as PA and PA axial projections
Anatomy more magnified in AP and AP axial
projections
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 104
AP Axial (Towne Method)

No rotation




Equal distance from lateral border of skull to
lateral margin or foramen magnum
Symmetric petrous ridges
Dorsum sellae and posterior clinoid
processes visible within foramen magnum
Penetration of occipital bone without
excessive density at parietals
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 105
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 106
PA Axial (Haas)




Projection of dorsum sellae and posterior
clinoid processes within foramen magnum
Equal distance from lateral border of skull to
lateral margin of foramen magnum
Symmetric petrous pyramids
Entire cranium
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 107
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 108
SMV Projection (Schüller)

No rotation or tilt



Equal distance from lateral border of skull to
mandibular condyles
Symmetric petrous pyramids
Penetration sufficient to demonstrate
structures of cranial base
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 109
SMV Projection (Schüller)


Superimposition of mental protuberance over
anterior frontal bone, indicating full neck
extension
Mandibular condyles anterior to petrous
pyramids
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 110
SMV Projection (Schüller)


Superimposition of mental protuberance over
frontal bone – indicates full neck extension
Condyles of mandible anterior to petrous
pyramids
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 111
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 112
Axiolateral Oblique Temporal Bone
(Modified Law)







Mastoid process closer to IR
Air cells centered to IR
Opposite mastoid process inferior and
anterior mastoid of interest
Auricle of ear not superimposing mastoid
Superimposition of IAM and EAM
TMJ visible anterior to mastoid process
Close beam restriction
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 113
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 114
Axiolateral Oblique Temporal Bone
(Stenvers)



Petromastoid portion in profile
Lateral border of skull to lateral border of orbit
Petrous ridge extended to a point about two
thirds up lateral border of orbit
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 115
Axiolateral Oblique Temporal Bone
(Stenvers)




Mastoid process in profile below cranium
Posterior margin of mandibular ramus
superimposing lateral border of C-spine
Mandibular condyle projecting over atlas near
petrosa
Close beam restriction
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 116
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 117
Axiolateral Oblique Temporal Bone
(Arcelin)



Petromastoid portion in profile
Lateral border of skull to lateral border of orbit
Petrous ridge lying horizontal about two thirds
up lateral border of orbit
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 118
Axiolateral Oblique Temporal Bone
(Arcelin)




Mastoid process in profile below cranium
Posterior margin of mandibular ramus
superimposing lateral border of C-spine
Mandibular condyle projecting over atlas near
petrosa
Close beam restriction
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 119
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 120
Parietoorbital Oblique (Rhese)




Optic canal and foramen visible at end of
sphenoid ridge in inferior and lateral quadrant
of orbit
Entire orbital rim
Supraorbital margins lying in same horizontal
line
Close beam restriction to orbit
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 121
Mosby items and derived items © 2007, 2003, 1999 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 122