Radiography of cranial Bones

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Lecture (27)
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Radiography of cranial Bones
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• Basic
• 0Occipito -frontal
• 15 Occipito-frontal ( Caldwell)
• AP Axial 30 Fronto- Occipital ( Townes)
• Sub-mento vertical ( SMV)

• Trauma Series Craniu
• 0 Fronto occipital
• 20 Fronto occipital
• Lateral ( Horizontal Beam )

• Cranium (Sella Turcica) Basic
• Lateral
• AP Axial ( Townes )

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Skull Basic projections ( Cranium Bones )

• Basic
• 0Occipito -frontal
• 15 Occipito-frontal ( Caldwell)
• AP Axial 30 Fronto- Occipital ( Townes)
• Sub-mento vertical ( SMV)

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0 Occipito- frontal

• Exposure factors

KV mAs FFD Focus Grid Film/Screen combination
80 40 100 Fine Yes Regular
Patient Position Patient prone or sits erect
facing the bucky. Part Position Rest patients
nose and forehead against the bucky. Align
midsagittal plane perpendicular to and in line
with the midline of bucky and central ray. Tuck
chin in to bring the OML 90 to film. Centre
bucky to Glabella
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• Central Ray
• Horizontally perpendicular to film holder
• Centre Point
• Exit through the Glabella
• Anatomy Demonstrated
• Frontal bone, crista galli, internal auditory
  canals, frontal and ethmoid sinuses,
• petrous ridges, greater and lesser wings of
  sphenoid bone

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15 Occipito-frontal (Caldwell)

• Exposure factors

KV mAs FFD Focus Grid Film/Screen combination
80 40 100 Fine Yes Regular
Patient Position Patient Prone or sits erect
facing the bucky.
Part Position Rest patients nose and forehead
against the bucky. Align midsagittal plane
perpendicular to and in line with the midline of
bucky and central ray. Tuck chin in to bring the
OML 90 to film. Centre bucky to Nasion
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Central Ray Angled 15 Caudally Centre
Point Exit through the Nasion Anatomy
Demonstrated Frontal bone, crista galli, Orbital
margin, frontal and ethmoid sinuses, petrous
ridges, greater and lesser wings of
sphenoid. Petrous pyramids projected into lower
1/3 of the orbits
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Basic Skull Projections30 Fronto Occipital
(Townes)

• Exposure factors

KV mAs FFD Focus Grid Film/Screen combination
85 40 100 Fine Yes Regular
.Patient Position

• Patient supine or sits erect A.P. against the
  bucky

Part Position Align midsagittal plane
perpendicular to and in line with the midline of
bucky and central ray. Tuck chin in to bring the
OML 90 to film.
Central Ray Angled 30 Caudally centre Point In
the midline to a point 6 cm above the Nasion.
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Anatomy Demonstrated

• Occipital bone, petrous pyramids, foramen magnum,
  dorsum sellae and posterior clinoids
• Dorsum sella and posterior clinoids are projected
  into the foramen magnum.

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Basic Skull ProjectionsLateral (Cranium)

• Exposure factors

KV mAs FFD Focus Grid Film/Screencombination
85 40 100 Fine Yes Regular
Patient Position Patient recumbent semi prone or
sits erect facing the bucky, Part Position
Rotate head to the side in question, to bring the
median Sagittal plane parallel to the film. The
angle of the OMB is adjusted for maximum patient
comfort. The Interpupillary line should be
parallel to the floor.
Central Ray Perpendicular to film holder Centre
Point To a point 2cm superior and 2cm anterior to
the EAM.
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Anatomy Demonstrated

• Lateral aspect of cranium nearest to the film,
  dorsum sella, anterior and posterior clinoids,
  greater and lesser wings of sphenoid bone.
• Mandibular rami, orbital roofs, E.A.M.s and wings
  of sphenoid bone superimposed.
• Sella turcica seen in profile.

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Basic Skull ProjectionsSub-mento vertical ( SMV)

• Exposure factors

KV mAs FFD Focus Grid Film/Screen combination
85 40 100 Fine Yes Regular
Patient Position

• Patient supine or sits erect, with his back to
  the bucky

Part Position
Take care with this technique it is not suitable
for trauma patients a small pillow is placed
behind the shoulders and the patient extends the
neck until the orbital Meatal baseline is
parallel to the film the Interpupillary line
parallel to the floor and the median sagittal
plane at 90 degrees to the film Apply thyroid
protection with lead rubber
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• Central Ray
• Horizontally perpendicular to film holder
• Centre Point
• Midway between the angles of the mandible

Anatomy Demonstrated
Base of skull and associated foramina
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Cranium Bones (Trauma Series)
0 Fronto occipital 20 Fronto occipital
Lateral ( Horizontal Beam )
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0 Fronto occipital

• Exposure factors

KV mAs FFD Focus Grid Film/Screen combination
85 40 100 Fine Yes Regular
Patient Position The patient lies supine on the
trolley or x-ray table
Part Position
The midsagittal plane centred to centre of the
table. The patients head is positioned so that
the Interpupillary line is parallel to the
film. The neck is flexed depressing the chin
until the radiographic baseline (OMBL) is at 90
degrees to the film, Not possible if there is a
possible cervical injury) A small pad may be
needed under the occipital or beneath the cassette
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Central Ray Perpendicular to film holder Centre
Point To the Glabella
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• Anatomy Demonstrated

Frontal bone, crista galli, internal auditory
canals, frontal and ethmoid sinuses, petrous
ridges, greater and lesser wings of sphenoid
bone
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20 Fronto occipital

• Exposure factors

KV mAs FFD Focus Grid Film/Screen combination
85 40 100 Fine Yes Regular
Patient Position The patient lies supine on the
trolley or x-ray table Part Position The
midsagittal plane centred to centre of the
table. The patients head is positioned so that
the interpupillary line is parallel to the
film. The neck is flexed depressing the chin
until the radiographic baseline (OMBL) is at 90
degrees to the film, Not possible if there is a
possible cervical injury) A small pad may be
needed under the occipital or beneath the
cassette
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Central Ray The vertical central ray is angled
20 degrees cranially Centre Point To the Glabella
 Anatomy Demonstrated Frontal bone, crista galli,
Orbital margin, frontal and ethmoid sinuses,
petrous ridges, greater and lesser wings of
sphenoid. Petrous pyramids projected into lower
1/3 of the orbits
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Lateral (Horizontal Beam)

• Exposure factors

KV mAs FFD Focus Grid Film/Screen combination
80 40 100 Fine Yes Regular
Patient Position The patient lies supine on the
trolley or x-ray table Part Position Midsagittal
plane aligned central to the table, The head is
supported on a small pad, Side of interest
nearest the film. the median sagittal plane must
be parallel to the Film is placed vertically
along side of the head.
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• Central Ray
• Horizontally perpendicular to film holder
• Centre Point
• To a point 2cm superior and 2cm anterior to the
  EAM
• Anatomy Demonstrated
• Lateral aspect of cranium nearest to the film,
  dorsum sella, anterior and posterior clinoids,
  greater and lesser wings of sphenoid bone.
• Mandibular rami, orbital roofs, E.A.M.s and wings
  of sphenoid bone superimposed.

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Cranial Bones (Sella Turcica)

• Basic
• Lateral
• AP Axial ( Townes )

• Basic
• Lateral
• AP Axial ( Townes )

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Lateral (Sella)

• Exposure factors

KV mAs FFD Focus Grid Film/Screen combination
85 40 100 Fine Yes Regular
Patient Position Patient recumbent semi prone or
sits erect facing the bucky, Part Position
Rotate head to the side in question Align
Interpupillary line perpendicular to bucky
surface Align midsagittal plane parallel to bucky
surface Collimate to field size approximately 4
inches square Suspend respiration during exposure
Central Ray Perpendicular to film holder Centre
Point To a point 2cm superior and 2cm anterior to
the EAM.
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Anatomy Demonstrated Sella turcica Anterior and
posterior clinoids processes Dorsum sella and
clivus
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Sella 30 Fronto Occipital (Townes)

• Exposure factors

KV mAs FFD Focus Grid Film/Screen combination
85 40 100 Fine Yes Regular
Patient Position Patient supine or sits erect
A.P. against the bucky
Part Position Align midsagittal plane
perpendicular to and in line with the midline of
bucky and central ray. Tuck chin in to bring the
OML 90 to film. Collimate to field size
approximately 4 inches square Suspend respiration
during exposure
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Central Ray Angled 37 Caudally for dorsum sellae
and posterior clinoid processes Angled 30
Caudally for anterior clinoid processes Centre
Point In the midline to a point 1 ½ inch above
superciliary arch Anatomy Demonstrated Dorsum
sella, anterior and posterior clinoids
processes( Depending on CR angulation) Foramen
Magnum Occipital Bone