Lecture (27)
Radiography of cranial
Bones
– Basic
0°Occipito -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 )
Skull Basic projections ( Cranium Bones )
– Basic
• 0°Occipito -frontal
• 15° Occipito-frontal ( Caldwell)
• AP Axial 30° Fronto- Occipital ( Townes)
• Sub-mento vertical ( SMV)
0° Occipito- frontal
• Exposure factors
KV
mAs
FFD
Focus
Grid
80
40
100
Fine
Yes
Patient Position
Patient prone or sits erect facing the bucky.
Part Position
Rest patient’s 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
Film/Screen
combination
Regular
•
•
•
•
•
•
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
15° Occipito-frontal (Caldwell)
• Exposure factors
KV
mAs
FFD
Focus
Grid
80
40
100
Fine
Yes
Film/Screen
combination
Regular
Patient Position
Patient Prone or sits erect facing the bucky.
Part Position
Rest patient’s 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
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
Basic Skull Projections
30° Fronto Occipital (Townes)
• Exposure factors
KV
mAs
FFD
Focus
Grid
85
40
100
Fine
Yes
Film/Screen
combination
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.
Anatomy Demonstrated
• Occipital bone, petrous pyramids, foramen magnum, dorsum sellae
and posterior clinoids
• Dorsum sella and posterior clinoids are projected into the foramen
magnum.
Basic Skull Projections
Lateral (Cranium)
• Exposure factors
KV
mAs
FFD
Focus
Grid
Film/Screenco
mbination
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.
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.
Basic Skull Projections
Sub-mento vertical ( SMV)
• Exposure factors
KV
mAs
FFD
Focus
Grid
85
40
100
Fine
Yes
Film/Screen
combinati
on
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
• Central Ray
•
Horizontally & perpendicular to film holder
• Centre Point
•
Midway between the angles of the mandible
Anatomy Demonstrated
Base of skull and associated foramina
Cranium Bones (Trauma Series)
0° Fronto occipital
20° Fronto occipital
Lateral ( Horizontal Beam )
0° Fronto occipital
• Exposure factors
KV
mAs
FFD
Focus
Grid
85
40
100
Fine
Yes
Film/Screen
combination
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
Central Ray
Perpendicular to film holder
Centre Point
To the Glabella
• Anatomy Demonstrated
Frontal bone, crista galli, internal auditory canals, frontal and
ethmoid sinuses,
petrous ridges, greater and lesser wings of sphenoid bone
20° Fronto occipital
Exposure factors
KV
mAs
FFD
Focus
Grid
85
40
100
Fine
Yes
Film/Screen combination
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
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
Lateral (Horizontal Beam)
Exposure factors
KV
mAs
FFD
Focus
Grid
80
40
100
Fine
Yes
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.
Film/Screen
combination
Regular
•
•
•
•
•
•
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
.
Cranial Bones (Sella Turcica)
•
Basic
– Lateral
• AP Axial ( Townes )
Basic
Lateral
AP Axial ( Townes )
Lateral (Sella)
• Exposure factors
KV
mAs
FFD
Focus
Grid
85
40
100
Fine
Yes
Film/Screen
combination
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.
Anatomy Demonstrated
Sella turcica
Anterior and posterior clinoids processes
Dorsum sella and clivus
Sella 30° Fronto Occipital (Townes)
• Exposure factors
KV
mAs
FFD
Focus
Grid
Film/Screen
combinat
ion
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
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