Radiography of the Orbits
Fall 2009
FINAL
Function of Orbits
Serve as bony sockets for the eyeballs
Openings for nerves and blood vessels
Bones of the Orbits - 7
Division of the Orbits
________________
–Primarily composed of orbital plate of frontal bone
________________
–Zygoma (small amount)
–Maxilla
–Palatine
3. _______________
–Medial
•Lacrimal
–Lateral
•Zygoma (large amount)
Base of the Orbit
The circumference is
made of 3 bones:
_________________
_________________
_________________
Openings in Posterior Orbit
______________
–Optic canal
–Sphenoid strut
______________
______________
ANGLE OF ORBITS
Each orbit projects
–30 degrees superiorly
–37 degrees toward MSP
Indications for Orbit and Eye Radiography
Possible Fractures
Blowout
Tripod
Lefort
Foreign body of the eye
Mechanisms producing
Orbital Fractures
Auto accidents
Assault
Falls, sports, and industrial accidents
Blowout Fracture
Blowout Fracture
Blow to the eye
Orbital floor is fractured
Soft tissue herniates into maxillary sinuses
Often have ocular injury
_____________________
Blowout Fracture
______________________
Tripod Fracture
Direct blow to zygoma
Visual concave abnormalities
Usually orbits are involved
4. Free floating zygoma
LeFort
Fractures
LeFort types II & III involve the orbits
Lefort II and III
LeFort Fractures
Type II
Separation through:
 frontal processes
 lacrimal bones
orbit floors,
zygomaticomaxillary suture line
 lateral wall of maxillary sinuses
 pterygoid
Complications
____________ system obstruction
Infraorbital nerve anesthesia
____________
Malocclusion
Lefort 2
LeFort Fractures
Type III
Separation
of mid third of face at:
zygomaticotemporal
naso-frontal sutures
 and across orbital floors
Complications
_________________

Mal-union
_________________
Lenthening of
mid face
_________________
system obstruction
LEFORT 3
LEFORT 3
Basic and Special Projections
Orbits
Basic
•_________________
•_________________
Special
•_________________
Eyes
Basic
•_______________
•_______________
•_______________
Parietoacanthial Projection
Waters Method
Positioning
____________
____________
Lines and planes:
____________
____________
CR:
 ___________
Parietoacanthial Projection
Waters Method Radiograph
Distance from lateral border of skull and orbit equal on each side
Petrous ridges projected immediately below maxillary sinuses
Parietoacanthial Projection Modified Waters
Positioning:
_____________
Lines and planes
_____________
_____________
CR
 ____________
Modified Waters Radiographs
Petrous ridges projected immediately below the inferior border of the orbits
Equal distance from lateral orbit to lateral skull on both sides
Modified Parietoacanthial
Modified Waters method
Modified Waters
Radiograph & Diagram
Acanthioparietal Projection
Reverse Waters Method
Positioning
_______________
Lines and planes
_______________
_______________
CR
_______________
Reverse Waters Radiograph
Distance from lateral border of skull and orbit equal on each side
Petrous ridges projected immediately below maxillary sinuses
Parietoorbital Projection (Rhese Method)
(PA) Optic Canal and Foramen
Positioning
______________
______________
Lines and planes:
______________
______________
PA- CR:
 enters 1”superior and posterior to TEA
PA- CR:
 exits through the affected orbit
Parietoorbital Projection (Rhese Method)
(PA) Optic Canal and Foramen Radiograph
Optic canal & foramen visible at end of sphenoid ridge in inferior & lateral quadrant of
orbit
Entire orbital
Supraorbital
Close
rim
margins lying in same horizontal plane
beam restriction to the orbital region
Rhese Diagram and Radiograph
Rhese Method
(AP) Optic Canal and Foramen
Positioning:
_______________
_______________
Lines and planes:
_______________
_______________
AP- CR:
 _______________
Rhese Method
(AP) Optic Canal and Foramen Radiograph
Optic canal & foramen visible at end of sphenoid ridge in inferior & lateral quadrant of
orbit
Entire orbital
Supraorbital
Close
rim
margins lying in same horizontal plane
beam restriction top the orbital region
Rhese Radiograph and Diagram
Foreign objects in the EYE
Lateral Projection (EYE)
Positioning:
Semiprone or seated upright
Affected eye closest to cassette
___________________
Lines and planes:
MSP parallel
IPL perpendicular
CR:
___________________
Lateral Eye for Foreign Body
Density & contrast permitting optimal visibility of orbit and foreign bodies
SI orbital roofs
Close beam restriction
PA Axial (EYE)
Positioning
Forehead & nose on IR.
Center IR ¾ “ distal to nasion
________________
Lines and planes:
________________
CR:
Through center of orbits, 30 degrees caudal
PA Axial Eye Radiograph
Petrous pyramids lying below orbital shadows
No rotation of cranium
Close beam restriction
Modified Waters
(EYE)
Positioning:
IR at level of orbits
Rest pt’s chin on IR
Instruct pt to close eyes and hold eyes still
Lines and planes:
MSP perp
 OML 50 degrees
CR:
Perp
through mid-orbits
Modified Waters Radiograph
Petrous Pyramids lying well below orbital shadows
Symmetric visualization of orbits
Close beam restriction
LETS REVIEW
Seven Bones of the Orbit
Openings and Supporting Structures of Openings of the Orbit
Parietoorbital Oblique Projection of Orbits
References
Ballinger, P.W. & Frank, E.D. (1999).
Merrill’s atlas of radiographic positions and radiologic procedures. V2. New
York: Mosby
Ponsell, M.R. (2003). Assessing facial fractures in the emergency room. New Jersey
Richardson, M.L. (2000). Facial and mandibular fractures. Retrieved May 5, 2007 from:
http//www.rad.washington.edu/mskbook/facialfx.html