lecture (27)
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Lecture (27)
Radiography of cranial Bones
– Basic0°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) BasicLateral
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 Film/Screen combination
80 40 100 Fine Yes Regular
Patient PositionPatient prone or sits erect facing the bucky.Part PositionRest 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
• 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 Film/Screen combination
80 40 100 Fine Yes Regular
Patient PositionPatient Prone or sits erect facing the bucky.
Part PositionRest 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 RayAngled 15° Caudally Centre PointExit through the NasionAnatomy DemonstratedFrontal 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 Projections30° Fronto Occipital (Townes)
• Exposure factors
KV mAs FFD Focus Grid Film/Screen combination
85 40 100 Fine Yes Regular
.Patient PositionPatient supine or sits erect A.P. against the buckyPart PositionAlign 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 RayAngled 30° Caudallycentre PointIn 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/Screencom
bination
85 40 100 Fine Yes RegularPatient PositionPatient 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 RayPerpendicular to film holder Centre PointTo 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 ProjectionsSub-mento vertical ( SMV)
• Exposure factors
KV mAs FFD Focus Grid Film/Screen combinati
on
85 40 100 Fine Yes Regular
Patient PositionPatient supine or sits erect, with his back to the buckyPart Position
Take care with this technique; it is not suitable for trauma patientsa small pillow is placed behind the shoulders and the patient extends the neck until the orbital Meatal baseline is parallel to the filmthe 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 Film/Screen combination
85 40 100 Fine Yes Regular
Patient PositionThe patient lies supine on the trolley or x-ray tablePart 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 holderCentre PointTo the Glabella
• Anatomy Demonstrated
Frontal bone, crista galli, internal auditory canals, frontal and ethmoid sinuses, petrous ridges, greater and lesser wings of sphenoid bone
Exposure factors
20° Fronto occipital
KV mAs FFD Focus Grid Film/Screen combination
85 40 100 Fine Yes Regular
Patient PositionThe patient lies supine on the trolley or x-ray tablePart PositionThe 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 craniallyCentre PointTo the Glabella
Anatomy DemonstratedFrontal 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
Exposure factors
Lateral (Horizontal Beam)
KV mAs FFD Focus Grid Film/Screen combination
80 40 100 Fine Yes RegularPatient PositionThe patient lies supine on the trolley or x-ray tablePart PositionMidsagittal 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.
• 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 )
BasicLateral
AP Axial ( Townes )
Lateral (Sella) • Exposure factors
KV mAs FFD Focus Grid Film/Screen combination
85 40 100 Fine Yes Regular
Patient PositionPatient recumbent semi prone or sits erect facing the bucky,Part Position Rotate head to the side in questionAlign Interpupillary line perpendicular to bucky surfaceAlign midsagittal plane parallel to bucky surfaceCollimate to field size approximately 4 inches squareSuspend respiration during exposureCentral RayPerpendicular to film holder Centre PointTo a point 2cm superior and 2cm anterior to the EAM.
Anatomy DemonstratedSella turcica Anterior and posterior clinoids processesDorsum sella and clivus
Sella 30° Fronto Occipital (Townes)• Exposure factors
KV mAs FFD Focus Grid Film/Screen combinat
ion
85 40 100 Fine Yes RegularPatient PositionPatient supine or sits erect A.P. against the buckyPart PositionAlign 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 squareSuspend respiration during exposure
Central RayAngled 37° Caudally for dorsum sellae and posterior clinoid processesAngled 30° Caudally for anterior clinoid processesCentre PointIn the midline to a point 1& ½ inch above superciliary archAnatomy DemonstratedDorsum sella, anterior and posterior clinoids processes( Depending on CR angulation)Foramen MagnumOccipital Bone
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